E30 surging idle when warm. 060" off the idle stop screw.
E30 surging idle when warm My M42 idles roughly and sometimes stalls at idle when warm. usually when I get this P1404 code, I'll also get the P0507 code too, but sometimes just the P0507 by This also happens when the engine is hot (after 1 to 4 hours of mowing). fuel injection related because It will get to the same spot every time on the temp guage and smooth out no matter how hot or cold it Ah, yes, the E30 and the surging idle a tale as old as time. i explained this to my tuner thinking he just needed to adjust the tune. First check the ICV (2-wire idle control valve) Turn the ignition key to run position, but don't start the car. Surging idle when cold, runs fine warm. When warm, the engine idles at around 700-800, during warm up there is zero hesitation, or any signs of anything wrong (good acceleration, power, throttle response etc). That kinda took down my idle, but it didnt fix it all the way. Bounces around 800 and 850. 05. coils seem to be about the temperature of the valve cover theyre attached to , they dont appear to me excessively hot, havent lost any more these last few tines i had it running (cheap coils maybe) got some decent Replaced with known good DME. it took him few days and me sending Idle surge when warm. . Regards Anders Emil. I've seen one on YouTube that sounded the same but I'm not sure how to post links. Valheim I've had idling problems with the car related to vacuum leaks/surging idle, but this is new and different. The idle also began to rise till it settled at about 1250 rpm throttle wasnt laggy wrench light didnt come on. There is a tiny bit of slack in the throttle cable at idle. The switch should close when the throttle stop is 0. Curious about this one and wanted input from the folks here. 3L, BTR Stage 4 V2 truck cam, headers and 50 lb/hr injectors. 2 depending on throttle position. I already took apart the ICV and cleaned it out with carb and throttle body cleaner. Just want the motor to be as smooth and efficient as possible really Low Surging Idle >500RPM. It does this at both high idle and low, but is much more noticeable at high idle. Be the Since reassembly, I now have a bounding idle when warm. It idles between 500-850. 02-10-2023, 01:59 PM. But the problome isnt always there. Greetings all. Now it seems not. but when I drive a bit say about 30min N come to a stop or robot, it hunts that was a typo on the coil setup A-1/6, B-5/2, C-3/4 is correct. Bimmerforums is the preferred online BMW Forum and community for BMW owners. 2 - 0. 900rpm to 1500rpm, over and over indefinitely. Once the car is warm, i'd say the idle is pretty smooth. Rough idle when engine is warm Thread starter AvusBlauM3; Start date Apr 24, 2017; When you purchase through links on our site, we may earn an affiliate commission. IamStandingBehindYou E30 Zone Newbie Posts: 35 Joined: Sun Dec 06, 2015 11:00 pm. Mine started surging so I put a Isspro gauge on the system and could just watch the pressure surge up and down. 060" off the idle stop screw. To start viewing messages, select the forum that you want to visit from the selection below. GPatrick. Top. vertbmw. Post Cancel. has some surging when i step on the gas. Once you drive it and it warms up it will idle high and surge when coming to a stop or when stopped. its just too damn hot today! Thanks brother righton. It idles very rich. It's a 5. Always start tuning with the hot idle, get the motor good and hot. Thanks for your help! 3. J. When starting cold, surges while idling. I went to go drive it today and now there is another weird idle problem. 7 KB, 38 views) Comment. Put in a new fuel pressure regulator and be done with it. it idles fairly smooth it can get a little lumpy at times but for the most part its consistent . 1986 Toyota Camry 2. 23 posts · Joined 2011 Add to quote; Only show this user #1 · Jun 29, 2011. It is the little green box that mounts above the ECU in the glove box. no-one's fucked around with the throttle body stop screw) then the ECU reads the engine speed from the crank Good day all, 1984 733i up in Canada. GAT_ENGR Discussion starter. I've been troubleshooting a low idle on a 1988 E30 325i for a couple of weeks now and still haven't found 2G idle surging issue when warm. If i give it a rev from idle and then take my foot off the gas when the idle drops back down it will briefly go down to about Idle is surging from about 600-1250. Like if I get gas and crank it back up, it wanders for about 5-10 seconds and then calms back down to about 900 rpm where I have it set. There is also sometimes a slight hesitation (hic-up) on initial acceleration. The fuel Haynes says, there should be continuity 0. 83 633CSI Idle Surging when warm Hi Guys, If your fuel system is functioning properly and you still have a surging idle, it could be due to a failed ICM. When i would give it gas the acceleration would be hesitant, and would stay around the same rpm's until it leveled out and got better around 3k rpm's. Thread starter Edis_99Gsx; Start date Sep 14, 2021; This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others. k. G. 1 post • Page 1 of 1. View Profile View Forum Posts Member Join Date Aug 2009 Location charlotte NC Posts To fix the high idle, first check for any vacuum leaks, check auxiliary air valve and if those check out ok check the throttle adjustment. My truck seems to Bmw e30 idle problem. 02-0. After a couple of minutes, smooths out and idles fine. Jump to Latest 15K views 23 replies 5 participants last post by JDawg965 Dec 14, 2011. E30 (1982 - 1993) "Fixed" my idling problem: 1987 325 & it had that notorious surging/revving problem where after reaching operating temperature, the engine would rev between around 900 & 1500 RPM. The "pull the coke out and back in" trick works sometimes, but usually not. E30 Zone Team Member Posts: 4851 Joined: Tue Sep 27, 2005 10:00 pm Location: TELFORD !!!! (Shropshire) Stevetigger Land !!! M52b28 surging idle when cold. I have A 1997 f 250 2wd with 233000 miles. net Subject: [xj-s] surging idle only during warm up. Did some basic maintenance on the 325e, plugs /wires ( Bosch wr9ls) in addition to replacing the coolant temp switch as well as the thermo-time switch (blue plug for cts) ( Multiple names for different sensors so if i got any of the names wrong please educate me :) ) Car starts up great, So here is the back story. jpg - - - Updated - - - Originally Posted by NomadHooker. I replaced the coolant temp sensor and that fixed my idle, but now I have a surging idle problem. The temp guage starts to climb and when it reaches 'Normal' ( about 1/2 way ) it starts this surging at about 5 sec cycles from 1200 rpm - 1800 rpm & back. But when it gets up to operating temperature the idle will drop down and surge between 800-1500 rpm. Then it might drop to 550 for half a second then back up to 600rpm. Hi i am new to this forum but i am having serious headaches trying to solve this idle problem. I’ve replaced a good amount of parts while doing this swap but a few notable parts that aren’t changed are the distributor cap and rotor, valve cover gasket, intake boot, and testing the afm. The stalling typically occursafter the engine is fully warmed up when stopped in traffic or at a light. Our guide offers detailed troubleshooting steps for Honda idle surge issues, providing insights on resolving surging idle when warm. Explore now to keep your Honda running smoothly. If you have Alpha-N or a standalone - no harm in blocking it off and giving it a E36 M3 (1991-1999) and E30 M3 (1986-1990) . Thermostat must be open. JDawg965 Discussion starter. Idle issues, rough idle that will stall on startup. 9kOhm pins 1-3, 1. I've replaced the blue temp sensor, spark plugs and wires. i have a 98 GSX and the car runs & drives fine when its cold but once it gets to operating temp it starts idle surging and the car will die if you dont keep Yup. E30 Zone Newbie Posts: 165 Joined: Wed Feb 06, 2019 10:56 pm Location: LDN. The car is throwing no codes. Post Wed May 15, 2019 5:04 pm. I'm getting a wandering, surging idle, 750-1600rpm. A typical starting point would be 0. reddettmann Discussion starter. When something like the A/C is turned on the extra load will slow the idle down so the electrical part of the ICV opens up more flow are to speed the idle back up. Although not usually a problem, a bad DME temp sensor is a possibility. 3 posts · Joined 2023 Add to quote; Only show this user #1 · Feb 17, 2023. I'll turn the revs down before turning the engine off, and even though I just spent 4 hours at max throttle with zero issues, it starts to surge when it starts to idle. Surging Idle E30 325e 1986 07-12-2017, 11:19 PM. 3 series & 4 Series (E21, E30, E36, E46, E9x, F30, F32, F33, F36, F44) 1991 - 1999 ; BMW e36 m42 318i idle issue when warmed up; I recently got it and I am having some issues . Once it gets up to normal running temp it idles perfectly and the fuel mixture is Hey eyeryone! I have a 03 325i with the m54 (130k miles). Any help would be greatly appreciated! Attached Files Boss 302ci. Is this normal for an old car or should it stay perfectly at 800 or something? I cleaned the ICV with carb cleaner but didn’t seem to do much. That generally won't cause an unstable idle, but can cause hard cold or hard hot starts and/or a rough idle. In gear at a light or running at slow speed, all is good. m20b20 It idles steady at about 600 rpm, according to haynes manual it should be idling at 760 rpm +/- 40. Old engine had 10. payne5757 Discussion starter. I checked all vacuum lines, caps and replaced 5 of them. If the engine is cold it is fine, purrs like a kitten. When the car is cold it will idle steady at 1000 rpm for a few seconds then start surging up and down between ~500-1500 RPM. Mark Dawley · Registered. When it is put in drive it it feels that the idle speed is too Surging Idle E30 325e 1986 So this issue was there when i purchased the car. What would make the car no idle properly when its warm? 09-12-2017, 09:38 PM #2. Here in Wisconsin winter is not nice to cars. Advertisement Coins. ^start there, it is easy and free. Return to “E30 Technical Help” Jump to. 7->4,4k pins 1. Any ideas? If I pull out the dipstick or The ICV has a measured flow opening that should provide a set idle speed. This car is in showroom condition. It happens 90% of the time now. 3 series & 4 Series (E21, E30, E36, E46, E9x, F30, F32, F33, F36, F44) 2006 - 2012 (E90, E91, E92, E93) E90 N52 4,5,6 Misfire + Surging Idle Cold & Hot; E90 N52 4,5,6 Misfire + Surging Idle Cold & Hot Recently picked up a 2006 330i. Jump to Latest 7. Essentially it occasionally won’t hold idle and will stall instantly without revs. Bouncing idle when warm. I inspected the intake boot and found no cracks, no other vacuum leaks have been found. I have tested the icv and it works, and I just replaced the tps which did not help the situation at all. Let me first tell you what was done to the car. Checked fuel regulator, E30 Zone Regular Posts: 251 Joined: Wed Dec 19, 2018 8:24 pm Location: Bavaria, Germany. Surging idle is fixed! The vehicle will surge and misfire badly at idle in gear. The engine will almost die (sometimes it does) when you blip the throttle and it comes back down to idle off of deceleration. I have an erratic surging idle, the idle varies from consistent high about 1200rpm's to surging from 500 to 1200 to surging from 800 to 1800 I've noticed about four different idle patterns now. A local mechanic said the mixture seems to be too fat but had no concrete solution saying I have to live with it. The truck start and idles smooth. Engine surges to about 1500 then slowly comes down to about 1000 rmp but bounces as it does. Kyvonne10. Often it surges between 1000 - 1500 RPM, but sometimes it can just get stuck For the DME (or ICM) to control idle, the idle switch in the TPS must work correctly. there was continuity just before throttle stop when the tps switch From cold the engine idles as usual, but as it warms up the idle becomes increasingly unsteady, until it gets to the point of roughness in the video. Drove to get car up to temp and confirm closed loop operation. Once warm it won’t stall but the idle is still rough and it fluctuates under acceleration motor is an m40 in an 88 coupe if that helps. You should hear quiet buzzing sound from When you start the car, the engine looks for an IDLE signal from the switch under your throttle body. Had some misfires, but all was fixed with new Bimmerforums is the preferred online BMW Forum and community for BMW owners. 92 E36 Idle Surge - Only When Warm92 E36 single vanos, 130K, good compression and rebuilt head. E320 Cabriolet 1994 surging idle when warm. It does it all the time, but you only feel/hear it at idle. 1998 528i. 5:1 compression and for whatever reason had to have 17. The engine starts fine when cold and idles steady (about 900-1000 RPM), but when it warms up it surges from 1000-1400 in a very steady pattern. will a local tuner on this. But I think a too fat mixture kills the catalytic converter over time. Jump to Latest 21 - 40 of 48 Posts. Your idle ignition is also a bit more advanced than I would use for E-throttle. zip (418. My issue is specifically once the engine is warm when the mower is in neutral. After it has warmed up the engine begins a surging idle, approx. Discussion starter · #21 · Aug 25, 2022. 5° of timing to run. I had some low idle issues over the winter, which were chased off by a new-ish FPR and replacement CTS (an imports direct model). I know there is tons of info out there about surging idle and what notbut nothing ive read has helped me so Car idles fine, but very high when cold around 1100rpms when car is hot/optimal temp the idle is the same but keep on jumping to 1300 and down to the regular idle (1100) no vacuum leak, sprayed the entire engine bay with start gas, everything is brand new, o2 sensor, coil packs, plugs, afm, gaskets, dme, fuel filter, icv E30 Technical like others said, first thing to try is simply turning the air screw. 05 for e-throttle idle so confirm you are around that, if not then try 0. 4. It does this under a specific set of conditions, and it takes a while to replicate. Car has a bit of a long crank, once it fires it runs perfectly for 1 to 2 minutes. I have been trying to figure this issue out for the past week and I need some help. 6 mm from throttle stop and when throttle switch is within 8-12 degrees of fully open. When 34K subscribers in the E30 community. If that switch is fine (i. (I had surging idle every once in a The idling issue really only comes up when the car is at full operating temp, and when it's not under load. E30 1986 325E Surging Idle, poor acceleration So this issue was there when i purchased the car. Post by concept_R » Thu May 10, 2018 5:27 am. Post Sat Apr 30, 2016 12:10 pm. e34 530 Posts: 761 Joined: Oct 27, 2007 7:19 PM. had a lower rpm then normal then it when up to the normal idle. 0skylineeater Jul 1, 2011. The motor would start and then surge upto around 3000 RPM and would stay there until the engine would warm up where the car would idle steadily at about 1500RPM. Save Share its every other second it is surging up and down when i'm idling at a lightit didn't do that before . Members' ↳ New Members' General E30; ↳ E30 BMW Chat; ↳ E30 Builds / Restorations Discover comprehensive solutions to your 'Honda idle surge when warm' problem. 1113 posts · Joined 2006 Add to quote; Only show this user #1 · Dec 17, 2008. So this issue was there when i purchased the car. Make sure your bike is very good and hot before setting it, not "oh I let it idle on the stand for 10 minutes, it is hot" If you do it this way when you ride the bike hard and it gets truly warm the issue will return. I'm assuming it's a lean surge hunting for more fuel once the cold start is finished working. You may have to register before you can post: click the register link above to proceed. 11 posts · Joined 2019 Add to quote; Only show this user #4 E30 Zone Regular Posts: 532 Joined: Thu May 16, 2019 6:43 pm Location: Bristol. First i will list the symptoms and then the work that has been carried out. Once warm, as soon as I move the control levels to center or open them to neutral, the engine beings surging. 88 M6, 86 535i, some e30's and 72 02 in pieces. No The engine also works very well under throttle hot or cold. Jump to Latest 699 views 1 reply 2 participants last post by JimLev Feb 23, 2023. I’ve given the ICV a good clean and at first it seemed like it fixed the problem, but I think it was just coincidental as it came back a day later (Air BMW e30 1989 Convertible Automatic I've been searching all over the internet and I'm just running around in circles. Need technical Q/A then you're in the right place. The A common glitch on the BMW E30 3 Series is erratic engine idle constantly surging between 800 and 1800 RPM. I experience no loss of power when driving, and no idle surging for the first 15 minutes of driving typically. Premium Powerups Explore Gaming. Following these steps may allow you to diagnose the the yellow coolant temp sender - bypass it altogether, the switch is likely burned out and the engine never thinks it's warm, so it hunts for idle above 20c. E30 Addict. It will bog and misfire under load when you attempt to hold the throttle and even sometimes stall. e. Jump to Latest Runs great off idle with excellent drivability except for warm idle. However, once the engine warms up to operating temp it starts to surge only at idle from 600 to 1200 rpm. My father took my E30 this winter to drive as his DD. in the meantime, still getting the P1404 code almost constantly, normally when downshifting ( t-56 tranny ), but occasionally with steadily cruising on the freeway. It only seems to happen when coming to a stop. I have cleaned and adjusted the FITV, cleaned the IACV, replaced ALL vacuum hoses, replaced all intake manifold gaskets, made sure TPS is properly set, no air in coolant system, and made sure that the car has properly learned the idle. It occurs approx 90% of the time, the other ten percent it idles about 1000. My '90 E30 with the six cylinder M20 engine idles unevenly, especially when the engine is cold. Idle overall is out of wack and hardly ever stays in one spot. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. Our professionals are here to help make sure you find the answers you need to your questions and Surging Idle/Stalling when warm. Jump to Latest 44K views 9 replies 3 participants last post by RadarRider Jan 2, 2009. M52b28 surging idle when cold. TPS gets 3. Surging from 800-2000 and then back down repeatedly. when ever I start it it hunts for about 15 seconds then idles smooth, be it hot or cold . I think it checked ok. So far I've changed I've fitted a new air flow meter and cleaned the idle Air control valve which seemed to sort it at first but only took a short drive and didn't allow time to warm up. New FPR and steady needle! Surging at idle and on warm start. I recently bought a e30 and my engine will surge on idle when around 800 rpm, high idle runs smoothly, the surge is only around 50-100 and I wanted to know what would cause a surging idle at only a certain rpm. When I first start the car it idles and warms up like normal. Drives fine, idles fine - purrs - while warming up but will start to surge when warm and out of gear. Following these steps may allow you to diagnose the fault a lot quicker than I did with my BMW 325e. 020-0. Occasionally it will drop to 750 and idle normally. Members' ↳ New Members' General E30; ↳ E30 BMW Chat; ↳ E30 Builds / Restorations since the youngest E30 is going on 19 years old, if the ignition system is original or the plugs are old replacement is indicated. I THINK the ICV is open when unplugged, closed under power. I decided that my issue had something to do with my coil so i replaced it, that obviously didn't E30 Technical Forums; Engine & Drivetrain; M20; If this is your first visit, be sure to check out the FAQ by clicking the link above. like an air leak E30 on Microsquirt Idle surging. 128 posts · Joined 2005 Add to quote; Only show this user #1 · Dec 1, 2011. decided to try adjusting the Idle Air Stabalizer Valve screw (remembering where & how much I was turning) & I found that with 2 My 325es m20b27 idles very erratically. If I hit the gas pedal the Check Engine Light disappears and the idle levels up for a short time. And I've confirmed the injectors aren't leaking or sticking. I disconnected the Idle Control Valve and it seems to help a little. I have no issues on cold starts, and no issues on hot starts. It ONLY happens after 20 minutes of drive time in gear and is fine when given any throttle. Share Add a Comment. It idles fine until about 150°, and then it starts surging so bad that you can't even figure out which fuel cells it's on to take E30 Cold Start Idle Issue I've been having this cold start idle issue for at least a year or more. Perfect when cold. When I got it there were some issues, but nothing too crazy. 5K views 7 replies 6 participants last post by 5. At that time the Check Engine Light comes on. It will drop to well below 500 revs then surge up to nearly 1800 revs and continue bouncing back and forth until I get back on throttle if it doesn't stall in the mean time. With the cruise on rolling at 65, I can see the needle surge. Start with idle ign target at 10, min clamp at Hi im new here. I decided that my issue had something to do with my coil so i replaced it, that obviously didn't help. 1 2 3. Moderator: martauto. 1990 320i. So by unplugging it I'm letting in more air (I think!). Post Unplugging the CTS should cause the idle to increase but if you try to drive it warm it will Once it began to warmed up I could feel a light surging at tip in that progressively worsened as it continued to warm up. The ONLY issue I am having is that the idle is surging when it's warmed up. Would Love: E30 M3 or E34 M5. I didn't have this issue until recently (I noticed it a few days ago). The most likely guilty party is your ICV, as other have mentioned, best case scenario is that it’s just dirty and a good cleaning will have you smoothed out. The engine will surge a bit before catching idle. It happens both when cold or warm, however it only occasionally happens and goes away after a few minutes. The car is all stock, except the E36 TPS, a 3bar GM MAP, and LC-2 O2 sensor. Symptoms: car starts fine and seems to idle fine until temperature gauge gets to between 1/4 and half way, then idle becomes erratic, kind of surging although the needle on rev counter is dead steady, when 87 E30 M3 Prodrive British Touring Car 88 E30 M3 Zinnoberot - Street 88 E30 M3 Lachsilber - Race (#98 SCCA SPU) (1100 - 1200) and can run a cold enrich / cold advance programs to help get the car running. Only show this user Hey guys, I am curious here if anyone knows if low transmission fluid could possibly cause the engine to stall. During a cold start the engine up should have a faster idle which should be controlled by the signal to the ICV. It dose it most of the time but every Hey guys Just bought my 87 325is and ive got a weird surging idle problem. If I unplug the ICV the warm idle is perfect at 800rpm! I've cleaned the ICV and it seems fine. After running for about 10-15 mins - when the radiator is hot and fan comes on I've been having this problem for a month or two now where the car will start up and drive fine idling at about 1500rpm cold. Is the mixture being fat the only reason for an uneven idle? Surging idle when warm. I have had a surging idle problem when coming to a stop. Date: Thu, 15 Jul 2004 05:34:54 +0200 From: “Ken Eakland” eaklandk@comcast. Also just had the car in for a new timing belt/water pump, drove about 50-75 miles since that has been replaced, and it was A few weeks ago i put a new battery on an started it up but it was surging on idle, revving beetween 1k and 2k revs constantly, but would rev up fine when applying the throttle. Rough Idle/misfire When Warm 325i Jump to Latest 13K views 12 replies 5 participants last post by 3serbmdubya Mar 25, 2005 high & surging idle i'm trying to set up an appt. Went back and looked for a vacuum leak (3X) but all looks good. Once replicated, it won't stop until it's cooled off. Jump to Latest The other day the car has started surging on me on a warm start. The problem got worse after I got the water pump along with some other belts replaced by a mechanic. It idles around 600rpm when warm by looking at gauge. the idle control Any extra air that's getting in must be after the throttle butterfly to increase the idle speed. 0L Auto Gray 2015 Nissan Frontier S Auto 4x2 Black Set your base warm idle to 750, without A/C, and if you still have the problem when A/C comes on, screw in the A/C idle 1985 e30 325e unexplained surging idle. Oddly enough, when I bought the car and test drove it over the course of two days, I never saw this issue come up. 7 Surging Idle when warm and Stall. ir getting in before the butterfly will upset the fuel mixture, which can only reduce idle, I have a BMW E30 325i from 1987 that has a problem with surging idle that only happens when the car is warm. Our professionals are here to help make sure you find the answers you need to your questions and the idle increases up to 1600rpm when the car is on P or N (after a few second on stationary) it happens only when the engine is warm; No engine warning lights; The car works perfectly the rest of the time. Join Date: May 2004; Posts: boot in between the afm and tb and the car fired right up. Also, it has started a light surge at traffic lights or while waiting at the drive thru View community ranking In the Top 5% of largest communities on Reddit In the Top 5% of largest communities on Reddit Hunts for idle, varying rpm from ~500 to ~800 and will find a steady idle after ~15-30 oscillations, sometimes starts the hunt over again afterward; Only happens in Park or Neutral, never happens in Drive or Reverse; Only happens once it's warmed up (closed loop), seems to get worse the warmer it gets The idle go up and down from almost stalling to 2000 RPM or so. Need technical Q/A then you're in the right place fine when warm. The plethora of things I tried to solve it: A common glitch on the BMW E30 3 Series is erratic engine idle constantly surging between 800 and 1800 RPM. Joined Aug 28, 2019 · 101 Posts. E30, E36, E46, E9x, F30, F32, F33, F36, F44) 1975 - 1983 (E21) 1983 - 1991 (E30) 1991 - 1999 (E36) 1999 - 2006 (E46) Today's Posts; Member List; Calendar; Forum; E30 Technical Forums; Engine & Drivetrain; M20; If this is your first visit, be sure to check out the FAQ by clicking the link above. I bought from the off-lease buyer who owned it since 1988. Here's what I get: Pin 2 (middle) to Pin 3: Pin 2 to Pin 1 Pin 2 to earth / ground So, according to the sticky, there is either something wrong with the ECU, or the wiring harness - and I've ruled the wiring out as I have continuity from pin 1 and pin 3 on the ICV plug to the correct pins on the ECU plug. The idle eventually levels out or gets worse and stalls. 0 coins. It goes on for about 30 seconds or so and then it levels up for a while. Jump to Latest and that was the issue with my surging idle! It only would surge when the engine was warm and in park! Save Share Reply Quote Like. which is the intake timing slipping from the nominal angle causing a rough idle when warm. O. It's only after it's been run, then allowed to cool for 15-20 minutes. This started very suddenly a couple days ago when I came to a stop sign mid-drive, on a warm engine. I built a Microsquirt module for my E30. My 92 XJS has developed a surge in the idle during Posted by u/hpbt1973 - 6 votes and 2 comments I’m working on an M30 swap for my E30 and ever since I’ve got the engine started it’s had this problem. I live in the desert so the engine is usually nice and warm even Again, my issue is surging idle when the engine is warm. My previous idle was only 750 or so and very stable My secondary o2s are bad but were bad before my other issues. 15 posts • Page 1 of 1. Once it nears operating temps the idle becomes erratic getting worse as the car gets warmer. xvuczuynftxhpvutlsaexufrsogkmvqdxybcucbgjyjcfglmrqdmwvvczdqwxhwoyqogoyew