Engine stalls intermittently on braking.

Audessy · Post by **Audessy** » September 29th, 2007, 6:43 pm

For some reason I've had this problem with my K8 for like 5 years and now the problem transferred over to my KLZE. Only now it's a little worse. The K8 never stalled unless I had the idle below 800 rpms. The KLZE will stall every now and then if I'm doing the daily city driving and I push in the clutch and brake at the same time. Sometimes it stalls, other times the rpms bounce below the bottom line and 1100 in quick oscillations until I let off the brake. Any ideas?

wytbishop · Post by **wytbishop** » September 29th, 2007, 7:27 pm

If your PCV valve is stuck closed, when you use the brake, and a lot of vacuum in the process, the manifild pressure goes down and it will try to equalize throught the PCV system. If it's plugged you could stall. Mine was stuck open. my stock K8 would surge badly when I held the brake because it was taking too much air and the ECU would deliver extra fuel to compensate. I changed the PCV valve ($11) and it went away.

There are many vast and exhaustive discussions regarding the various idle issues common to MX3's. You will likely get a lecture at some point very soon regarding the search function and doing a little research...of course I'm not going to do that...but someone probably will very soon.

Audessy · Post by **Audessy** » September 29th, 2007, 8:07 pm

I tried a new pcv valve and it didn't work.

No, I'm not new to forums. The search feature brings up all sorts of crap I don't need, but I do use it every time. I just won't spend 30 minutes trying to find an answer to my question only to find there isn't an issue on the forum that is my EXACT issue. FYI I do use the search tools like AND and OR.

I could look through 50 topics on setting the tps but that would be a little nonconstructive wouldn't it?

wytbishop · Post by **wytbishop** » September 30th, 2007, 3:10 am

Boolean operators are tricky. I prefer the brute force method.

If you check a few of the "idle trouble" threads, you'll find that the general consensus is to start by checking for leaks in intake hose, vacuum hoses etc., then TPS calibration and then on to the miriad other sensors that cause this sort of thing. I'm really not an expert. This is just what I've read.

The online manual has a pretty good step by step troubleshooting page.

Audessy · Post by **Audessy** » September 30th, 2007, 3:18 am

I haven't calibrated the TPS but I'm positive it was okay before I did the swap. I'm using the old throttle body on this engine as well. I highly doubt that the vacuum leak I could be experiencing was on the old engine too. I'm sure it's possible but I checked them over and over and over again and it all looks okay.

Audessy · Post by **Audessy** » October 18th, 2007, 11:47 am

Okay, I switched to the new TB. I have the idle pulsing crap from time to time but I think that's because of the old K8 ecu. I have it under control for the most part.

The big issue for now is that after I rev the engine the idle falls fast and dips down to 100-250 rpms. The lights usually dim for a sec like the car is going to stall and then it jumps back up again. Makes it a pain in the arse in heavy traffic. If anyone has any pointers please let me know. By the way this problem somehow transferred over in the swap. I've had this problem with the K8 since I got it in 2003.

Trevor · Post by **Trevor** » October 18th, 2007, 12:12 pm

Set your Base Timming and Idle to spec. Then do a TPS adjustment and that should take care of your issues. Also make sure there is no air in your cooling system.

ninjajim4 · Post by **ninjajim4** » October 18th, 2007, 1:18 pm

good advice from trevor.

first off your premise is totally wrong. you can't take a TB and stick it on a completely different motor and expect it to be calibrated right. second, if you had this issue with your K8, and now it's there on your new engine, then clearly there's a good chance you brought it along with you. why should you have the exact same problem on a completely different motor? not saying that's not possible, but i mean, go with the odds. what did you bring with off your old engine? your throttle body. what's on your throttle body? your TPS.

how ironic that you're unhappy with all the TPS hits you got, and that's probably what your problem is. why ppl think they shouldn't have to spend 30 minutes of their OWN time to fix their OWN problem is beyond me. why should they waste their own time when they can jsut have someone else waste theirs answering the same questions a 1000x.

this isn't to say we're not a community and we're not all here to help each other -- but courtesy should come in both directions.

Audessy · Post by **Audessy** » October 19th, 2007, 12:35 pm

Wow, you know it's usually up to the forum moderators to bite people's heads off about searching forums. No to mention the search feature is an antiquated boolean system. I HAVE tried searching this problem on probe talk and here on mx-3 and found similar with the pulsing, but not with the near engine stalls after a rev.

I posted just before Trevor that I AM using the correct TB now. I have adjusted the TPS. I have burped the cooling system as much as I possibly could. My issue isn't necessarily with the pulsing. I've learned from yes... using the lovely search feature that sometimes it just isn't fixable with a k8 ecu. My problem is something that boggles the minds of mechanic friends of mine who have been working on imports and domestics for over 10 years full time. The car drops to about 100 rpm, the lights dim and then it picks back up to 800-1k like nothing happened after a second or 2. We're starting to wonder if it's a ground issue, alternator, or possibly the distributor.

wytbishop · Post by **wytbishop** » October 19th, 2007, 12:49 pm

Grounding is a real possiblity. I would try that next in your position. It's not expensive or difficult and even if it doesn't solve your issue it is a worthwhile upgrade.

shameem · Post by **shameem** » October 19th, 2007, 3:56 pm

Disconnect all the brake lights (or pull the fuse) and see if the problem still exists - that may give you an idea about how to proceed.

DO NOT DRIVE WITH THE BRAKE LIGHTS DISCONNECTED -I shouldnt have to say this - but you would be surprised at how many times i have encountered people that dont have the common sense to take precautions or follow proper procedure.

Audessy · Post by **Audessy** » October 19th, 2007, 8:01 pm

Lol, or like me. Drove for a while without front turn signals. Really allows for some cussing from other drivers. Even better, I hooked up fog lights as turn signals for a while. I love getting a rise out of people.

Yeah, I'll try the ground. If not, I found a awesome ZE vacuum system diagram on mx-6.com. I'm going to go through it all with a fine tooth comb, just incase I missed something the first 50 times. I don't know if you guys have seen it but check it out. It's the reply that "xbob" did.

http://www.mx6.com/forums/2g-mx6-other- ... e-faq.html

Audessy · Post by **Audessy** » October 20th, 2007, 2:20 am

Guys... I hate to say it... But I think it was a jammed thermostat. My engine never overheated since I did the swap so there wasn't a tell tale sign there. However I found this out on accident. The engine was pretty toasty but the radiator was cold. I pulled the thermo out and threw it into some boiling water. The thing would only open half way at 220 F. Somehow the top of the thermostat was dented. I have clue how that could've happened.

My timing is off too. I really hope this topic can help others with this problem. I haven't changed the thermostat yet but I'll find out tomorrow when I buy a new one. Thanks again everyone.

Audessy · Post by **Audessy** » October 22nd, 2007, 1:37 am

K, the timing is perfect now. The thermostat is new and tested personally. Still have the same problem. Only thing I can think of now is the ECU, Fuel pump, or distributor.

shameem · Post by **shameem** » October 22nd, 2007, 11:38 am

You have disregarded all the advice people gave - you refuse to search - i dont know what to tell you man - other than good luck with your problem.