Cold Start Issue: Wont hold idle after ~30sec SOLVED

[2mAn]

I havent done either of those things. The AFM looks brand new and the ICV was cleaned.

Since the injector change, the car hasnt had the issue at all.

Edit: No reason to bump the thread...

Car was parked for a week while I was out of town. Came home and it fired up no problem. Im confident that the sensors helped but ultimately the issue was the nasty injectors.

Start with the basics!

[paynemw]

Weird, I had my injectors cleaned and bench tested and now I'm having a similar issue with low idle and dying. It sounds like you might have solved it. However, have you bench tested your AFM to ensure you have resistance throughout the duration of the door opening? Have you bench tested your ICV per Bentley and in the car? The pulse sensor (aka CPS) is typically fine unless your idle is crazy. and you can test it, you also need to make sure it's gapped correctly. Your TPS will cause erratic idle, and you'll need to test it before you pull your throttle body, then you need to make sure your throttle plate is set to spec with the set screw set properly, then you have to set your TPS properly for idle, then non-idle, then 10* from WOT.

I'm going through an idle-ing issue and a check engine light (with originally auto M1.1 with 173 DME that doesn't show codes during a stomp test...) and I've learned ALOT from all of these sensors

Another thing to know about M1.3 harness. The C191 connection for the fuel rail becomes loose (the female side doesn't squeeze the male side like it should - so continuity isn't ideal) which causes a big issue with M1.3 M20b25s that typically become overlooked. I suspect I have a harness issue.

[hippiester]

Fuel pump relay or main relay? Mind did a similar thing a ciuole tears back

[2mAn]

Wanted to update this because Im about ready to say the problem is solved....

The issue had become more and more intermittent, but it was still there. It basically became a once a week issue or so. More and more I suspected the injectors. My mechanic had the car for about a week and said the issue only popped up once and then it started right after it died. My mind was telling me that there wasnt enough fuel and once the car switched the "cold start mode" off and likely trimmed down the fuel supply it wasnt enough to keep it going.

With this in mind, I decided to charge forward with the 19# injectors (rebuilt set bought from Bimmer_Baron) and a Sssquid chip tuned for 91octane and the injectors.

2 steps forward... by 2mAn

Ignoring the issues with installation and all that fun stuff I dealt with, when the injectors were out, they were VERY dirty. Granted part of that was from the removal process and the dirty area they were in, but a few of the injectors were still so nasty even after trying to clean them.

2 steps forward... by 2mAn

2 steps forward... by 2mAn

Its been a week since the install and I havent had any issues with the car dying. I will report back in a few weeks again to confirm, but for now it seems the injectors were the biggest issue, but replacing the coolant temp sensor definitely helped the problem.

[SteveO]

I had an issue where the car would die within 5 seconds when it was -25c ish out no matter what I did. it would only stay alive if the engine got warm enough or I heated up the ambient air to around 0c.

Ended up being the spark plugs were loose and were not grounding (i assume) because of the cold (I assume) and would flood out and die (I assume).

Some one else mentioned grounding so maybe not getting proper ground and a full spark causing it to die until its warmed up.

[sert57]

cable from oil pan (near oil level sensor) to chassis

[2mAn]

So its basic, but have you checked the engine ground cable? I could see it giving some of the described symptoms.

I havent, but I will check. Are you talking about the cable that goes to the motor mount arm or something?

[sert57]

So its basic, but have you checked the engine ground cable? I could see it giving some of the described symptoms.

[2mAn]

Weird thing is that since I removed the aftermarket alarm, it doesnt seem like this is a problem anymore. However, that being said and tomorrow being monday, I fully expect my week to start with some stress haha I will keep battling this until its gone.

Keep the random ideas coming.

Knew I was wrong...

Monday = no problem
Tuesday = small hiccup, but not really an issue
Wednesday = a real bitch until I got it going and held it at ~3k rpms until it was warm...

I need to figure this thing out.

[2mAn]

Smoke test to see if there are any vac leaks??

I could do that, but I think a vac leaks would be a different issue. Wont hurt to do it though. Cleaned the ICV and it seemed like it was already clean. This car keeps showing that its been well maintained. Went to change the airfilter while the ICV was drying and the filter looked new and wasnt dirty at all. The inside of the AFM also looked squeaky clean

Weird thing is that since I removed the aftermarket alarm, it doesnt seem like this is a problem anymore. However, that being said and tomorrow being monday, I fully expect my week to start with some stress haha I will keep battling this until its gone.

Keep the random ideas coming.

[Gregolas]

Smoke test to see if there are any vac leaks??

[2mAn]

I would definitely clean your ICV if I were you, I had a similar problem with my ETA. It would fire up and idle fine at first, but instead of just straight up dying, the idle would surge like crazy for a few seconds and then die. I also have a set of freshly rebuilt 19lb injectors if you're interested.

Excellent first post Sir! haha I really should clean the ICV to eliminate that as an issue, as Im sure it needs a cleaning anyways.

[Bimmer_Baron]

I would definitely clean your ICV if I were you, I had a similar problem with my ETA. It would fire up and idle fine at first, but instead of just straight up dying, the idle would surge like crazy for a few seconds and then die. I also have a set of freshly rebuilt 19lb injectors if you're interested.

[sert57]

Does it seem to run rich or lean when it starts initially?
Don't know how relevant, but on my 2.9 i had an issue with the ford injectors leaking. It made cold starts fine, but warm starts were tricky. It even died on me twice on the road.
May be relevant, but with this problem im leaning towards not.

Icv?

[2mAn]

Im going to change the CPS and also the fuel filter. I dont think either of these will solve the problem, but they are good items to replace on a car thats just about 30 years old. I will check to see if they CPS looks bad.

Im really thinking I should change the injectors too, but I want to work my way to them