Hello everyone,

I have a 2000 with 52k miles which I inherited from my Mother-in-law. A year ago I had to jump 12V to the MAF due to a broken circuit trouble code, it solved that. I just ran a separate ground to the MAF also after reading here it could matter. Car has had stalling problems for a long time, at idle or coasting to a stop. Parts I have replaced recently are: IACV, Hitachi MAF, crank sensor, cam sensor, harmonic pulley. Yesterday I changed the fuel pump and filter, took a long test drive and it seemed ok, today coasting down a long hill it stalled. I have also smoke tested for vacuum leaks, nothing. I have an old Snap on Scanner that gets good data and everything seems perfect. Should I throw another MAF at it? If I had a data logger would that pinpoint the problem? Thanks for any insight.

 

What's your location....sure wish I had a virgin DEK XD

Good work on everything. This one doesn't make any sense. I would say funky crank/cam not working properly at low rpm (since you replaced the obvious causes), but even if ****ty aftermarket, you'd think the symptom would be different.
And I'm guessing it starts back up like nothing is wrong?

If you want to rule out maf, I'd log the voltage and look at fuel trim. I swipe multiple every time at junkyard LOL.

 

Are the crank and cam sensors Hitachi as well? If not, they can cause issues. I'm stumped otherwise.

 

Thanks for the replies-I am in Connecticut, near the NY border.

Yes, starts up right away after stalling, though sometimes a little harder than when cold. Car has sat for months and starts first time- then dies 10 minutes later.
Crank and Cam sensors were dealer parts, didn't make any difference after changing those. When idling the MAF voltage is a steady 1.4-1.5 V. Climbs when hitting the gas to like 2.8V. Can rev pretty high with no hesitation, so the fuel is getting through then, it's just when idling it has a problem.

I have a cheap scope and noticed the 5V reference to the MAF is "dirty" I don't have enough experience to know what it should look like though. Since the 12V wire broke, the other wires may be flaky, or the 5V source coming from the computer is brain-farting. I was going to rig my own 5V with a rectifier but haven't gotten around to it. The fuel trim is almost perfect at 100.

I also put the scope on the coils, looks ok, not that i'm an expert, and I have changed the fuel pressure regulator.

What's the engine/trans worth? it's very strong, never abused.

 

I fixed my 97 SE auto stalling issue by adding an additional ground wire to the MAF ground. This fixed it for good. Since you have already done it, I would double-check the MAF harness and wires.

 

I would check the cam sensor connector for oil. I know when I had the DE engine oil got to the cam sensor connector when the O-ring got hard and wasn't sealing.

I would also check the grounding points on the engine. usually the ground for the injectors and ECU are all joined at grounding point that go to the engine wiring harness. it bolts down to the engine and has a bunch of small wires like what I have pictured below. i have an 02 so I'm not sure if it's in the same location...

 

All the grounds are good, engine doesn't leak anything. I opened up the IACV and it's clean, then I was able to control the IACV with the Snap On scanner and relearn the idle after
my screwing around messed it up. I also checked for AC "ripple voltage"- only 22 MV so another dead end.

I am going to focus on checking ALL the wires to the all of the sensors and if those are good, replace the ECM with a used unit. (I will have the dealer relearn the keys)

 

check for coolant leaks. air in the cooling system can make the car run real rich to the point where it stalls and has a hard time restarting. i would even change the ECT connector.

I've seen where the factory hose clamps can hold under pressure and leak as the engine cools..

 

Don't pay those ****ing scammer pieces of ****. Takes 30 seconds to do yourself. Although, no reason to do it, anyway.
(I sent PM)

 

Yea the ECM is probably ok. Although it would be nice to rule it out 100%.
I saw a lot of distortion on the TPS signal, what's normal? I have no idea. it's only $45 to replace, arrives today...See what happens.....

 

My dad had a '00, and when it was only a few years old the problematic original coil packs failed and the car would stall. You don't hear about this much anymore because any of these cars still on the road have almost for sure had them replaced by now. I doubt too many would agree because normally you only get 1 or 2 failing at a time, but given what you've already checked, I would put my money on coil packs solving your problem. I bet they're the original ones given your mileage.

 

It'll run 3 cylinders down, though.

 

I've only ever been down 2, but I don't doubt that it'll go on 3.

I know what I suggested sounds crazy, and I wouldn't even think it in most situations, but with that low of mileage and being a 2000 I think it's worth looking into. If they're the original 2000 coil packs that came with the car, they were a known problem from the get-go. There was even a TSB (I think NTB01059) about it that led to a lot of free replacements when these were new. I know the symptoms don't line up with what we know after a couple decades of coil packs going bad, but it does match up with what could happen back then with the originals. No SES, nothing else needing to be replaced, just bad from the factory coil packs causing stalling.

I could well be wrong, just seems like it could line up given what's already been checked out.