Car just turns off

[TheAButton]

Ok, so I don't know what could be doing causing it, I'm thinking it's fuel related but then again I'm not exactly sure. So whats been happening is the car will randomly shut-off as I'm driving and then yesterday the just shut-off and now it won't start back up. I want to check my ECU and make sure nothings wrong with it like leaky capacitors and such (I don't know if it could cause this problem). Then I want to check if I'm getting fuel from the pump, but I don't know exactly how you could check that. So if anyone has any ideas or has had this problem before, your help would be greatly appreciated

 

[JAX2Ganey]

Check alternator

 

[TheAButton]

Well the car will crank just fine so I know the battery isn't dead and I just changed the alternator 3 months ago I'm starting to think maybe my fuel pump went out, but I dont wanna go buy a new pump to have it not fix my car

 

[91DSMdave]

Hey. I did some research for you and came up pretty short handed. i couldnt find any info on the leaky capacitors, but i have something that may help. If it randomly shuts off out of no where, your car is either loosing fuel or spark. Does the car start right back up after it dies? you might have a bare wire somewhere. I had a customer bring in a vehicle to votech with the same problem. ended up that his downstream o2 sensor wires rubbed bare where they were zip-tied to the body. the wires then touched and killed the car. you might have a positive in the ignition grounding itself out also. il try to find some more info for you.

 

[IceMinion]

check timing belt, give us compression numbers.

verify fuel pressure, my fuelpump became unwired because someone did a bad job installing it, same symptoms. check to make sure you are getting fuel pressure and get back to us

 

[gringo72884]

Definitely check the alternator...even though its only 3 months old it could be defective, also check and make sure you dont have a bad ground somewhere in the engine bay....a bad ground can drain your battery to the point where it wont be able to keep the car running correctly and can shut off all of a sudden

 

[Gasolinebaptism]

If you think it's fuel, there is a return line coming off the back right of the engine. Now I can't tell you exactly where it is, but if you think it's fuel then just take off the side of the line closest to the rear of the car, rut it in something to catch the fuel, and crank her up. But it doesn't sounds like a fuel thing. Possibly ignition coils though. Check for spark. and if you can get it to start up, the take a can of ether and spray all the intake pipe connections, if it idles up the ether got into the intake there, and tighten up the clamp.

 

[crusindregs]

I have a similar problem with my car too its random and intermittent but when i start up the car it will shut off after about 3 seconds of running and it doesnt make a difference weather i give it throttle or not. It just turns right off so im thinking its either something electrical or fuel and spark. If i wait some time itll startup just fine and the car runs normally it just doesnt stay running sometimes. Kinda stumped just hoping i dont get stuck somewhere.

 

[GooeyGus]

I'd put money on the ecu being the cause.

Obviously it isn't the alternator. You can unplug the alt completely and the car will still run until the battery dies.

When it dies, do you hear a clicking sound behind the radio?

 

[VitaminP]

I recently had the alternator issue on my 93...my battery and e brake light kept coming up very dim on my instrument cluster as the voltage regulator failed and my idle was noticeably lower. To check it...start ## car and disconnect ## battery as the car runs off the alternator when on...if it stays on ## alternator should be fine. I'd say start with the most obvious like ## grounds under the hood or if you think it's your fuel pump check that out too. Ignition and fuel are important...these cars can be expensive to own. It's hard to find a good mechanic...but well worth the effort. Good luck!

 

[Indian]

Do you have a turbo timer?

 

[steve]

The replies in this thread are pretty sad. How about a little less guessing and a little more questions before deciding what much be wrong.

Random stalling and problems restarting are classic ECU problems, so the first question is:

Does your CEL turn on for 5 seconds and then go off when you turn the ignition on?
If it doesn't then the ECU isn't running. You can either pull it and post pictures or continue debugging by checking the MPI and ignition fuses on the battery. (The ignition one I expect to be good because you need it to crank the car). Then you would check the MPI relay and if the ECU sees the ignition switch.

If the CEL is working like it should during bulb test, the the whole list of no-start diagnostics comes into play. Checking for fuel, compression, spark and make sure that your engine coolant temp sensor is working.

http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html

 

[colmer99]

Have you changed the fuel filter it is probly plugged up.

 

[steve]

The simple way to check for fuel is to pull the return line off the fuel pressure regulator and run a hose into a bucket, then crank the car.

I'd tell you to jumper the fuel pump test connector to the battery positive but not all 91's have the test connector. My car is one of them.

 

[TheAButton]

My compression as of a couple months ago was around 165 through and through give or take a couple psi on different pistons. I will look around for grounded out wires, but when it shuts of if I leave the clutch out it will down rev (like its running but then will rev down till it dies). I did put my own walbro 190 in so maybe there is something wrong there. I am also gonna try and get my friends timing light just to make sure I have spark, and then I'll also pull off the return line to check if i go any fuel. Ill keep you guys posted, thanks for the feed back

Ill go out right now and check my CEL cause I don't think it does come on at all and I know the E-prom I put in my car came from a parts car I had with around 240000 miles on it. It wouldn't surprise me if it was that ECU, cause I put the E-prom in right when I bought my current car, and it seemed fine for a little while but then the car started feeling like it wasn't getting the right fuel to it, like it was bogging down on fuel a little bit even if i just rolled on to the throttle. But I thought that if it was bad then the CEL would constantly be on? Thanks for the info Steve, Ill post right back after I check my car

Okay so I went down to my car and tried to start it. First thing I looked for when i turned the ignition to the on position was the CEL and it did not turn on what-so-ever. I cranked the car and it turned on idling very poorly and then died after a couple seconds. SO from what Steve is saying I guess my ECU went tits up.

 

[steve]

It only takes a half hour or so the first time to pull it and check it. The capacitors they used when they were built have a defect and they leak damaging the circuit board and it the worst cases short and burn up.

 

[TheAButton]

Ok so my problem still persists. I pulled out my ECU and it looked fine, like almost brand new, no popped caps, no corrosion on anything. For some odd reason as well I decided to un-plug my MAF-T and the car started, so I plugged the MAF-T back in and then it started with it in, which confused the hell out of me. I drove it down to the gas station and filled it up, go to start the car and then nothing, like it was back to square on again. No matter what i did it wouldn't start, so yea my car is being really lame right now

 

[crusindregs]

I'd put money on the ecu being the cause.

Obviously it isn't the alternator. You can unplug the alt completely and the car will still run until the battery dies.

When it dies, do you hear a clicking sound behind the radio?

No i didnt notice any clicking i just heard what seemed to be the fuel pump turning off im wondering if its something dealing with the pump but its difficult because this problem doesnt happen very often so if it was something really messed up the car wouldnt run fine most of the time would it? It almost seems like the Auto Shutdown Relay is kicking in but my car doesnt even have anti-theft so i dont think i have the ASR, am i right? If a coil pack was bad it would misfire in 2 cylinders and throw a code, wires are pretty fresh and plugs need to be replaced soon but i know their not causing the problem. Cant be an injector because the car would just run like crap not shut off. Fuel filter wouldnt cause it to shut down at idle. Power Transistor maybe? im not too clear if that can cause it.

 

[TheAButton]

Oh yea the CEL also never came on so I'm gonna throughly look at my fuses and relays to make sure they are in a working condition. Also what dose MPI stand for?

 

[steve]

MPI = Multiport Injection.

The fuse and relay power the fuel injection including most of the sensors, ECU and injectors. The coil and strangely the fuel pump are powered from the Ignition circuit.

Check the bulb in the cluster to make sure its install and not burned out. It's unusual to not have it light during the bulb test when you turn the key on and still have some activity from the ECU so they are suspect.

Post pictures of your ECU. I get people telling me all the time that their ECU looked great. Usually they really didn't know what to look for.

crusindregs, lets not hijack the thread while TheAButton is still trying to resolve his problems. There's enough differences between a 91 and 99 that things will get confusing.

 

[TheAButton]

Sry I haven't posted back in a while. So I checked all of my fuses and they were all good as far as it seemed, and I don't really know if those black relays go bad or how to tell if they do. Anyway I've been reading the guide to fixing no-starts and have been wondering whats happening to my car when it shuts off. NowI'm starting to think it might be my coil-pack; could a coil-pack that is going bad shut-off intermittently. Cause my car right now will actually start up and run pretty good, but I took it out a couple days ago running perfectly well and then it died at the gas station and wouldn't start up at all again

 

[2GFWDbeast]

i had the same problem with car tuning off check the power resistor next to the coil packs sometimes it comes undone

 

[GooeyGus]

My ECU really did look awesome, best one I'd ever seen.

I am fairly experienced with electronics, I checked the board over and over again and couldn't find the bad spot.

I sent it to steve, he was able to track it down and got my car running again at a good price

 

[TheAButton]

Ok so heres a picture of my ECU. Something I noticed is that it ran fine right before i pulled it out, and then after it sounded like it does when it doesn't so I'm willing to bet something is shutting it off as I'm driving. Sry the only camera I had way my phone

 

[steve]

You have an automatic?

Somebody has already worked on the ECU before. It's hard to say how well they did from that picture but I'm willing to bet it wasn't very thorough. Since it's an EPROM ECU is worth having it checked out and cleaned up.