I have an annoying issue

Twice in the past week, my car has shut itself off with no warning at all (and in very bad locations, like going down the road). I will try to refire it, and it will crank but not start. I try this about three times, with the same result, cranks, but won't start. I will give it a minute, and try again, and it will fire right up and drive normally.

I have no idea where to start with this because I obviously can't diagnose a problem that isn't currently happening. It has only happened twice, and I was not in a position to finger it out when it happened. I was hoping that the car would just refire, and both times it did. /ubbthreads/images/graemlins/banghead.gif

It has to be losing something because it takes approx. one full minute of cranking (spread out over several attempts) to fire again, but then it runs fine. And I mean good. No misfires, full boost, good power, Just like nothing ever happened.

My best guess is CAS and/or CAS electrical connection. If it lost the CAS it should lose both the injector timing and ignition right?

I am hoping someone else has experienced this and can provide some input.

I do have another CAS, a black top that is untested from a junkyard car, that I can swap. I need to get a new timing light first because I "broke" mine. The only problem with doing this, that I can see, is that I won't really know if I fixed anything. The car runs fine right now. I drove it to work this morning. /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/bawling.gif

 

[Terry Posten]

Caps been changed?

Is the fuel pump running after if dies?

 

[stealthtt24]

Interesting, I'm thinking it's fuel related. Were you low or best low on gas? Talking to myself here but I wonder if pumps can start to go bad.

 

[89Mirageman]

There was a guy on the mirage board that had a similar problem a while back and it ended up being the power transistor unit. Not saying this is your problem but they are easy to find at the junkyard and not hard to swap out. It would be something to eliminate if norhing else.

 

Yes the caps have been changed. The second time it was pretty low on fuel. Just below a quarter tank. I do have another Power Transistor unit that I can try.

 

[galantrevolution]

have you done a fuel pressure test? maybe the fuel pump is going bad, and try to do the test before the filter and after the filter.

 

The fuel filter is brand new. Less than 4000 miles on it. And my car has always been a driver, it is extremely unlikely that any gas has ever sat long enough to create an issue in the tank. The fuel pressure is at 35 psi at hot idle with all of the vacuum lines still hooked up. I think that I'll bump it up a couple pounds, as I do have an adjustable regulator.

 

[BluFalcon]

Is the fuel pump rewired? On my old GVR-4 I used to have a similar problem. The relay I was using was for the fuel pump rewire was faulty, and would fail intermittently and shut the car down. The car would start again after a short period of time. Might be the same thing.

 

[toybreaker]

Next time it flames out, check it for spark.







































... just grab a plug wire with one hand and a good ground with one the other, and have a passerby crank things over for ya.













Report back on how that works out. /ubbthreads/images/graemlins/grin.gif

 

Been there done that.










On a Heep YJ with MSD ignition.



Popped the hood and held it up with one hand while pulling the coil wire off with the other. Yeah it was running.





Dropped me to my knees and smashed my hand between the hood and the radiator support. Took me a minute to catch my breath, and a few to be able to walk on my own. I had to have someone else drive me home.






BEEN THERE, DONE THAT.

 

[TurboDSM]

Quoting toybreaker:
Next time it flames out, check it for spark.







































... just grab a plug wire with one hand and a good ground with one the other, and have a passerby crank things over for ya.













Report back on how that works out. /ubbthreads/images/graemlins/grin.gif


/ubbthreads/images/graemlins/rofl.gif

 

[mitsuturbo]

I once had a part of my wiring harness that wasn't bolted down properly behind the intake manifold rub through in some location and ground out. It would cause the car to die, and not want to start. Things would cool off a little, and it would start working again. It didn't take me long to find the problem, but it did happen 3-4 times before i went looking THOROUGHLY and found the issue.

Old cars sometimes have mysterious issues, which aren't so mysterious once you dig deep enough, or replace the right part.

I'd start with checking for spark and fuel when this happens. Check the connection at the resistor box for the injectors, and the CAS connection as well. Sometimes it's not a bad idea to pull the CAS when something goes wrong. With KOEO, Pull a plug wire and spin the cas with your finger (while plugged in) if you see spark, and hear injectors clicking, then it's probably a fuel delivery problem.

If you're not getting spark/injector activity, make sure your main MPI relay isn't kicking off. I know the 3kgtvr4 is notorious for a problem with these. Not so much the dsm/gvr4, but i've seen them go intermittently.

 

Ok, topic revival in progress....



The car has been driving without stalling since those two occurrences, until the last five drive cycles. It died 4 of the 5 times. In each of these most recent events, the car wasn't fully warm, and I was driving it very delicately. I estimate that each event was within 1/4 mile of the starting location, and I definitely am not getting fuel pressure. The pump does not seem to be recieving power either, although I have not actually confirmed this. I don't hear it running, although trying to crank the car and listen for the pump while sitting on the side of the road worrying if I'm about to be rearended by morning rush hour traffic doesn't help.

The B.S. of it is that I can't get this to occur more than once a day, and the few times that it has occured when I was actually in a safe enough location to try and figure it out, it restarts before I can get even remotely close to narrowing anything down. Atleast I know it will come back around after a couple minutes and I will be able to go about my merry way, but what happens when it doesn't?

Maybe that is what I'll have to wait for, that way the failure will be constant for long enough that I can finally fix it...

 

Quoting BluFalcon:
Is the fuel pump rewired? On my old GVR-4 I used to have a similar problem. The relay I was using was for the fuel pump rewire was faulty, and would fail intermittently and shut the car down. The car would start again after a short period of time. Might be the same thing.



I'm beginning to wonder if this is the case, although it seems less like intermittent and more like once a day in the morning less than a 1/4 mile from the house.

 

So I thought far enough ahead this morning and brought my noid lights and spark tester along for the ride. Like clockwork, she died again, and I was able to finger out that I am getting spark and injector pulse. So i definitely have a problem in the fuel delivery department.

The easiest thing to replace is going to be the 30 amp relay that I added during the rewire. Of course, the pump could be the culprit, as well as the MPI relay, and the wiring itself (although I'm leaning away from wiring due to the fact that I never have to jiggle any wires to get this thing to start again).