I did a search, but found nothing that hit this one head-on.

My wife was driving the car (91 TA w/305) and it hesitated. She let off the gas, then it backfired when she gave it gas again. She pulled over, shut it off, and it would not start again.

The motor turns, and I can hear the fuel pump initializing. But it won't catch.

Could it have jumped timing? Is there anything in particular I should do at this point to diagnose this? I know it's a very broad problem, so I am open to any suggestions (including not letting the wife drive the car again...lol).

Thanks guys!

 

Check for engine codes. Try giving it starting fluid. Check the spark plugs to see if they're fouled. Could be a lot of things, but those will give you some idea on how to narrow it down.

 

If you hear the pump running, I'd suggest looking at things other than fuel. It's possible that the pump would run but not pump, but that would be a pretty unusual failure mode for just suddenly dying while driving down the street. Although, you can shoot some starting fluid in it, and see what happens; it won't hurt anything; it's just probably a waste of time.

I'd suspect the ignition module, or the timing chain.

The module is cheap and easy to swap. You can troubleshoot that by simple substitution.

If the timing chain (the cam gear actually) is bad, usually the slack in the chain that goes with that failure, will have caused the chain to wear a hole in the bottom pass side of the timing cover, behind the balancer. You can plainly see that spot from underneath.

Resist the temptation to start twiddling with the ignition timing by yanking and twisting on the distributor. The ignition timing didn't just suddenly up and jump off into the ozone all by itself while driving soen the street; so don't just start dinking with it, because that's not going to fix it. You'll only be creating yourself more work, since you'll have to undo whatever "adjustment" you apply to it. Leave it alone since it's absolutely certain that it's not the problem.

 

yep sounds to me like a timing chain or module or coil ...

 

Got the module; I'll let you guys know if that works. Would the module have caused a backfire, or should I also be trying to figure out the cause of that?

 

If it stalled the backfire is probably related. Just replace the module and if it starts and doesn't backfire anymore I wouldn't worry about it. You may still want to check your spark plugs, a failed module can cause them to foul and then it might not start even if that was the problem.

 

Replaced module...still won't start. The old one was in bad shape, though, so it's a good thing that it's gone, I suppose.

Climbed underneath and see no damage to the timing cover.

Other ideas? I'll check plugs next, as suggested.

 

I may have found the culprit.

What is this? The wire was melted off of it the connection with the purple protector, right next to the spark plug that is furthest to the rear on the passenger side, directly above the starter.

Ideas?

 

It's the ESC...and that would explain it, wouldn't it?

 

That's the fan switch.

Doubt it has much to do with it.

Take the dist cap off, and bump the engine over with the starter until the timing mark is straight up; and note where the rotor is. Then whirl it over with the starter for about 5 seconds, stop, and bump it until the timing mark is up again. See if the rotor comes out to either the exact same place, or exactly 180° away from there; or if it's someplace randomly entirely else.

 

The fact that the pump came on when the motor was cranked means that the module wasnt the cause since the computer was still getting reference pulses.

EDIT: looks like RB beat me to the rest of it

 

I'll try that in the morning.

I was pretty sure that that plug was the ESC, since the shop manual shows the fan switch a little further back. Thanks for the correct ID.

For now, I replaced the ignition module and all of the spark plugs (the old ones were worn enough to have gaps of between .43 and .48 - way off). We checked for spark, and are getting it. So we're getting gas and spark...but still no start.

She now turns over and catches, like she wants to start, but won't. I'm not sure where else to go, but I will try the other suggestions in the morning. And I'm still open to any other ideas.

Thanks for all the help.

 

Check the fuel filter and fuel pressure. Now that you can get it to start at least, the problem of rough starting may be the fuel filter. Even if that doesn't solve the problem, it can't hurt to change the fuel filter. Autozone part number FF504 in the filter aisle. They should be changed every 10-12k miles anyways

 

Changing the fuel filter and all that is certainly not a bad thing; but, I thought we were troubleshooting a "drive down the road perfect and then suddenly die" condition. A fuel filter won't do that. You'll be wasting your time, as far as getting your car to work. Concentrate on finding a problem that accounts for the failure instead of just aimlessly changing parts on a disabled car because it's good to change parts.

Kind of reminds me of when my late little brother was the service writer at a Buick dealership. So one day, a car comes in on a hook; much like yours, driving down the road just fine, suddenly died. The tech looks at it, writes it up for plugs, plug wires, module, rotor, cap, fuel filter, air filter, injector cleaning, fuel pump relay, and 2.5 hrs of diagnostic time. My brother asked what made the car stop running suddenly; the tech's reply was something to the effect of that all of that stuff was old and he would start troubleshooting it after it was all renewed. The customer went straight to the gen mgr (actually, the owner) of the dealership and let his/her feelings be known. Long story short, that was the last job that tech got assigned. They cashed him out on the spot and re-assigned the job to a more sensible tech. Turned out it was the rotor, a 5-minute job and a $5 part and a happy customer, instead of a nearly $1000 ticket with a $400 payday that the tech got to write himself a check.

Instead of the "maybe it's this, maybe it's that" road to hell, treat the situation with some logic. Remember, everything was fine, up until one critical instant, at which point something died. Your task is to identify that something, not to replace the entire car one piece at a time because you can't prove that it's good.

Air/fuel in reasonable proportion, spark at the right time, and compression. Those are the 3 magic ingredients that make an engine run. It's a pretty safe bet that only one is missing. All you have to do is figure out which one; and then you can narrow your search for the culprit down dramatically. Use logic and common sense, not a shotgun, to fix it.

 

Gotcha on that one. It seems like the air/fuel is okay, and we've verified spark (although just the presence of spark, not when it's occuring). We have not checked compression yet.

And you're right: it was a 'drive down the road and die' condition. So far, I'm only out about $50 for an ignition module and plugs. I may change the cap and rotor, but that's where the 'throw money at it until it runs' process stops.

It probably won't be until tonight, but I'll try the dizzy check mentioned above to see where it's hitting. If it's not stopping at the right spot, then what would the problem be?

Thanks again for all the help, guys!

 

It would be the timing chain & gears. A cheap, easy fix; a timing set (stock Link-Belt type, which is what I'd recommend) is about $20, you'd need a gasket set for another $10 or so, and it would be a good time to renew the water pump if it's old; and you'd need an oil change, and maybe some anitfreeze.

The dist is driven by a gear off of the cam. That gear very very rarely fails, and usually gives plenty of warning beforehand, by giving a mystery runs-like-crap problem for tens of thousands of miles. If the dist isn't moving in sync with the crank like it's supposed to, odds are that it's because the cam isn't being driven correctly, which is the function of the timing set.

It takes about 2-3 hours to swap out the timing set. "Rent" a harmonic balancer puller / installer tool when you buy your parts.

 

Did as suggested; the rotor points to the same place each time, and I tried it three times to be sure.

Replaced cap and rotor, no joy.

Going to try some starting fluid, then look into fuel pressure and fuel filter.

I am now totally pissed about this entire ordeal.

 

Where does teh rotor point?

 

I'm not even sure which cylinder it is at the moment, but it's pointing almost directly at the battery.

 

remove your oil cap..have wife crank the car...see if your valve train is moving when you are turning over the car is not then your timing chain is broken

 

Didn't we already cover being stupid in another post? If he already said the dizzy is spinning that would suggest that the cam is spinning, thus the timing chain is in one pc. Also after doing RB's test, he has concluded that it is in operable condition. Now shut up and just watch for a while eh?



Now as far as the problem. Check the fuel pressure. Also check the EGR valve and verify your rotor position on TDC on #1. Had you done any work on the car previous to this occurance? Also what color and type of spark are you getting?

 

Additionally, you never stated if you checked for codes.

 

It sounds a bit far over but not unreasonable. Take the cap and place it over the dist. and note where the terminal for the #1 cyl. is with the timing mark lined up. The rotor shoudl be pointing at or just slightly ahead that terminal (assuming the balancer is accurate). Alternativly it can also be pointing 180 degrees off. If its so then the timing set is doing what its supposed to do and theres nothing wrong there. Since it still drives teh cam the timing set is probably fine.

 

Not a bad point. Did the SES ever come on when all this happened? Although even with major failures the car will usually start and at least somewhat run. Even if the computer is nuked the redundant fuel device will allow, or should allow, the car to start. So far the only thing that wouldnt allow it to start on the ecms side, for me at least, was a dead injector driver circuit. Up and died all of a sudden and never worked in the car again.