'93 Flat out died ... help troubleshooting anyone?

Hi All,

93 TBI 5.7 here ... Pulling into the carport and it just went dead. Smelled gas, didn't restart at all. Let it cool for awhile, put some starter fluid in and it kicked over a few times, actually ran briefly, then dead again. Seems to kick over with starter fluid.

So I'm thinking fuel pump / filter ... but why should it smell like gas when it doesn't start? Any thoughts on this one?

Thanks for the help. I'm going to go push it back into the carport, poor old TBI.

can you hear the fuel pump when you turn the key on?

why does everybody reach for a can of quick start everytime an engine won't start?      

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I heard it once, kind of faint sounding but I don't think it's ever been that loud. The whole thing has me confused.

Anything called 'start ya bastard' must be a good idea, right? I should find some of that.

If a fuel pump fails in the garage,. will anybody hear it?

phantom 309 wrote:

If a fuel pump fails in the garage,. will anybody hear it?

Well, I want to be angry at the car, but that's still kind of funny

It is virtually impossible to check the fuel pressure on a TBI engine. If you can get the hard lines off of a 91-92 FW with an LO3/5, it has a Schrader valve port. The line from a 93 FW also has a Schrader valve port. The 93 lines are a little differently shaped, but will fit perfectly.

I would also check the ground at the thermostat housing. Make sure the bolt/stud makes good electrical contact with the intake manifold. The ground is for the computer, and the O2 sensor. My 91 ran really rich when the ground was not making good contact.

As a last resort, another area you can check is the wiring under the front of the engine. That often becomes one mass of melted insulation and wires. It is a real headache to repair in the car.

Your best bet would be to check for pump operation. If the pump is working, then check the ground. The pump has a straight hose between it and the sender unit, and if it breaks or is deteriorated, it can cause the engine to quit. If it is broken, replace the pump with a new AC Delco or Delphi pump while you have it apart. I fixed the hose and the original pump died a month later...I replaced it with an off brand pump, and it failed 30 days after that. I hate doing things over in a short period of time.

A lot of the wiring insulation near the engine becomes extremely brittle, so, be careful flexing the wires.

Your problem is universal to the engine, so look at common parts.

BTW, if the fuel pump fails in the garage, no one will hear it. In fact, no matter where it fails, no one will hear it.

Thanks Fred and everyone. I'll start going through the different possibilities, if I find something exciting I'll let you all know.

Well ... here's the update:
-replaced fuel filter: not starting
-replaced ignition coil: not starting
-replaced fuel pump (and installed access panel): not starting
-checked ground strap on t-stat housing: not starting
-checked distributor: yes it's still there, not free-spinning
-main cable in the back of the engine looks great, no guarantee it's bad but doesn't seem likely.

So .... maybe a TPS (throttle position sensor)?
Maybe a failure of the distributor?

The car is hard to get to with a tow truck, but I'm thinking it may need more help than I can give it.

And second update: checking things over on the engine, looking for vacuum leaks, found a small one on the PCV line. Put a little starter fluid in it to verify spark (again). Car starts, runs, keeps running.

So is that left-over air in the fuel line from the pump and filter ... ????



Any thoughts on this one, just send them along.

The PCV system, not working properly, can cause all kinds of issues. If it continues to run, that may have been your problem.

motor built oil pressure and started,.

I'll get the PCV tube replaced. That's the only verifiable broken thing I can find for now.

Let us know how that works!

Well, I'm not sure how happy the old girl really is but she's still running. Tach is jumping a bit now, thinking I'll put the old coil back in. I was reading old threads and that could be the source. She also hard started this morning but did start. I'm hopeful the pcv line helped the original problem though.

I think I might throw new wires plugs and maybe even a full distributor at it. Last time I did the cap one of the bolts pulled the threads out just a bit. Makes getting it fully tight a bit questionable. Any recommendations on manufacturer?

I also found out that if you don't plug the air temperature sensor in you'll get a CEL. go figure

There are some Chinese distributors on ebay for about $75. It comes with a cap and rotor. They are good mechanically, but the ignition module is questionable. The module should work for a while, but you could put a new Delco, or Delphi unit on it before installing the distributor. Use electrical heat sink paste not dielectric grease when installing it. If you already put a new coil in it, that would be the least likely issue. A cap and rotor is a good starting point. Wires are less likely. It could also have a broken magnet in the distributor. I have seen them cracked, and do not know if it affects the timing or not, but logic would say that it does. A broken magnet could cause a pole at the end of the break, and possibly send a spurious signal to the ignition module. The Chinese ones have a different design for the magnet, so may be less prone to the magnet cracking.

I would replace the distributor, cap and rotor first (since you stripped out the threads). Timing should be set at "0" with the connector separated on the passenger's side valve cover.

Thanks Fred - the coil is an autozone part and seeing as the tach never jumped before I was kind of suspicious of it. You're right about the distributor though, it was fine for a couple of years as it gets 'just tight enough' and with some locktite I was comfortable with it. Now that there are other issues running around though I'll get it gone.

Hey everyone, I 'think' this problem has been chased to ground now. I picked up a new distributor and put a GM ICM in it. I had my usual problem of getting the new distributor seated well (seems like every time I do this, the oil pump tab seems to rotate out of place and the distributor I put back in won't seat in the right rotational location. My method for dealing with this is a long screw driver that turns the pump tab back 40 degrees or so, usually requires many attempts. Tip: put a zip tie around the handle end of the driver so that in case you drop it, the thing won't go all the way through the distributor hole, that would be very bad I think) but finally got it done, tightened down and timed.

She's running great now. I still really like these TBIs.

The long screw driver trick has been around for a long time. I use it too...that or an old distributor shaft.

Glad to hear that it is running again. When you stated that the tach was jumping, I thought about the distributor and ICM. That would be the only thing that would affect the tach, except for a malfunction of the tach itself.

Full disclosure ... I probably got the screwdriver idea from you Fred (maybe the last time I pulled it out and had the oil pump problem?). Thanks, it's saved me twice now.

Here's a picture of the old unit:

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Kind of a dusty, rusty looking mess if nothing else.  Doesn't make me feel bad to have it out of there.

That is one nasty looking distributor, about the worst I have ever seen. Just looking at it would suggest that it was your problem. The rust on that one is really fluffy.

Did you try to remove the connector from the ICM? They are usually so brittle that the shatter when you try to remove them.

The last time I installed a distributor cap, I rotated the distributor so the back screw was accessible, then reset the timing. It actually took less time and aggravation than fighting with the screw in the back.

I didn't try the connector, just threw the whole thing away and started working on the new one. Great idea on how to get the cap on more easily, I'll file that one away with the screwdriver technique.