I can't find anything conclusive with a search.

I'm working with an 88 5.0, tbi.

Basically, this is what has happened, the car is running great. I turn it off, get some groceries, get ready to leave and it doesn't start. The starter turns the motor over. I check the fuses. They're good. I call a friend. We check for fuel and spark in the parking lot. He's doing the checking, I'm turning the engine over. There is no spark. The lighting is dim and he's not sure he sees fuel but he's fairly certain he saw no fuel. So we switch places. He turns the key and it starts and runs great. I drive it home.
Today, I drive it to work. It runs great. No signs of any problems. After work I go to the gas station to fill up. When I'm done filling up, it doesn't start. So we check it again. No spark. No fuel. Fuses good.
I replaced the throttle body base gasket a couple weeks ago. I visually inspected it and double checked the wire connectors and fuel fittings and found nothing out of the ordinary. I've done nothing else to it.

My Haynes manual appears to be useless for this problem. How do I go about diagnosing this? We think it has something to do with the ignition. But, like I say, my Haynes manual is useless and doesn't offer much in the way of trouble shooting. It doesn't even have a wire diagram for a tbi equipped car.

 

i've seen a distributor pick-up coil or module cause that if there is no spark and no fuel.

 

I second that

 

So how do I go about trouble shooting the module and pick up coil? I want to avoid throwing parts at it if at all possible.

 

About the only way to do that is to test it hot, which isn't easy. The coil can be checked for resistance when this happens.

It isn't unusual for either the module or coil going bad and taking the other one out, though.

 

I'm up for a challenge. So how do I do it?

 

if you remove the cap and rotor and the pickup coil is rusty that's likely your problem. its easier to just replace the whole distributor.

 

Agreed. Those TBI distributors are pretty bad about that. Get nasty over time.

 

I appreciate the advice on where to look and what may be the problem but I don't want to resort to swapping parts. They aren't particularly cheap and I don't want to spend the money on something and have it not be the problem. So please, let's focus on diagnosing the problem to start.
Is there a procedure to diagnose this? If so, what is it and how do I accomplish it?

 

ok. i've been a professional mechanic for 15 years. the problem you are having, us mechanics call an intermittent problem, meaning it only occurs sometimes. all you can do with an intermittent problem is repair the possibilities. if the distributor is rusty thats likely 90% of your problem. i would start there. look for one at a salvage yard, if it isn't rusty and ohms good i would try it.

 

It's not intermittent. It plain won't start. So I can diagnose it. What do I do to make sure it ohms good?

I my not have been so clear. The second time it wouldn't start, it seems to have been for good.

 

the way you explained the problem, it ran good, you got groceries, then it wouldn't start. your friend came over you both looked at it then it started without repairing anything. you drove it to the gas station, then after getting fuel it wouldn't start. that is called intermittent. are you saying it was intermittent at first now it doesn't start at all? my distributor ohmed at 800ohms. does your pickup coil appear rusty?

 

Yes.

I haven't had time to check anything since I got the car home. It was towed.
Which terminals do I use to measure the resistance?

 

Is the tbi distributor the same as a tpi distributor? I can use the tpi wiring diagram to figure out how it works if it is.

 

no. is the pickup coil rusty? unplug the p-u coil from the module and ohm the coil.

 

I haven't looked at anything or tried anything since getting the car home. The Haynes does show how to check the coil and we tried to check that before towing. My multimeter leads don't seem to fit into the coil far enough to get a reading. My plan is to go to the junk yard and cut off some connectors so I can check the coil.
Can I do a similar check with the module and pickup coil?

 

here is what you will do to check if the distributor is bad. with the distributor in place and all the spark plugs wires connected in their corresponding order unplug the number 1 sparkplug wire get a ling screw driver place the end inside the cable touching the connection were the sparkplug sits have some one sitted on the driver sit to crank the engine """""CAREFULLY"""" without you touching the metal on the screw driver (it will shock you) have your buddy turn the key and at the same time arc the screwdriver with any metal part in the car.(i usually arc it to the alternator since its closer to my 1 cylinder) if it produces a spark then youll know that ur distributor is working fine

 

Just wanted to add that if you do perform a visual inspection of the parts, this is how to tell a good pick up coil apart from a bad one:

Not saying it's hard to tell, but it might be worth checking out. Cause when they go, like mine did, you will get ignition problems, like I did.

 

I have already checked for spark. There is none.

I plan to do a visual inspection. When I do, if I find anything looking like that in the picture, you bet I'll replace it without bothering to check it.

 

Random no spark/no start condition.................2x ignition module.
Common GM issue.

 

I'm betting its that. That randomly happened to me one time when i was at my girlfriends. Her dad said its either fuel or fire and there was fuel so he pulled the cap off and said here replace this pickup module and it cranked right up again..

Fuel or Fire.. thats always stuck with me

 

Apparently it is still intermittent. I went out to look at it this morning. Before I do anything, I see if it will start and of course it does. So my theory is that it has to do with heat soak - the temperature rise under the hood after turning the car off. To test it, I drive to my friends house, shut it off, start it, shut it off, start it - works like normal. Wait 20 minutes and it doesn't start. I checked my grounds. I checked the coil as outlined in Haynes and it is good. Haynes does have a check for the pickup. It checked good. I found out that Advance Auto can check modules so I pulled the module and had them check it. It checks good.
So with that, I put it all back together and it started right up. I drove it home. When I got home something great happened, it died while running and doesn't start. The timing was perfect. It died as I was pulling into the driveway. So I'll see if it'll start in a few hours. If it doesn't then I'll see in the morning. Hopefully it will be for good this time.

 

I once had a loose ground for my fuel pump wire and it would randomly turn on and off. I believe the ground for the pump is to the left of the battery, check that first

 

If a bad fuel pump connection can simultaneously cause a no spark issue, I will take a look at it. Can the fuel pump circuit cause that?
The car did start this morning.

 

I have the same problem with a 89 305 TBI. The TBI is shooting gas. I changed the fuel pump and fuel filter. I can hear the fuel pump prime. When I start the car it starts, run for about 2 second very roughly and then shuts off.

I pulled the number 1 plug wire and plugged a spare spark plug into it. I am getting spark.

I took the distrubutor cap off and it is rusty. Is it possible that I am getting some spark but the distributor is not working properly?

If I need to replace the module and pickup coil I would prefer to do that as I am skittish about taking the distrubutor out. I like Charley am stumped.

 

Taking the cap off the distributor is easy, your not actually pulling the whole distributor out. Theres 4 ends that hold the cap onto the distributor. You will use a philips screwdriver to push down onto the bolt and turn it away from the distributor. Do that to all four bolts and you will see how it holds it in place. You will also notice the four spots on the distributor that have a notch in them that tells you where there supposed to go back to. Then the pickup module is just bolted on and make sure your weights and springs aren't too rusty.

 

My problem seems to be solved. I made a couple attempts to diagnose it since I figured out what to do to get it to happen. I couldn't find anything wrong with anything I was able to test. If my theory of it being heat related is correct, by the time I got the module out and to the parts store for testing, it was cool and their test cannot duplicate the actual running conditions. In testing things, the connector for the pickup coil just fell apart the first time I tried to remove it. The thermal compound that should be under the module seemed to have long since disappeared. Those two parts alone were very nearly the price of a reman distributor. So I got the distributor and have not had the problem again. My suspicion is that it was, as other had mentioned, the module.
After thinking about it some more, simply using the old module with new thermal paste may have been a satisfactory fix.

By the way, my distributor cap is held on with 2 screws. Is it not the same with an '89?

 

Not sure but i have an HEI distributor

 

Hey guys. I seemed to have a similar problem yesterday. My '83 has a carbed 305 and I'm wondering if your thoughts are the same for the module. It ran great on highway driving for an hour and a half then died pulling out of a drive through. Was hard to start. After cooling off (15-20 minutes) started but would bog hard at WOT or even less. After running 20 minutes or so it would want to die and then I'd wait to re-start. This happened about 4 times. Finally as the temps dropped at the end of the day I was able to drive at low RPM highway driving which seemed to keep the temp of the engine down (I had the heater on as well to help) Changed the fuel filter recently and changed it again (happened to pass a Napa on the adventure home). That didn't seem to help at all so I don't think it's fuel (bad gas was one of my first thoughts but the low engine temp helping wouldn't apply, right?)

So is the same module a possiblity? What do you think? Oh, and BTW, last fall I changed to an MDS distributor cap and rotor with an Accel HEI super coil. I don't recall changing the module though. Would it have been a part of the swap and I don't remember or is it a totally separate piece inside that I may have left alone?