I read your earlier suggestions sorry I did not reply. After engine cut off I cranked no signal RPM gauge.

 

You'll need to crank it for several seconds (~ 8) if still no RPM indications show up on the gauge during the cranking cycle then the problem is most likely the distributor (ICM, pickup coil, weak reluctor magnatism, connectors, &/or wires to/from the dizzy (distributor). The pickup coil is a bit of a pain to test or swap out. sNAPA sells an entirely "rebuilt" drop in replacement distributor for ~ $150 may be an "easy" option to consider.

 

What cutter said would be my quess after all you replaced. You said for sure that you know you do not have fire. only a couple of things can cause that. lost 12 volt feed to dist. something shorting the tach wire to ground. ing module, coil, or pickup coil. on 88 you should be able to disconnect the ecm and still have fire so you can more or less rule that out also. My opinion is you are jumping around to much. If you have no fire stick only to the things that can casue this. stay to where you know the problem is in this case you should not be looking at maf, injectors, or anything that has to do with fuel or air. The hei system is very simple and not to many peices to the puzzle.

 

Thank you for your reply and help, I will do more tests I will replace distributor pick up coil.

 

Thank you for your reply and help, I will do more tests I will replace distributor pick up coil.

 

Thank you for your suggestions, I will do more tests as you suggested.

 

Agree with Black89Z51. The injectors on 88-89 are the source of many problems. Ohm the injectors

 

I had this problem and spent months chasing it down. The final tests were simple.

When the engine won't start, (1) unplug the connector that you unplug to set base timing. If you can start the car then, it indicates a bad pickup coil. (2) unplug the MAF, if you can start the car then, it's a bad MAF.

In my case it took two tries when the MAF was unplugged to start the car, but it would start on the second try each time the problem occurred, so I replaced it and the problem vanished.

If not that, from what I've read in this thread, you may have a bad coil. Good Luck.

 

Pickup easy to replace. Pull cap,mark where rotor is pointing on dist. so you can put in in at same location.Remove roll pin on gear and pull off.
Watch how the pieces come off should be a shim and a washer .Replace pickup clean and lube as needed.

 

I just replaced pick up coil, started up running, again cut off at temperature 168 I tried to restart cranked it I smell gas wont start, I hooked up my timing light there is no spark.
Found no diagnostic trouble codes. Any suggestions?


Work completed:
Cleaned throttle body, replaced MAF, power and burn off relays, new ignition capacitor, pick up coil, ignition module, rotor, distributor cap and spark plug wires, also coolant temperature sender and oxygen sensor, adjusted TPS .54 fuel PSI 38 it is normal. Fuel injectors:
Cold 16.4~16.3~16.3~16.4~16.4~16.4~16.4~16.3.
HOT 17.2~17.0~17.2~17.3~17.2~17.2~17.3~17.3.

 

No spark at operating engine temp is a common problem with older HEI modules inside the distributor and they aren't expensive. You said you replaced the ignition module, do you mean the HEI module inside the distributor? The spark coil is also suspect, but rare for it to fail hot and recover when cooled down. Spark coils aren't expensive either. I would replace both, a worthwhile experiment.
When hot and it won't start, I recommend checking for pulses at the ppl/wh wire out of the distributor during cranking. This wire has reference pulses out of the distributor to the ECM and pulses prove that the pickup coil and the HEI module are working properly. An oscilloscope is best to view pulses, but your a.c. voltmeter may indicate output volts on this wire. Try your a.c. voltmeter on this wire when the engine runs to determine if it can measure the pulses. You can also see if there are pulses on the white wire out of the distributor which goes to the tachometer and this wire is connected to the primary of the spark coil, so no pulses means no spark. The spark coil primary gets 12v pulses from the HEI module inside the distributor. If you get no reading on your a.c. voltmeter, first try reversing your voltmeter probes when the engine is running (known pulses) and if your voltmeter doesn't respond, you will need to gain access to an oscilloscope.

 

 

Thank you for reply and advice, I will make tests as you suggested, this is the first time ran into this issue, I have maintained my ride ever since vagranty expired. Thank you and all the members for their support.


Following tests made:
When engine is hot and cuts off, found no diagnostic trouble codes while cranking fuel PSI is OK, but there is no spark tested all fuel injectors:
Cold 16.4~16.3~16.3~16.4~16.4~16.4~16.4~16.3.
HOT 17.2~17.0~17.2~17.3~17.2~17.2~17.3~17.3.

Work completed:
Cleaned throttle body, replaced MAF, power and burn off relays, new ignition capacitor, ignition module (HEI module), pick up coil, rotor, distributor cap and spark plug wires, also coolant temperature sender and oxygen sensor, fuel filter, adjusted TPS .54 Started up runs great, again engine cut off at normal temp, there is no spark while cranking smell fuel.

 

Have same problem, did you ever find a solution?

 

My 88 did the same thing...Replaced the injectors and ECM...problem gone !!!!!

 

I have same problem,94 c4 ive done everything except replace the ecm .i think thats my only option left,i think it dont show codes cause the brain itself wont tell on itself if that makes sense. ecm wont detect an internal failure .i'm really tired of this engine/ignition setup wanna put a 383 crate engine in it with old school dist on it .ide rather deal with a carb than being stranded on the freeway over and over again.

 

Since the original poster never told us what solved his problem on this OLD thread, we'll never know. Maybe he sold the car...

The symptoms (no spark when hot) are what happens when you either don't use any grease under the ignition module or put the wrong grease there. It should be THERMAL grease, NOT dielectric grease.

The ignition module gets REALLY hot and will shut down if it overheats.

 

just had mine fixed what happened was the water pump was gradually leaking and believe it or not it is right over the distributor so guess what it leaked into the distributor and wala car needed repair would start when cold but not when warm would not even stay running when warmed up. so had to replace water pump and distributor to the nice ring of 1600.00 but you know the old saying you wanna play your gonna pay.

 

97 degree temp on a slow highway going around 25mph, 4 miles out and the car drops to nothing. Wait for around 10 minutes and it starts up again. I'm guessing that Cliff is correct, it would be easy for a mechanic (we just replaced that module) to use the wrong grease. Will try to post the results to this.

 

Better off starting your own thread this one has been kicked up enough