Another '93 suddenly stops running, no code
Thread Starter
Army Hoist Operator
Joined: Feb 2009
Posts: 836
Likes: 17
From: OK
Another '93 suddenly stops running, no code
No mods, replaced coil about 6 months ago because engine missed and then died. Now the engine will run for 35 minutes, then I turn it off while at work or at church for a couple of hours, it will start and run normally and then quit suddenly after 10 minutes or so or even longer. No misfire, no hesitation, just quit. After it sits for a few hours, it will start again. 3 trips on a rollback this weekend. I got one flicker of a SES light once but still no codes. Well, an H72 and H74 but those have been there intermittently and are probably because of the haphard previous onwer installed stereo.
It sounded like a typical ICU failure so I replaced it. Died again today. I haven't started formal FSM troubleshooting yet. The lack of DTC is puzzling. Hopefully I can get it sorted tomorrow. Suggestions are welcome.
On the way home this afternoon, we saw a black C4 with a red racing number on a trailer pulling off I35 at Covell in Edmond, OK. I'd like to meet the owner/driver.
It sounded like a typical ICU failure so I replaced it. Died again today. I haven't started formal FSM troubleshooting yet. The lack of DTC is puzzling. Hopefully I can get it sorted tomorrow. Suggestions are welcome.
On the way home this afternoon, we saw a black C4 with a red racing number on a trailer pulling off I35 at Covell in Edmond, OK. I'd like to meet the owner/driver.
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
When it dies and won't restart, what is it missing? Spark, air, fuel, rotation or compression.
Ok prolly rule out compression and rotation given this scenario.
So get a cheap spark test tool, a fuel pressure gauge, and a multimeter.
Some things to try...
When it won't start, unplug the odd injectors...no change? plug them back in and unplug the even ones. If it starts on 1/2 the injectors plug the remaining ones in one at a time until it won't start.
Backprobe the TPS and manually open the throttle watch the needle on the volt meter swing from nearly zero to nearly five volts.
Forum search on how to clean and R&R the idle air controller.
Try starting the car with no throttle, 1/4 throttle, and WOT any difference?
Read the resistance of each injector. There are posts on what you should see and how to check them. But essentially if you find one or two that are very different from the others post the numbers here.
Disco the vacuum line to the FPR and check it for wet gas.
Read the fuel pressure before start, while running, after shut down, and 30 mins after shutdown.
When the key is inserted and turned to run (not start) do you hear the fuel pump run then shut off?
Ok prolly rule out compression and rotation given this scenario.
So get a cheap spark test tool, a fuel pressure gauge, and a multimeter.
Some things to try...
When it won't start, unplug the odd injectors...no change? plug them back in and unplug the even ones. If it starts on 1/2 the injectors plug the remaining ones in one at a time until it won't start.
Backprobe the TPS and manually open the throttle watch the needle on the volt meter swing from nearly zero to nearly five volts.
Forum search on how to clean and R&R the idle air controller.
Try starting the car with no throttle, 1/4 throttle, and WOT any difference?
Read the resistance of each injector. There are posts on what you should see and how to check them. But essentially if you find one or two that are very different from the others post the numbers here.
Disco the vacuum line to the FPR and check it for wet gas.
Read the fuel pressure before start, while running, after shut down, and 30 mins after shutdown.
When the key is inserted and turned to run (not start) do you hear the fuel pump run then shut off?
