98 Lude I/H/E, stage 2 cams, P28/Hondata S200, dyno tuned. My car randomly misses and sometimes dies, only with the P28. With my stock P5M ECU it runs crappy but never dies. Have swapped/ replaced another P28, main relay, ignition switch, cap, rotor, plug wires, fuel system fine, electrical grounds, etc. The car will start back up sometimes right away or after a couple of minutes. I have researched this problem extensively and now suspect the dizzy or ICM. Now for the question... Is it possible the more aggressive timing in the P28 is pushing the dizzy/ICM into intermittent failure? No CELs in either ECU yet to diagnose this. I have been struggling with this for a few months. Any thoughts or insight would be much appreciated.

 

what kind of distibutor are you using?

 

Original stock OEM TD77U

 

so you have your ckp ont he cranka nd you are using obd2 dizzy correct? everythign is swapped to obd1 and you are usign p28?

 

Only thing OBD1 is P28. Prelude CKP is on crank, CYP in dizzy for OBD2. This same setup worked perfectly for four years. Started having probs after last dyno tune when we increased timing. First Hondata tune was street tune. Then put it on the dyno to fine tune for power and check A/F.

 

well i say do compression test, as from the sounds of it when you tuned it alst time you may have made contact with the valves.

do comrpession test and come back.

 

We adjusted ignition timing not cam timing. I have seen posts on this forum and others with the same random dying issues that were fixed replacing an intermittently faulty dizzy or ignition control module. Car does not exhibit problem with stock OBD2 ECU, only the P28 with more advanced ignition timing. I am wondering if the P28 puts more stress on the ICM, causing it to be intermittent. Thanks for your help.

 

^ oh my bad , i thought you meant cam timing.

 

my ICM was overheating on my internal coil dizzy causing the same problem. it usually took about 15 min to an hour to start up again once it cooled down. you get no spark when it dies?

 

It is so random I have never had diagnostics when it happens. It will run great for 2weeks, then stumble and die, summer to winter, usually after I think I have it nailed. Drove for 3hours down the Interstate, 15mins later died, fine for two weeks. If I didn't love my Lude soooooooooooo much, OVER THE CLIFF!! Some say wiring prob, intermittent WHAT? My insanity. Thanks for listening.

 

^ yep, I know what you mean. I got stranded at the side of the highway when it happened to me. waited around for an hour trying a bunch of stuff until a cop told me I had to get the car out of there. finally broke down, pulled the bumper off, and got it towed back home and it started right up after it came off the truck. didn't do any troubleshooting, but took a chance and bought a used dizzy and it's worked fine since. drove it 4 hours from iowa to chicago multiple times.

intermittent problems suck.