95 LT1 383 stroker running rough

**edlin1127** · 01-05-2012, 07:11 PM

i have a 95 Z28 with a 383 stroker built by Callaway Motors. The engine started running very rough like we had bad gas. After draining the tank and running cleaners thru it, it isn't much better. We found the #8 cylinder is dread. We pulled the valve covers and the valve train is good and functioning. The spark is good at the unit but we haven't checked it at the plug yet. We will check the injector to make sure it will function properly.
Has anyone else experienced or heard of this problem or have any other ideas to share?? Thanks

**93TransAm** · 01-20-2012, 09:40 AM

Spark plug 8 probably is loose. My buddy had his wires and plugs changed at a shop that half-assed it and didn't tighten the rear plug because they were worried they would break the dipstick. Which they did anyway and still didn't fix the plug after replacing the dipstick. Stand on a block, turn your wrist sideways, and place the spark plug socket on first then the wrench. I prefer to have the vehicle jackedup in the front so I can go top to bottom to figureout which position is feeling easier for me. Just take your time, don't get pissedoff at the car and think about the best way for you. Something much easier said than done lol if it isn't loose check back and we'll throw more ideas at you. good luck

**edlin1127** · 02-22-2012, 06:39 PM

Well... checked the plugs and wires on all 8 cylinders. All were good but #8 cylinder acted dead. Checked the valve springs and they aren't broken. A friend has a bore scope and is going to look inside. Last resort is to pull the head. Any other ideas???

**cpop98ws6** · 02-22-2012, 06:47 PM

Compression test?

**5.0THIS** · 02-22-2012, 08:15 PM

Get a cheap infrared laser pyrometer, run the engine, and check the exhaust header about an inch out from each exhaust port. If you have a dead hole you're going to see a significant difference in temperature at that cylinder.

**edlin1127** · 03-17-2012, 04:40 AM

here is an update if anyone can help. #8 cylinder is dead. Car runs on 7. Plugs and wires are all good. Valves and springs are good and functioning. Scoped the bore and no signs of problems. Switched the injectors around still #8 not responding. Haven't done a compression test because the headers are in the way.
Does anyone have any other suggestions. If not, next steps will be remove header, compression test and pull the head (if test doesnt tell us anything else).

DOES ANYONE HAVE ANY OTHER IDEAS???????? WE ARE RUNNINBG OUT OF IDEAS AND OPTIONS. Thanks to all for your suggestions.

**thearborbarber** · 03-17-2012, 08:57 AM

Do you have a noid light to see if #8 injector is getting the command to fire?

Have you or do you have a scanner to see real time data as the engine runs? If so what information are you getting? Mainly want to know codes, fuel trims, maf and o2 sensor reading. You could have a sensor error that is causing the whole bank to be in error buts its slight enough to show up on cylinder 8 since its the further back.

**5.0THIS** · 03-17-2012, 07:05 PM

This car needs to be scanned with a GM tech2 scanner or something similar. I agree with the above that the injector may not be firing at this point.

**edlin1127** · 07-21-2012, 08:42 AM

Well guys.... we have found the culpret... now we need to fix it. it appears the Opti-spark is not properly triggering the injectors. The engine was built by Callaway. The injectors were not properly triggered and we in the on position all the time. That's what caused the rough running. We replaced just the module and it improved slightly but not completely. We will be replacing the W/P at the same time as the Opti-spark so this doesn't happen again. If this is the final I will reup the post.