I've been trying to take care of this problem for probably a year and a half now its gotten to the point where its unsafe to drive.

Basically whats happening is a bog/skipping under load usually between 1k-2.5k rpm. Sometimes the car will completely shut down and usually starts back up and runs fine for 10-15 minutes before bogging or shutting down again.

The problem seems to occur more when the weather is warm.

I pulled codes a while back and originally thought it was my opti but it wasn't the problem.

So far, I have replaced the following:
optispark
coil
icm
plugs + wires

At this point, Im thinking about replacing the opti wiring harness but I'm not sure about it since the problem is so intermittent.

Another thing I noticed that occurs rarely is when I start the car up after its been sitting, my temperature gauge tops out, the check guages light turns on and within two minutes it goes back down to the true temperature and the light goes away.

With all of this going on, im slightly overwhelmed and I don't want to chance driving simply because I don't want to get stuck in an intersection or a dangerous situation.

I will post up the codes I pulled when I get to my home computer.

 

The gauge is driven off the coolant temp sensor in the dirvers side head, and has nothing to do with the PCM or the way the car runs. Sounds like an intermittent wiring problem. You may have a bad ground.

Scan it again for codes. What codes did you get last time, that led you to replace all those parts?

 

16 lo-res fail
36 hi-res fail
41 est open
48 MAF system fail
51 EPROM/Flash Checksum Fail

I'm going to scan it again later this week, but my data cable is at my townhouse at my college.

 

How did you address the MAF code?

 

Other than the gauges freaking out, I have been having the exact same problem with my car. It bogs like crazy, shakes badly, misfires, starts popping if I get on the gas too much, basically everything you explained, and it seems to get worse during the day when its hot out. It has been very frustrating, and cant seem to figure out exactly what the heck is happening. If anyone has any ideas it would be very much appreciated, also, here are my codes just for the heck of it..
P0300
P0400
P0420
P1441

And yes, I have done searches, but no one seems to have a answer that has helped yet.

 

I believe that maf code was an older code from when I did the opti and forgot to plug it back in before trying to start up the car. I am going to clear the codes out tomorrow and see if could be a potential issue or not.

 

I've heard some members did a fuel pressure test,and that was the problem.Fuel pump.Seems to go south when you run out of gas.My02.Hope this helps.

 

x2,this deff. sounds like a fuel starvation problem.

 

I read the codes on the car again today. That maf code was an older code caused by it being unplugged. At the moment I have the following codes...
41
42
46
51

any ideas?

 

This sounds like an air fuel mix problem. LT1's there have two engine temp sensors: one goesto the dash guage and the other to the ECM. if the sensor is bad to the ECM as the engine heats up the engine runs more erraticly. If the sensor that goes form the oil resevoir to the dash guage is bad you will get erratic reading guages. The two are cheap to fix.

 

well yesterday, I hooked up my laptop and cruised around monitoring the system and codes and the motor never left closed loop and I couldn't get it to act up. I'm not sure if those codes are current or not. What is the easiest way to clear to codes in order to test again when the weather is hot enough to cause it to act up? I figured just disconnecting the battery for a few minutes.

 

There is no engine temp sensor in the "oil reservoir". The dash coolant temp gauge is driven off the 1-wire coolant temp sensor in the driver's side head, between #1 and #2 plugs. The Corvette LT1 has an oil temp sensor, but not the F-Body LT1. But even the Corvette oil temp sensor does not drive the dash coolant temp gauge.

 

Oil level sensor maybe? but I didn't think that would cause misfires or poor running (until it ran out of oil )

 

Hey I am also having the erratic bogging and misfiring when it heats up. Just like everyone else's condition, its only been happening this summer when it gets really hot. First I suspected my spark plug wires, but after replacing them today with going over the valve covers, I'm still having bogging and no HP. Plus if I cruise at like 60-65 it will hesitate and misfire more noticeably. I looked at it from behind while it was idling and noticed I'm getting some seriously nasty black watery liquid out the tailpipes that is spraying out all over my driveway. I know this isnt normal h2o burn off and carbon, i was thinking the misfiring was leading to gas being burnt off or steamed in the headers and collecting soot and liquefying. If anyone else is having nasty black spatter out the exhaust let me know because it only started when my misfiring and hesitating started up. And Im positive because all that black spray on the driveway is recent

Edit: to d2stephen: It shouldn't be gasket related, because it acts up only when it warms up, and no sooty crap when its cold, so I know its very close to RKPsk8er's car

 

That sentence does not make sense cause the engine starts in open loop and then switches to closed loop. Did you mean to say it never left open loop?



You need to monitor this post only but start your own if you need help.