Tired of slinging parts at my car, need some serious help.. Recently I rebuilt my upper end.. found that the knock sensor wire had been burned through.. sodered a new wire in place, heat shrinked it, and wrapped it all back up with that heat resistant tape. Took the EGR out put block off plates on. replaced the coil, ICM, plugs, reprogrammed the PCM and put an LT4KM in. The car runs great when it's cold, but when it heats up, it starts running like crap, like it's missing, not enough vacuum something, I can't quite put my finger on it, but since it hauls *** when I floor it, I'm betting on vacuum or fuel supply. Any ideas or a direction to look are greatly appretiated. Thanks in advance

 

have you thrown it under a scanner? PS I have a AKM cable and datamaster for a 95. I am in Austin and will probably be in houston later in the week.

It might be something as simple as a temp sensor... who knows. Look at the sensors and see what they are seeing. If everything is kosher... then you start down the logic tree.

 

I would start by scanning it also. The LT4 KM mod did a fantastic job of adding massive amounts of false knock to my setup. This of course contributed to a lot less ignition timing than it should've gotten, surging, bad fuel economy, stinky idle, it would "lay down" under throttle, etc., etc.

I've been preaching this for far too long. Don't put an LT4 KM in a car unless you have false knock and always check to see if the situation improved or worsened after the "mod".

 

I have been saying that about the LT4KM on this board for a long time. It has never fixed a thing.
Put it on a switch with the resistor on one side and the factory set up on the other,best of both worlds if ya got false knock. Run the factory stuff on hot days and the resistor on race night.

 

It was doing it prior to the LT4KM, I just wanted to see if it would fix it. Was slingin parts No I haven't hooked a scanner up to it. and no I haven't thrown any codes, but my next step was to get a cable and do so. btw, I'm in Rowlett which is about 10 mins from Richardson and 15 from Dallas, Auston/Houston is a little bit of a drive for me. Thanks for the offer though is it possible since I repaired the wire to the knock sensor, the wire I used was much larger than the stock.. would that make a difference? And could I just be getting a lot of false knock?

 

It sounds like your O2 sensors. The car runs great when it's cold because the PCM ignores input from the O2's (open loop) until the AIR pump has enough time to heat them up to engine operating temp. If you have a bad O2 sensor, it will send faulty data to the PCM reporting a lean condition which the computer compensates for by adding more fuel and making your engine run pig rich. The reason it hauls *** when you floor it is because when your TPS reports a WOT condition, the PCM goes back into open loop and once again ignores input from the O2's, so for that brief moment it runs as it should until the RPM's drop back down enough for the system to go back into closed loop. Do this test: try unplugging your O2's, let your car run for a solid 10-15 minutes until it's fully warmed up, and then plug them back in successively until the last one you plug in causes the engine to start running like crap again. That will pinpoint your bad O2.

 

False knock is very likely. There is a bunch of info on this from past posts. Do a search for LT4 KM/False Knock/Resistor for false knock/timing retard/ect,it should keep ya reading for a while.

 

O2's are brand new I hope it wouldn't be those

 

If the O2's were bad or going bad and cause the car to run like crap, wouldn't it throw a code? Also, I removed the EGR but I don't believe it was tuned out, could that cause a problem when it heats up?