what am i doing wrong?

[CapriceLT1]

It had a stock LT1 module in it (with the code still there) So I put an LT4 module in. I have new sensors and the connectors that run from the KS to the PCM (port 22 blue i think if i remember right off hand) are new as is the wires so that i can rule out any burnt or corroded wires and i have fresh one running to the blue wire (prong) on the PCM where the original wire was, i connected the new ones there. After all that it seemed better but as you can tell i am not where it should be. But iv been driving it like this since January, is it really bad for me to drive it? I know its certainly not good but HOW bad is really the question i guess

[EagleMark]

Well pig rich and no closed loop while knock is pulling up to 15 degrees timing? Mine pulls 1 degree at 5100 RPM inbetween shifts...

Check the oil and smell it! If it smells like gas then your washing out the oil in cylinders...

It's running bad, your MPG must be horrible...

[CapriceLT1]

Well pig rich and no closed loop while knock is pulling up to 15 degrees timing? Mine pulls 1 degree at 5100 RPM inbetween shifts...

Check the oil and smell it! If it smells like gas then your washing out the oil in cylinders...

It's running bad, your MPG must be horrible...

Last summer 17mpg, with this code 43 im getting 10 mpg on average. so yea. I work at Napa and im getting a new pcm because i had my friend at the shop go through it all to make sure i didn't do anything wrong and everything was right and he said hes worked on an LT1 with the same problem and the one wire/connector (something) inside the PCM was burned out. So for 80$ i have a new PCM flashed and ready to go on Tuesday. and there is no gas in oil. After I put the new one in everything should be back to normal (fingers crossed) and I will let you guys know whats going on. My current pcm has a crazy amount of salt rust build up, that's what i get for living in NY lol. You guys are awesome on here, you actually respond to my posts and i really appreciate it!!


But the cats overheating? Can you explain that one?

[EagleMark]

But the cats overheating? Can you explain that one?

It is in Cat Conv overtemp mode which would make it run rich to cool off cat! That is a issue that needs to be addressed and with codes set that has to be addressed first. Then a data log to see when Cat Conv overheat temp mode comes on and why?

[CapriceLT1]

why the new PCM? Because i have new sensors, connectors and wiring to bypass the wiring harness and the only thing left would be the PCM. I have continuity and the correct amount of power so there is nothing left. Its 80$ for a reman'd updated flashed PCM for me so i figured why not since i talked to a few shop buddies and they said the same thing and they have seen it happen. LT1's are mechanically strong but in WNY area the weather and rust destroy all the electrical stuff lol

[EagleMark]

I've seen weird issues with ECM/PCM as well that do not show up on any test, rare but does happen. Are you saying your shop buddies know this Cat Canv Overtemp is a known PCM issue or just the general PCM weird issue? I like to know, known issues! This is one I have not had to deal with. Normally if a cat is in or near overtemp it is cooled down by richening mixture and happens quite fast and goes off...

[CapriceLT1]

I was talking about the Code 43 being related to the PCM since that is what i rewired and re did everything. I didnt ask anything about the cats though. Tomorrow i get the new PCM and that should clear up code 43 and maybe cat temps (fingers crossed!!!!!!!!!)

[CapriceLT1]

New PCM. Runs better i think but code is still there after re-setting comp multiple times. Only thing I can think of is battery grounds. What do you guys think? And i know we went from "how to use tuner pro" to "whats wrong with my car" so if you want me to post in another section just let me know

[CapriceLT1]

Just to keep everyone in the loop. I am putting grounding straps and cables all over my vehicle as i think thats part of my problem and I also defected the knock sensors i got from work and got new ones so hopefully the code 43 will go away and i can start tuning. But i cant start until the codes are gone?? And EM! the BLM WOT throttle blocker ( i think thats what its called) what does that do to performance/fuel mileage etc??

[EagleMark]

Grounds can always be considered especially in the salt winter states.

Well you've done the LT4 knock module conversion with knock sensors, PCM is now ruled out.. just opened up a PCM I have here on the bench and there's 8 pins, pretty robust and visable in PCM, not visable at all in knock module unless you pull module out of white plastic holder, so I'd have to pull it apart and see that no pins are bent etc... in that! Do you still have the old LT1 knock module to pop in and see if code 43 goes away? If pins are fine could we be dealing with a failed LT4 knock module?

Did the Cat Conv Over temp go away with PCM change? Curious if the 2 are related?

Have you checked over at ImpalaSS forum to see if anything needs to be changed in bin with the LT4 knock conversion? I've never done this...

[CapriceLT1]

Sorry for getting back so late. I dont think anything needs to get changed in the bin file but will double check. With new PCM I still have CATs overheating. Everything else seems to be normal. I actually did a log after the new PCM. I am going to re-check the wiring and add another ground or two. My battery cable giong to the starter was totally corraded as was the studs on the starter so they broke off when i went to add the ground. I think my battery is going bad, and I am going to defect the knock sensors i have and i have a warranty on the battery so that should hopefully get done tonight and I will let you guys know what I am dealing with.


No tuning whatsoever with the code on? I'd like to add the BLM WOT blocker since it might help with gas mileage right? Thats what it does?

[EagleMark]

The WOT BLM Locker locks BLM and INT readings to 128 at WOT so PE fuel is actually adding to AFR. It is for power, not MPG.

There's no temp sender to say cats are overheating, it's a calculation from the way PCM is running, so it must be lean. Have you checked fuel pressure? Post a log.

[CapriceLT1]

Heres for your lt4 knock mod question


http://www.impalassforum.com/vBulletin/showthread.php?t=273248


will post log asap

[CapriceLT1]

Alright....My 9C1's transmission is going, it needs paint and the knock sensors all tested ok along with the connections. Theres electrical issues and it runs like crap. New trans is worth more than the car so Im taking the motor out since thats still good, keeping the harness and new comp and parting everything else though. I just bought an S-10 stepside 3 door(4.3L W/TOW package) and thats really what i need. needs an o2 sensor then, I can finally tune a vehicle! I am going to miss my 9C1 though, but there are somethings you just have to let go... :(


I will deffinatley be asking for help on the "sten". Hopefully better tune for mileage and slight power. not much power but ya know, a lil gitty up

[EagleMark]

I've been threatening to put my LT1 and trans into an S10, or a G body... hope to see your project build!