Hoser66

First i need to say i am totaly new to the LS1. Give me an old style motor and i can tune the dog out of it, but im lost when it comes to the new style with all the electronics. So any help would be great!!!! I guess i need to start from the top, I bought a 1998 Chevy 1/2 ton that the owner had an engine swap done from the v6 that was in it to the 2004 LS1. There has been a lot of after market parts installed also. "FAST" throttle body and intake. "FAST" fuel rails. MSR coil packs and so on. Trying to keep this short as possible here is the issues i have right now. At startup the engine idle is fine, touch the throttle and it jumps to 2000rpm and hold there for about 10 sec before returning to around 1000rpm. Tried cleaning the IAC valve and fixed it for a day or so and right back it came. Also, the engine temp showed to be running hot(Around 240 on the guage in the dash). Checked all areas on the block and heads with temp gun and showed around 190 to 200. No boilover of any kind. I changed thermostat and temp senser, still showing around 240 on guage. ????? These are the main 2 prob i am haveing right now!!! Have know idea how to start on fixing them at this point. Engine is supposed to be controled by a stock 2004 corvette ECU. Thanks for any help with this!!!!!

murphinator

iTrader: (2)

sounds like it needs a tune , asking a stock ecu to control it with "a lot" of aftermarket parts is asking too much of it , lurk around your local section of the forum and find out who the good tuners are in your area and you should be a lot happier.


The temp issue seems like its faulty guage or sender which you allready swapped , bad guage ? or an issue with the signal - good question for a harness guy maybe the swap harness has an issue ??

NW-99SS

iTrader: (6)

Might want to get rid of the MSD (MSR?) coil packs as well. They are not know for reliability/performance in the LS world. A set of 6.0l truck coils would work much better for you.

bayer-z28

iTrader: (14)

^ Yep. Needs to go to a tuner. Almost sounds like they put the intake/tb on there and didn't tune it. Those parts are money, so you got lucky. The MSD coils are debatable, but you can either run em till they die (and they probably will) or pick up a newer set of truck coils and sell the MSD's for $450.

I've picked up a lot of info to learn how to tune and it's a huge uphill battle. You really have to want it to stick with it. Learn one thing, and 25 other aspects pop up. Then you get into the newer ETC cars and you have to relearn almost the whole thing.

If you're in Amarillo, take it to Texas Speed. They're only an hour or two away, in Lubbock. They tuned my car in 2008 when I was living in NM. Call and make an appointment. It's prolly gonna take them a solid morning or afternoon, so have a buddy follow you out there.

V Clicky! V

Hoser66

Thanks guys for your info!!!! I will check on the shop in Lubbock for sure. But if anyone out there knows of one in Amarillo sure would work better for me. Lubbock is about 2 1/2hrs from me, Ama is 30min. Do you guys think it could be the ECU itself causing the prob? I can start it and the idle will be fine, drive it around for awhile and every thing is good. Start it the next day and the prob starts again with the high idle as soon as you touch the throttle. The idle will be high and then very slowly return to normal idle. Changed out the IAC and still got the same thing. Other words it comes and goes and you never know when it will happen.

alexus6798

iTrader: (24)

Try a TPS relearn..

Put keys in switch
Unplug TPS
Turn key to on position, wait 5 seconds
Turn key to off
plug TPS sensor back in
Start vehicle.

RacerXLs1

iTrader: (14)

U might be able to just send your computer in too get tuned. Give them a call they will set u up.