i've recently done a ls1 5.7 swap into my 2001 chevy pickup. now, i ask this question on LS1Tech because i think these are engine issues, not truck side, and that is the site to go to for LS1 questions, right? welp...that didn't work. So i'm wondering if any experts here can help...maybe point me to a shop in San Antonio that can run a diaginositic or something?

What i have:
2001 silverado (use to be 4.3)
2001 z28 Ls1 engine, accessories
truck 4l60e
truck TQ (from 4.3)
Custom built wiring harness
Z06 MAF
first of a line intake


here's the list of problems i'm having:

1. rough idle
2. when shifting from drive to reverse (or other way around) i have to sit it in nuteral for a bit...cuz the truck will rev up real high, 2000 rpm - 3000 rpms, between those shifts
3. there is a "flat spot" i get when driving. usually between 40 mph and 50 mph...i can stomp on the gas and it won't down shift....it'll stay in 4th gear. but i don't have to stomp on it to do it..it'll "bog out" just normal driving too. this happens only about 75% of the time. the rest of the time it'll shift and accelerate fine.
4. code p0121
5. MAP sensor reading flat, like 13.6 or something constantly

here's what we've tried:

replace tranny, but not TQ
Hours of re-tuning to try to see if it's a tuning issue
replaced the TPS

What we think it might be:
Trottle Body
Map Sensor
TQ

 

Damn Onyx, you've had that LS1 in there for a while now. I figured you had that thing running top notch.
What PCM are you using, the one from the 4.3 or the LS1?

When I put my LS1 in, the idle was bad for a while. I put a tune from a 6.0 in for the time being and that helped it out a lot from dieing.
Now I have gotten a dyno tune so thats not an issue anymore.

Unless you have a bad sensor somewhere, my guess is that your tune is way off for that size motor.

 

call allen nelson ...he's in sa and he has done the ls1 swap in his truck before.he's also a sponsor and his number is to the right>>>>>>>

 

bud8 beat me to it. talk to allen and see what he thinks. theres also a ls1 swap section in his forums over at LS1truck. lots of info and some very knowledgeable guys over there.

 

Allen Nelson at Nelson Performance will fix you up he cured all my driveability issues with my truck until I blew it up.

His number is 210-626-0278

 

and...of course....Nelson doesn't answer the phone. you know, i've probably tried to call him 10 times over the months...and i've never once got to talk to anyone on that number.

 

did you leave a message with your ##? have you tried e-mail? if so i dont know what to tell ya

 

Sometimesh he can be hard to get ahold of. PM me your number. Ill give it to him when I talk to him about a few options for my new motor build and see when he is going to have the dyno back up and running to dyno the new setup.

 

yes i did...and i've left it before too. of course, i left my phone at home today

 

hahah, you know hes guna finally call today then