Need check/tune on bare bones LQ4 in a rockcrawler in Sac Area

[YJ_OVER_SJ]

already posted in LS1Tech but don't know how focused they are on rock crawlers over there.

Anyone in the Sacramento area that does tunes on the LR4(4.8L vortec basically same engine as LS1)? Need someone who can get it running right for wheeling needs and can make sure it's programmed correctly to get rid of all the sensor checks that got removed when it was dropped in to a competition rock crawler.

Right now it's running super rich, won't hold idle when cold, has almost no power(acts like it's miss-firing) from a stop. once it gets the rpms up, it's a bit better.

setup: LR4 stripped down with Fast Chip Computer Flash, Current Performance Engine Harness, powerglide 2speed, atlas 3.8, pushing 35" tires with 4.88 gears.

I know the powerglide isn't very low end but the 4.88 gears and 35" tires shouldn't be dragging that much. like I said, getting going from a stop feels like it's just pouring fuel out the tailpipe running on 4 cylinders.

Oh, and I like to learn so if someone likes to talk and teach while they check and tune or doesn't mind a side-kick grease monkey, even better.

EDIT: Damn acronyms. thanks for clarifying, changed it from LQ4 to LR4. It is a LR4 4.8L

[Lil'John]

Not much help, but you do know that LQ4 is the regular 6.0L engine while LR4 is the 4.8L, right?

Not sure what ill effects would happen if you used the tune from a 6.0L on a 4.8L engine but if you did that, there might be a problem

I'm sending my LQ4 PCM over to Nelson Performance once I get it all running

[florida4x4]

try pm'ing wait4me on ls1tech

[mudmandan]

Some one at Monodax MXScan (Tunercat / Jet DST) OBDII Support
could tune it for you, or if you like reading, the information to DIY is
there also.(you would need the jet DST or other tuning sowfware to DIY)


http://www.monodax.com/forums/

[YJ_OVER_SJ]

Originally Posted by Lil'John

Not much help, but you do know that LQ4 is the regular 6.0L engine while LR4 is the 4.8L, right?

Not sure what ill effects would happen if you used the tune from a 6.0L on a 4.8L engine but if you did that, there might be a problem

I'm sending my LQ4 PCM over to Nelson Performance once I get it all running

You're absolutely correct. My mistake. It's an LR4.

[YJ_OVER_SJ]

btt.

I just got the oil pan replaced and the MAF and throttle body cleaned up. The engine fired up and idled perfectly. I only let it run for a couple minutes and then shut it off. I took it down to the carwash to get the leaky oil cleaned off the engine and then took it home. when I tried to fire it up again, the fuel pump wouldn't turn on. fidgetted with a few wires(map sensor, oil guage, tps, knock sensor. then turned the ignition over again and it started right up and idled well. pumped the gas while it was running and it backfired a few times, acted like it was dumping too much fuel or was pre-igniting or something, and then after a couple pumps of the gas pedal, the engine shut itself off. when trying to turn the ignition over again, the fuel pump turned on but the engine wouldn't start(spark turned off?) turned ignition off and then back on, fuel pump would not turn on either.

This is an identical problem I was experiencing when I cracked the oil pan. I don't know if it originally recognized low oil pressure when I was pumping the gas and it was drowning itself? but the computer is now pissed. I bought an ODBII reader but there's something wrong with the ODBII port so I can't get codes.

[florida4x4]

If you're having to mess with wires to get it to run then you need to go over everything and fix it. EFI don't play well with bad connections/grounds/etc. you'll be chasing your tail until you have the wiring sorted out...