any other lsx gurus out there

[nofxrxmxpx]

I ran the car out at a spot a couple weeks ago and all went well, driving it back to the meet spot cruising along the car sputtered and died... While it was sputtering to a low ide it had no throtle response whatsoever. we trailored the car back home and just got around to trying to solve the problem.

My tuner and I checked the codes and there were no CEL's whatsoever. I made sure there was gas in it, it has fuel, spark.. When i crank it it is very hard to get running but once running it idles at 100-400rpm had has NO throtle response whatsoever then 2-5 seconds of poor idle and it dies. I have no idea where to look next. I need to get this thing fixed

[nofxrxmxpx]

for anyone who isnt away of the setup it is an ls1 with bolt ons and some juice tuned to the T on HPtuners

also, please move this to tech, im a dumbass.

[Dredz172]

this happened to me once, the throttle cable slipped off of the throttle body, so when I pushed the gas, it wouldn't move the butterfly inside the throttle body, and thus no throttle response.... in the pictures you can see on the right side of where the cable is, there is some scoring where the throttle cable slipped outside of the little retainer for it...... when it happened to me, I was WOT, and it stuck WOT for about a second or two, the cable slipped off, and then the engine slowed down and died, and I lacked all throttle response
http://i33.photobucket.com/albums/d69/dredz172/CIMG2274.jpg
http://i33.photobucket.com/albums/d69/dredz172/CIMG2273.jpg

just an idea, hope your fix is as quick and easy as mine was

[Patrick]

This may sound dumb, have you checked your grounds?

[nofxrxmxpx]

stay out of my thread. Partrick and Mhiggs your ideas are terrible

Dredz- The throttle cable is A-ok, i can start it up and have my brother push open the throttle manually and nothing if barely anything happens.

[Patrick]

Partrick and Mhiggs your ideas are terrible

I really hope you're joking.

[PipeLayaz]

I take it you've already posted your concern on LS1tech.com? My 2 Trans Ams being so low on miles I never had an engine/tranny problem before so I really don't have much trouble shooting idea's for you. I know LS1tech would be my first place to go though... hope you figure it out man.

[pat94cobra]

you say you have fuel. Do you know how much pressure you have and how much your supposed to have. try to start it with starting spray. Pulse the spray like 1 spray per second. If it doesnt run its not fuel related. Also you have spark, do you have injector pulse? I think bryant (01 cobra) had a injector pulse tester. Thats all I can think of right now.

[Greg Kulbick]

I really hope you're joking.

Are you suggesting your ideas are typically stellar?

[slmdLS1]

no fuel pressure would throw a code, would it not? at the least, a misfire code?

[Dustin]

it's almost sounding like a vacuum leak, but i don't know. I'd start checking all of the hoses if you haven't yet.

[Tally TransAm]

vacuum leak

[redmach1]

I am with pat94cobra. You need to make sure you have the correct pressure and go from there. I have seen a 5psi reduction in pressure cause similar problems.

[sstony]

all that or start swapping out TPS or IAC

[Patrick]

Are you suggesting your ideas are typically stellar?

No, I'm suggesting covering all bases.

[Riceman]

If not a vacuum leak, try pulling the harness to the MAF and/or TPS. I doubt the TPS could cause this issue unless it's REALLY trashed though, as "closed" or "0" is reset every time the car is powered on, and if the PCM reads a lower voltage during operation than it read at power-on, it resets "closed" to be the new lowest voltage read.

Yes, the car should start and run (poorly) without both MAF and TPS. It will be in a bad version of SD.

[nofxrxmxpx]

If not a vacuum leak, try pulling the harness to the MAF and/or TPS. I doubt the TPS could cause this issue unless it's REALLY trashed though, as "closed" or "0" is reset every time the car is powered on, and if the PCM reads a lower voltage during operation than it read at power-on, it resets "closed" to be the new lowest voltage read.

Yes, the car should start and run (poorly) without both MAF and TPS. It will be in a bad version of SD.

+1... i have a good list of shit to look through, good thing the ls1 only has like 2 vaccume lines, and yes i posted on tech. belive it or not i got more of a reply on here. Fixing a car by yourself isnt bad it just takes long, fixing a car with the help of a message board makes life easy, hopefully it is something simple like a MAF problem or a Vac leak, Thanks for the replys

[slmdLS1]

If not a vacuum leak, try pulling the harness to the MAF and/or TPS. I doubt the TPS could cause this issue unless it's REALLY trashed though, as "closed" or "0" is reset every time the car is powered on, and if the PCM reads a lower voltage during operation than it read at power-on, it resets "closed" to be the new lowest voltage read.

Yes, the car should start and run (poorly) without both MAF and TPS. It will be in a bad version of SD.

im not sure thats entirely true. i monitor my TPS with the car on and off and it reads .8% or 1.6%, and its never been reset, until tony did it via a tune(i think)...then again i messed with the idle screw after the motor was done, and refuse to touch it again.

[sstony]

when my battery was bad, my TPS would not get a good voltage and my car never idled.

[nofxrxmxpx]

i took the intake off it today and the plugs out... Intake was fine crackwise, MAP sensor was in correctly and all vaccume lines were hooked up properly.

The plugs were covered in fuel and are very fouled. I dont think the plugs fouling was the cause of it running shitty something went wrong to make the plugs foul. I will throw another set in, Double check everything when i reinstall the intake and see where i am from there.

[Gt]

Check the ECT sensor, on a ford if the ECT sensor goes bad it can cause it to run rich as hell.

[nofxrxmxpx]

not farmiliar with this sensor. It might be called something different on the chevy motors. What does it stand for and what does it do.

[Mhiggs]

Its the engine coolant temp. sensor.

[nofxrxmxpx]

Mine is fine. On the ls1 it actually controlls timing, its one of the first thing i looked at. If it is faulty or not pluged in it will run the car in a limp mode with very low timing, the car does not want to run period so i am assuming something otherwise.

[Benjamin]

you don't think that something in your nitrous system caused the plugs to foul..... like maybe a faulty fuel solonoid? could have leaked a good lil bit and made them initially foul...

[v8minus2]

or could be stuck open completly. flooding the car everytime the ignition is turned on.

[nofxrxmxpx]

that was the 2nd thing i checked.... the nitrous syterm checked out OK. fuel solonoid is fine.

[SS2win]

ru in tally?

[SATAN]

With Dustin's software you should be able to look at your pids for each sensor. You need to take a look at them and start looking for one that is out of range. You need to run down the sensor list and look at all of them. One other thing you also need to check is your 5V reference signal. Most of the sensors on your engine run off of a 5V reference signal, if you are getting less or more than 5V your sensor could be reading in range but the computer won't think it is due to your ref. sig. being off.

[nofxrxmxpx]

yes i am in tally..


And lloyd, good advice. I would have already done this on my old motors software but i dont know shit about HPtuners i leave the tuning to D. I will call him this week after i get a new set of plugs in it and run a few more simple tests.