Need Help, Swap fires but doesn't idle
08-15-2009, 04:44 PM
#21
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Well, my harness and PCM are from a truck so I had to remove 2 of the altenator wires and only use wire B (which was the red wire I believe) for my 2001 Z28 Altenator. Plugged it in yesterday and tried starting the car, but no change with the pedal.
Funny thing is, I had to move the car around earlier and if you start the car and put it in gear real quick it will move just because of the rev of the engine, but it seems to stay started a few seconds longer as well.
Funny thing is, I had to move the car around earlier and if you start the car and put it in gear real quick it will move just because of the rev of the engine, but it seems to stay started a few seconds longer as well.
08-15-2009, 04:45 PM
#22
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Oh, and my battery is brand new. I even have a bettery charger hooked up to it, just because I spent so much time turning the engine over in the last couple of weeks, diagnoising my issues.
08-18-2009, 08:49 AM
#23
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Update!!!!!! Well, it looks like I made some improvement but something is still a miss. I picked up a MAF yesterday on my lunch break and spent some time wiring it up last night in between my 1 year old crying. I wired my MAF pigtail into the PCM with the exception of the pink 12v wire. I didn't have a good place to splice the pink wire into, with the harness still in the car so I just ended up sliding it into the positive battery terminal clamp for a temporary solution.
Started the car up this morning and she now holds a steady idle, but she idles at around 2000 RPMs and I still don't have any throttle control. Checked the PCM with a scanner and still no codes. I only let her idle for about 20 to 30 seconds because it was 8:00am in the morning and I didn't want to bother my neighbors. Any ideas??
Also, I checked the oil earlier and noticed a gas smell on the dip stick. I'm pretty sure that this is a result of my engine not starting for a couple of weeks. I acutally had the 2 ignition coil harness plugs reversed so the engine wouldn't fire because it was fighting itself.
Started the car up this morning and she now holds a steady idle, but she idles at around 2000 RPMs and I still don't have any throttle control. Checked the PCM with a scanner and still no codes. I only let her idle for about 20 to 30 seconds because it was 8:00am in the morning and I didn't want to bother my neighbors. Any ideas??
Also, I checked the oil earlier and noticed a gas smell on the dip stick. I'm pretty sure that this is a result of my engine not starting for a couple of weeks. I acutally had the 2 ignition coil harness plugs reversed so the engine wouldn't fire because it was fighting itself.
Last edited by gjohnson; 08-18-2009 at 11:44 AM.
08-18-2009, 03:20 PM
#24
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Anyone???? I really need some help. I plan on checking vacuum lines when I get home. Anyone have a vacuum line diagram for the LS1, I'm not sure where to start.
08-18-2009, 06:23 PM
#25
Between the PCV, brake booster, and evap cannister purge there isn't much else sharing engine vacuum.
I'd change the oil rather than running gas-contaminated oil through the engine.
And I'd wire up the MAF properly including the 12VDC pin...address the glitches you know about and go from there.
I'd change the oil rather than running gas-contaminated oil through the engine.
And I'd wire up the MAF properly including the 12VDC pin...address the glitches you know about and go from there.
08-18-2009, 07:31 PM
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Ok, apparently I'm going to have to readdress the Steam vent issue, but can you let me know if I have my Vacuum lines setup ok. I found this diagram as well on line. Of course I'm running the LS1 intake, but I have a L33 truck engine.
My intake looks like this with 2 nipples at the back, but for some reason I only have 1 nipple up front on the passengerside and 1 on the driverside, then the 2 nipples bellow the throttle body.
1. Not connected, not sure where to run it
2. Connected to my brake booster
9. Crank case ventelation hoses is connected to the pass side nipple (labeled #7)
The PCV valve hoses that begins at the back of the Drivers head I have connected to the Driverside nipple on the opposite side of #7 at the front of the intake.
My intake looks like this with 2 nipples at the back, but for some reason I only have 1 nipple up front on the passengerside and 1 on the driverside, then the 2 nipples bellow the throttle body.
1. Not connected, not sure where to run it
2. Connected to my brake booster
9. Crank case ventelation hoses is connected to the pass side nipple (labeled #7)
The PCV valve hoses that begins at the back of the Drivers head I have connected to the Driverside nipple on the opposite side of #7 at the front of the intake.
08-19-2009, 02:03 PM
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Yeah, I plan on plugging # 1. I just confused about if my routing of the PVC line and Crank case ventilation will be ok or if I need to take a different approach.
08-19-2009, 06:19 PM
#30
I can't tell from your notes and the drawing how your PCV is plumbed, but two things are critical:
1.) The PCV valve (7) has to be connected **DOWNSTREAM** of the throttle blade, where it will have engine vacuum. It should be plumbed back to connection (10).
2.) The PCV vent (9) from the valve cover has to be connected **UPSTREAM** of the throttle blade, where it gets filtered and MAF-metered air but not full engine vacuum.
1.) The PCV valve (7) has to be connected **DOWNSTREAM** of the throttle blade, where it will have engine vacuum. It should be plumbed back to connection (10).
2.) The PCV vent (9) from the valve cover has to be connected **UPSTREAM** of the throttle blade, where it gets filtered and MAF-metered air but not full engine vacuum.
08-20-2009, 06:12 PM
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Oh, I think I have my idle issues solved but does anyone have any suggestions on where I should start on my throttle issues. Like I said, the throttle opens and closes when the key si switched to the Run position, but I have no other control. My Tuner is sending me another PCM so I can veiw the codes it may be throwing, but any ideas until that gets here?
08-21-2009, 08:06 PM
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I still need to hook up my VSS, Backup lights, and Lock out solenoid. I have to wire + 12v Key to the O2 sensors, wire in my PCM controlled radiator fans as well as I need to figure out how to wire in the cruise control functions.
The altenator belt is on and I think I have my altenator wiring complete. I'm running a 04 Truck PCM and harness, but a 2002 Z28 altenator. I was told in another thread that I had to remove 2 wires from the truck 3 wire setup, to run the F-Body altenator, but now someone else is telling me that's incorrect. That the PCM is looking for the 3 wire signal.
Right now the pedal opens and shuts when the key is turned to Run position but that's it.
The altenator belt is on and I think I have my altenator wiring complete. I'm running a 04 Truck PCM and harness, but a 2002 Z28 altenator. I was told in another thread that I had to remove 2 wires from the truck 3 wire setup, to run the F-Body altenator, but now someone else is telling me that's incorrect. That the PCM is looking for the 3 wire signal.
Right now the pedal opens and shuts when the key is turned to Run position but that's it.
08-21-2009, 08:35 PM
#34
Somebody else recently had similar problems with drive-by-wire not responding to pedal inputs, only after he completed the wiring including the alternator did it start working.
I dug it up for you:
https://ls1tech.com/forums/conversio...p-problem.html
He somehow found that if the PCM didn't see the alternator charging, the throttle was disabled. Possible your truck PCM is looking for an alternator output that it's not seeing because you went with F-Body alternator wiring?
I dug it up for you:
https://ls1tech.com/forums/conversio...p-problem.html
He somehow found that if the PCM didn't see the alternator charging, the throttle was disabled. Possible your truck PCM is looking for an alternator output that it's not seeing because you went with F-Body alternator wiring?
08-28-2009, 08:54 AM
#35
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Alright, what should I check now?????
My tuner sent me a new PCM with just the Vats and emissions removed. I've spent the last couple of nights lengthening my harness so that the PCM would have better placement in the passengerside foot well. Last night I got the harness back in the car and the PCM hooked up, I fired up the car this morning and let it idle for about a minute and I still have no response at all from the Gas pedal. The car dropped down and Idled at about 700 RPMs but after about 30 or 40 seconds it jumped back up and decided to idle around 1200Rpms.
I'm really looking for ideas here. I converted my altenator to the 1 wires setup, since I'm running a F-Body altenator. I have the Tac and Pedal hooked up and I can hear the throttle plate open and shut when the key is moved to the run position. I don't have any Tac, App 1 or App2 codes. What now????
Oh, and I PMed Speartech about my altenator wiring and setup and he confirmed that it should be correct. But shouldn't my pedal respond even when the engine is not running and the altenator is not charging?
I don't have a reliable multimeter, but I could borrow my neighbor's later on if I need to.
My tuner sent me a new PCM with just the Vats and emissions removed. I've spent the last couple of nights lengthening my harness so that the PCM would have better placement in the passengerside foot well. Last night I got the harness back in the car and the PCM hooked up, I fired up the car this morning and let it idle for about a minute and I still have no response at all from the Gas pedal. The car dropped down and Idled at about 700 RPMs but after about 30 or 40 seconds it jumped back up and decided to idle around 1200Rpms.
I'm really looking for ideas here. I converted my altenator to the 1 wires setup, since I'm running a F-Body altenator. I have the Tac and Pedal hooked up and I can hear the throttle plate open and shut when the key is moved to the run position. I don't have any Tac, App 1 or App2 codes. What now????
Oh, and I PMed Speartech about my altenator wiring and setup and he confirmed that it should be correct. But shouldn't my pedal respond even when the engine is not running and the altenator is not charging?
I don't have a reliable multimeter, but I could borrow my neighbor's later on if I need to.
Last edited by gjohnson; 08-28-2009 at 09:33 AM. Reason: More info
08-28-2009, 02:29 PM
#36
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Well, I did a little more research with my tuner and from what we can tell my PCM isn't even getting a signal from the TAC module or pedal. I am going to have to trace my plug wires back to the PCM and see what I'm missing.
On my lunch break I ran home and unplugged the gas pedal, started the Car and after about 25 senconds of running still no codes.
Then I disconnected the battery again, plugged the pedal in and unpluged the TAC module. Started the car and let her idle for 30 seconds or so and again still no codes.
On my lunch break I ran home and unplugged the gas pedal, started the Car and after about 25 senconds of running still no codes.
Then I disconnected the battery again, plugged the pedal in and unpluged the TAC module. Started the car and let her idle for 30 seconds or so and again still no codes.
08-28-2009, 05:07 PM
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I recently put a 2004 lq9 in a 56pickup and the throttle pedal wouldnt respond I had the gm dealer lookup the tac module and the junkyard gave me one for a 2006, turns out 03 to 05uses the sme one but 06 is different .My advice is double check the gm part #
08-28-2009, 09:11 PM
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I'm in business!!!!!! Gas pedal is working, problem solved. Apparently I had a couple of broken wires on the TAC plug that was giving my all my issues.
Now I just have to wire up my electric fans and I can finally take her for a test drive. Of course I'm going on a road trip in the morning so it looks like it will be Tuesday before I can put her on the road.
Now I just have to wire up my electric fans and I can finally take her for a test drive. Of course I'm going on a road trip in the morning so it looks like it will be Tuesday before I can put her on the road.
