LS2 Running on 4 cylinders....Help!
10-16-2010, 04:21 PM
#1
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LS2 Running on 4 cylinders....Help! Was hoping this would go smoother....
First fire up and ....it fires immediately but 2 header tubes on one side and 2 or 3 on the other bank are cold. DBW pedal is dead also.
Background:
2006 GTO LS2 (24X) in a 67 Nova. bone stock other than a cam change.
Harness by Current performance
ECU is new unused E40 and flashed by Wait 4 me.
Pedal is Corvette dbw
A couple things:
- Fuel pressure is rock steady at 58 lbs on the rail gauge
- Thought maybe it needed o2's so I hooked them up (still open headers though)
- Checked all connections to injectors/sensors/etc.
- Pulled one plug on a cold cylinder and cranked it over , PLENTY of spark
- alternator plug isnt hooked up (but obviously power is) and there is no water in the motor as this was just a harness/ecu test
Jesse did say if the pedal was dead he would have to try another program but why is it only firing certain cylinders??????
Anyway to test injector firing without a scan tool?
I'll have to call Jesse and Jared on Monday but hoping I can narrow this down a little... any ideas guys???
First fire up and ....it fires immediately but 2 header tubes on one side and 2 or 3 on the other bank are cold. DBW pedal is dead also.
Background:
2006 GTO LS2 (24X) in a 67 Nova. bone stock other than a cam change.
Harness by Current performance
ECU is new unused E40 and flashed by Wait 4 me.
Pedal is Corvette dbw
A couple things:
- Fuel pressure is rock steady at 58 lbs on the rail gauge
- Thought maybe it needed o2's so I hooked them up (still open headers though)
- Checked all connections to injectors/sensors/etc.
- Pulled one plug on a cold cylinder and cranked it over , PLENTY of spark
- alternator plug isnt hooked up (but obviously power is) and there is no water in the motor as this was just a harness/ecu test
Jesse did say if the pedal was dead he would have to try another program but why is it only firing certain cylinders??????
Anyway to test injector firing without a scan tool?
I'll have to call Jesse and Jared on Monday but hoping I can narrow this down a little... any ideas guys???
10-16-2010, 07:52 PM
#2
$5 noid light "Injector Test Light" from Pep Boys will let you verify the PCM is pulsing the injectors. It's just a little button that connects to the harness in place of an injector, and flashes during cranking when the PCM pulses the injector.
You'll want to connect the alternator and have it charging while the engine is running...the gen-4 PCMs do strange things when batt voltage is low.
Assuming the engine is used, it's possible the injectors are stuck closed. It happens when they sit for long periods of time exposed to air, they corrode and won't open when pulsed.
You'll want to connect the alternator and have it charging while the engine is running...the gen-4 PCMs do strange things when batt voltage is low.
Assuming the engine is used, it's possible the injectors are stuck closed. It happens when they sit for long periods of time exposed to air, they corrode and won't open when pulsed.
10-16-2010, 08:27 PM
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Gonna try to borrow friends Modis (snap-on diag) tomorrow
The engine has sat for three years now so the inj's may well be the prob... any way to "free them up" ???
Alt will have to stay unplugged for now but the batt is new and the charger is hooked up also putting out plenty of amperage.
The engine has sat for three years now so the inj's may well be the prob... any way to "free them up" ???
Alt will have to stay unplugged for now but the batt is new and the charger is hooked up also putting out plenty of amperage.
10-16-2010, 08:42 PM
#4
I got a cheapo $20 injector tester a while back that connects to the battery, connects to the injector, and can select between single pulse test or multi-pulse test. You hear the injector click when tested, which tells you the pintle has opened and shut.
The multi-pulse test has been useful for breaking stuck injectors loose in the past, after soaking them in PB Blaster shot into both ends of the injector and letting it sit for a few minutes.
For $10 or so per injector, there are shops you can send your injectors to have them flow tested and cleaned. cruzinperformance.com has done injectors for me in the past and they do great work.
The multi-pulse test has been useful for breaking stuck injectors loose in the past, after soaking them in PB Blaster shot into both ends of the injector and letting it sit for a few minutes.
For $10 or so per injector, there are shops you can send your injectors to have them flow tested and cleaned. cruzinperformance.com has done injectors for me in the past and they do great work.
10-16-2010, 09:03 PM
#5
When my engine was only firing on one side........it was my PCM that got fried....because my PCM-to-engine "ground wire" was loose.
Thought I'd throw that out there, it was one of those things that nobody thinks of.
.
Thought I'd throw that out there, it was one of those things that nobody thinks of.
.
Last edited by LS6427; 10-16-2010 at 09:24 PM.
10-17-2010, 12:45 PM
#6
His is failing to fire on portions of both banks, so that rules out quite a few common causes such as what you brought up.
10-17-2010, 03:05 PM
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OK hooked up the Snap On Modis and did the following,
Checked codes p0606 pcm processor integrity fault
Several APP codes (hi and low, 1 & 2) (throttle pedal I assume)
Injector buzz test . Perfect and pcm is firing the correct injectors also pulled each injector and they look new. They are ALL getitng a strong 12 volts but as soon as the engine fires they are not being pulsed anymore. Except for the cylinders #5 and #4.
Cranking voltage to pcm test . Good at 12.09 V then jumps to 13
Checked crank sensor when fired it shows correct rpm
Checked cam sensor ......... little to NO signal (hows it firing 2 cylinders???)
Checked pedal voltage range APP1 and APP2 both seem to range but shows NO full throttle AND the throttle body doesnt react at all
SO heres what I think.....
1- the Vette pedal is causing an issue with the E40 gto ecu
2- the injectors are fine and the ecu (when commanded from the Modis) fires them perfectly
3 - The engine originally had a factory cam harness extension that I had to take off to plug in the Current Performance harness BUT I did check each of the three wires and they didnt cross inside the short extension. Maybe its still not getting the 12v to the correct terminal though and I need to figure out which pin is which on the sensor itself......the ecu IS sending 12v to the plug.
4- I HOPE the ecu isnt fried but it seems to show all the correct info on the scanner....
Checked codes p0606 pcm processor integrity fault
Several APP codes (hi and low, 1 & 2) (throttle pedal I assume)
Injector buzz test . Perfect and pcm is firing the correct injectors also pulled each injector and they look new. They are ALL getitng a strong 12 volts but as soon as the engine fires they are not being pulsed anymore. Except for the cylinders #5 and #4.
Cranking voltage to pcm test . Good at 12.09 V then jumps to 13
Checked crank sensor when fired it shows correct rpm
Checked cam sensor ......... little to NO signal (hows it firing 2 cylinders???)
Checked pedal voltage range APP1 and APP2 both seem to range but shows NO full throttle AND the throttle body doesnt react at all
SO heres what I think.....
1- the Vette pedal is causing an issue with the E40 gto ecu
2- the injectors are fine and the ecu (when commanded from the Modis) fires them perfectly
3 - The engine originally had a factory cam harness extension that I had to take off to plug in the Current Performance harness BUT I did check each of the three wires and they didnt cross inside the short extension. Maybe its still not getting the 12v to the correct terminal though and I need to figure out which pin is which on the sensor itself......the ecu IS sending 12v to the plug.
4- I HOPE the ecu isnt fried but it seems to show all the correct info on the scanner....
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10-18-2010, 10:17 AM
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Spoke with "the tuner".... he said its because I have a vette pedal and need the gto one and its causing it to go into shut down.
Heres the question though.....why not use a E40 Vette program to begin with? Is it ecu/vehicle specific? The ecu I sent him was new with NO flash whatsoever in it.
Anyway now my expensive custom harness has the wrong plug on the end of it if I do switch to a gto pedal....ugh.
Heres the question though.....why not use a E40 Vette program to begin with? Is it ecu/vehicle specific? The ecu I sent him was new with NO flash whatsoever in it.
Anyway now my expensive custom harness has the wrong plug on the end of it if I do switch to a gto pedal....ugh.
10-23-2010, 11:56 AM
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Update...... Got a brand new LS2 GTO pedal from GM. Thankfully the pedal portion of the harness was pigtailed so Current Performance sent me a GTO plug lead.
Plug the GTO pedal in.....and..... same exact thing. Fires instantly on all eight for one second and then all but two cylinder stop INJECTOR firing.
Now i'm getting a bit ....miffed.
Plugged my test light into a couple injectors AGAIN and it flases BRIGHT twice and goes dead... no more injector pulsing.
Checked throttle body operaton.....NOTHING.... TB blade DOES NOT react to pedal even with the GTO pedal.
Sure sounds like an ecu/programming issue to me whudda you guys think??
Plug the GTO pedal in.....and..... same exact thing. Fires instantly on all eight for one second and then all but two cylinder stop INJECTOR firing.
Now i'm getting a bit ....miffed.
Plugged my test light into a couple injectors AGAIN and it flases BRIGHT twice and goes dead... no more injector pulsing.
Checked throttle body operaton.....NOTHING.... TB blade DOES NOT react to pedal even with the GTO pedal.
Sure sounds like an ecu/programming issue to me whudda you guys think??
10-23-2010, 12:30 PM
#11
Plug the GTO pedal in.....and..... same exact thing.
Either develop your own ability and tooling to diagnose, or find another tuner to do it for you.
10-23-2010, 01:21 PM
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Agreed... when I say "tuner" Im referring to W4M who took the new, "unprogramed" e40 ecu and was supposed to supply something that was close to a stock LS2 (with cam) tune.
Would you agree this is ECU related ??
I mean the harness seems to be doing everything correctly... powering all sensors and injectors, pump etc.
Would you agree this is ECU related ??
I mean the harness seems to be doing everything correctly... powering all sensors and injectors, pump etc.
10-23-2010, 07:01 PM
#14
do you have 12v at each injector with the key in the on position?
the ECM provides a ground which enables each injector.
I assume you made certain the throttle body connector is connected firmly.
Sometimes the GTO LS2 ECM is difficult to remove VATS. I would verify that has been accomplished, perhaps someone is near with HPtuners.
My guess is that you have 2 issues.
1) VATS is not diabled
2) TB???
the ECM provides a ground which enables each injector.
I assume you made certain the throttle body connector is connected firmly.
Sometimes the GTO LS2 ECM is difficult to remove VATS. I would verify that has been accomplished, perhaps someone is near with HPtuners.
My guess is that you have 2 issues.
1) VATS is not diabled
2) TB???
10-24-2010, 08:10 AM
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Yes - 12 V at every injector
Checked every sensor connection 3x
Anyway to test the TB operation? Will a bad TB throw the APP codes?
Does VATS disable fuel? ( I read it disabled spark )
By the way anyone with the ability to diagnose and corect this in the Detroit area would be GREATLY appreciated and compensated . But the car isnt moveable right now.
Checked every sensor connection 3x
Anyway to test the TB operation? Will a bad TB throw the APP codes?
Does VATS disable fuel? ( I read it disabled spark )
By the way anyone with the ability to diagnose and corect this in the Detroit area would be GREATLY appreciated and compensated . But the car isnt moveable right now.
Last edited by Durney; 10-24-2010 at 08:25 AM. Reason: added text
10-24-2010, 08:49 AM
#16
I believe VATS on Gen IVs disable fuel and spark. Again it seems sometimes VATS is not easily disabled.
http://www.hptuners.com/forum/showth...highlight=vats
http://www.hptuners.com/forum/showth...highlight=vats
http://www.hptuners.com/forum/showth...highlight=vats
http://www.hptuners.com/forum/showth...highlight=vats
10-24-2010, 02:53 PM
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Key on ..probed the Throttle Body plug... with the GTO pedal
L to R and top to bottom as follows:
b/w - (nothing) yellow - 12.5v brn - 12.5v
purple - bouncing 3.7 to 4.7 v bl/blk - 5.0v grn - .016v
at each probe I actuated the pedal and saw no change in any value.
L to R and top to bottom as follows:
b/w - (nothing) yellow - 12.5v brn - 12.5v
purple - bouncing 3.7 to 4.7 v bl/blk - 5.0v grn - .016v
at each probe I actuated the pedal and saw no change in any value.
02-16-2013, 08:29 PM
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dont know how old this thread is but on my ls1 swap into a 1998 mustang.
it was the driver side that was cold! my car felt fast as it was on 4 cyl. lol
but any ways and dont know how my harness for the coil packs were flipped!
ex: the plug (the big white one) from the engine harness to the coil pack harness only going on one way right.
so lets say we are standing on the driver side looking at the motor. from.left to right it will be
1'2'3 and 4. so just swap the coil harness around.
so what before was 1 it will now be 4
what before was 2 will now be 3
what before was 3 will now be 2
what before was 4 will now be 1
and start that bad boy up!
oh and word of advise dont touch the headders. ur fingers will melt off. lol thats what happened to me. my finger prints hot stuck on the headders! lol and didnt have finger prints till about 3 weeks.
hope this help. it did for my and found the answer here on ls1 tech and a friend helped me out
it was the driver side that was cold! my car felt fast as it was on 4 cyl. lol
but any ways and dont know how my harness for the coil packs were flipped!
ex: the plug (the big white one) from the engine harness to the coil pack harness only going on one way right.
so lets say we are standing on the driver side looking at the motor. from.left to right it will be
1'2'3 and 4. so just swap the coil harness around.
so what before was 1 it will now be 4
what before was 2 will now be 3
what before was 3 will now be 2
what before was 4 will now be 1
and start that bad boy up!
oh and word of advise dont touch the headders. ur fingers will melt off. lol thats what happened to me. my finger prints hot stuck on the headders! lol and didnt have finger prints till about 3 weeks.
hope this help. it did for my and found the answer here on ls1 tech and a friend helped me out
12-05-2016, 12:39 AM
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Did You Ever Find Out What The Problem Was?????
