lq4 in a jeep cj
02-11-2012, 11:05 AM
#1
Teching In
Thread Starter
iTrader: (1)
Join Date: Nov 2011
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
lq4 in a jeep cj I've been fighting my 6.0 swap for about a week now, it cranks fine but doesn't start.
This is a 2004 lq4 out of a 2500hd it is dbw.
Originally it was giving a code U0107 but that seems to have been cleared up by charging the battery, the battery never seemed that low, it always cranked fine but never the less charging the battery made the code go away and it has not shown any other codes at all.
Real time data shows throttle position of 19.6% and moves to 99.8% with the peddle floored, rpm goes from 0 to 186 at crank speed, timing moves from 0 to 13 deg advance at crank. Coolant temp, map, iat all seem to be reading in a normal range. It is still showing 4 o2 sensors even though the tunner removed the 2 post cat sensors, don't know if that's normal?
Pulled a plug wire and there is no spark, I can smell some fuel sometimes not always. Checked and double checked power and grounds. Ran the troubleshooting tree in the GM manual for no spark, it had me use a test light at each coil connector between the power wire and the ground, then between the power wire and ref low, that all checked out good. Now it wants me to replace the coils but I don't think all 8 of them are bad? I guess there is no way to check the ign ctrl wire for a signal?
Over the past week I've probably tried to start this engine 100 times and 1 time, 1 time only when I had a piece of wire in a spark plug lead checking for spark the enging started for about 3 seconds, the spark was awsome but I haven't been able to get it to fire again.
I'm at a dead end, don't know what else to check. If you have any suggestions or can offer any advice I'd sure appreciate it.
If anyone has a 2003-2005 chevy truck with a drive by wire v8 that we could put this computer in to see if it works that would be great. I'm in tulsa oklahoma.
This is a 2004 lq4 out of a 2500hd it is dbw.
Originally it was giving a code U0107 but that seems to have been cleared up by charging the battery, the battery never seemed that low, it always cranked fine but never the less charging the battery made the code go away and it has not shown any other codes at all.
Real time data shows throttle position of 19.6% and moves to 99.8% with the peddle floored, rpm goes from 0 to 186 at crank speed, timing moves from 0 to 13 deg advance at crank. Coolant temp, map, iat all seem to be reading in a normal range. It is still showing 4 o2 sensors even though the tunner removed the 2 post cat sensors, don't know if that's normal?
Pulled a plug wire and there is no spark, I can smell some fuel sometimes not always. Checked and double checked power and grounds. Ran the troubleshooting tree in the GM manual for no spark, it had me use a test light at each coil connector between the power wire and the ground, then between the power wire and ref low, that all checked out good. Now it wants me to replace the coils but I don't think all 8 of them are bad? I guess there is no way to check the ign ctrl wire for a signal?
Over the past week I've probably tried to start this engine 100 times and 1 time, 1 time only when I had a piece of wire in a spark plug lead checking for spark the enging started for about 3 seconds, the spark was awsome but I haven't been able to get it to fire again.
I'm at a dead end, don't know what else to check. If you have any suggestions or can offer any advice I'd sure appreciate it.
If anyone has a 2003-2005 chevy truck with a drive by wire v8 that we could put this computer in to see if it works that would be great. I'm in tulsa oklahoma.
02-11-2012, 03:11 PM
#2
Teching In
Thread Starter
iTrader: (1)
Join Date: Nov 2011
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Ok found the problem, I'm using three fused circuits to power the ecu and sensors, they all had power with the key in the run position but only two had power with the key in the start position.
