6.0 conversion runs pig rich
05-11-2009, 10:03 PM
#1
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
6.0 conversion runs pig rich I'm finishing up my thirdgen 6.0 project and I just got it started up this weekend. It starts but dies and the only way to get it to run is to hold the throttle down about 25%. Even then it's rich as hell. Here's a little background:
Motor is a 11:1 6.0 milled 243 heads custom cam headers LS6 intake.
Wait4me did the tune on it and I did the harness mods. I installed the computer from my other 6.0 conversion (71 Vette) and it runs the same. I put the Camaro computer on the Vette and it started right up but was way rich. Probably because the Vette has 50lb injectors and the Camaro tune is for 42s. The Vette is also Speed Density where the Camaro is MAF. Since the Camaro comp ran the Vette and the Vette comp won't run the Camaro any better I don't think it's the tune.
I have fuel pressure set correctly at 58psi. I did get the Camaro to run semi decent at 20psi fuel pressure, that's how rich it is.
I tried a known good MAF and it didn't make a difference. I also tried the TPS off the Vette and it made no difference either. I unhooked both O2s with no results. All sensors are plugged in. I don't have a code reader unfortunately.
Could I have screwed something up when I redid the harness? The harness I did for the Vette works great so I'm not sure that's it. Is there a sensor that could be bad causing this problem?
Motor is a 11:1 6.0 milled 243 heads custom cam headers LS6 intake.
Wait4me did the tune on it and I did the harness mods. I installed the computer from my other 6.0 conversion (71 Vette) and it runs the same. I put the Camaro computer on the Vette and it started right up but was way rich. Probably because the Vette has 50lb injectors and the Camaro tune is for 42s. The Vette is also Speed Density where the Camaro is MAF. Since the Camaro comp ran the Vette and the Vette comp won't run the Camaro any better I don't think it's the tune.
I have fuel pressure set correctly at 58psi. I did get the Camaro to run semi decent at 20psi fuel pressure, that's how rich it is.
I tried a known good MAF and it didn't make a difference. I also tried the TPS off the Vette and it made no difference either. I unhooked both O2s with no results. All sensors are plugged in. I don't have a code reader unfortunately.
Could I have screwed something up when I redid the harness? The harness I did for the Vette works great so I'm not sure that's it. Is there a sensor that could be bad causing this problem?
05-11-2009, 10:15 PM
#2
Check MAP sensor and connection
Its hard to say what the problem is with a mail order tune and no diagnostics.
If you can wait until the 24th I will be back in Hudsonville with HP Tuners, we can figure it out, it will cost $100 in credits though.
Ryan
Its hard to say what the problem is with a mail order tune and no diagnostics.
If you can wait until the 24th I will be back in Hudsonville with HP Tuners, we can figure it out, it will cost $100 in credits though.
Ryan
05-12-2009, 07:51 PM
#3
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
I hope I have it figured out before then but I'll let you know if I don't.
I'm surprised more people have not weighed in on this. I figured someone else would have had a similar issue.
I'm surprised more people have not weighed in on this. I figured someone else would have had a similar issue.
05-15-2009, 01:06 PM
#4
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
A little update: The excessive rich condition seems a little better now but it's still running like crap. I got it to idle somewhat last night and I got my IR heat gun out. The primary tubes on the odd side were all at normal temps (650), but the even side was all about half that.
I checked all the coil wiring from the pcm to the coil packs and it is all correct. I borrowed a set of coils and put them on with no change. I checked ground resistance and it was kind of high on both sides (20ohms). I redid some grounds and got it down to .5 ohm but it increases to 17ohm when the key is on. I think it's because the O2 ground ties in with the coil ground. I unplugged the O2s and the ground resistance goes back to .5ohms. I started it with the O2s unplugged and it runs the same as before. Will a normally good running motor run right if you unplug the O2s?
I also swapped the injectors with the 50s that are in the Corvette. I lowered the fuel pressure to compensate for the larger size. No difference.
My only hope now is that the plugs are fouled. I'm picking up a set of those today.
I checked all the coil wiring from the pcm to the coil packs and it is all correct. I borrowed a set of coils and put them on with no change. I checked ground resistance and it was kind of high on both sides (20ohms). I redid some grounds and got it down to .5 ohm but it increases to 17ohm when the key is on. I think it's because the O2 ground ties in with the coil ground. I unplugged the O2s and the ground resistance goes back to .5ohms. I started it with the O2s unplugged and it runs the same as before. Will a normally good running motor run right if you unplug the O2s?
I also swapped the injectors with the 50s that are in the Corvette. I lowered the fuel pressure to compensate for the larger size. No difference.
My only hope now is that the plugs are fouled. I'm picking up a set of those today.
05-16-2009, 07:12 PM
#5
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
New plugs didn't make a difference either. I put the 42s back in yesterday since they are not the problem and swapped the cam sensor for a known good one. It seemed to help at first but I'm not sure now.
It will start and idle now but if I rev it a little it dies. It's also not running smoothly. The header temps are closer from one bank to the other but the right bank is still a 100+ degrees cooler than the left bank.
Then I swapped the crank sensor for a known good one. Again, no change but now it seems like #2 is not firing at all.
Tomorrow I'm going to pull the harness out and ohm test all the wires and verify that each wire goes to the right place.
It will start and idle now but if I rev it a little it dies. It's also not running smoothly. The header temps are closer from one bank to the other but the right bank is still a 100+ degrees cooler than the left bank.
Then I swapped the crank sensor for a known good one. Again, no change but now it seems like #2 is not firing at all.
Tomorrow I'm going to pull the harness out and ohm test all the wires and verify that each wire goes to the right place.
05-16-2009, 10:48 PM
#7
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
The MAP is good, the Corvette fired right up with it. I've swapped every sensor except the IAC.
Grounds are good on the harness. I'm praying that the harness is screwed because I'm completely out of ideas otherwise.
Trending Topics
05-18-2009, 07:17 PM
#9
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
I'm starting to think the same thing but I'm not sure.
It runs on the Corvette computer but won't idle and has a miss but all header tubes are the same temp. It's rich as hell and won't idle on the Camaro computer either and the right bank header tubes are 100-200 degrees cooler than the left bank.
I may have to take you up on your offer to help me out on this. I checked the entire harness yesterday and it is correct.
It runs on the Corvette computer but won't idle and has a miss but all header tubes are the same temp. It's rich as hell and won't idle on the Camaro computer either and the right bank header tubes are 100-200 degrees cooler than the left bank.
I may have to take you up on your offer to help me out on this. I checked the entire harness yesterday and it is correct.
05-18-2009, 08:38 PM
#11
Teching In
Join Date: Apr 2008
Location: PA
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
hi i know it sound stupid but did you check for bad vac leaks . The ECM may be trying to correct the lean condition. What is the map read at key on engine off and what is it at idle.
John
John
05-18-2009, 10:33 PM
#13
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
I don't have any scanning capacity right now so I don't know what the map is reading.
I'm going to check for vacuum leaks but I don't think that is it. I think I'd hear it
05-19-2009, 10:30 PM
#16
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
For the $500+ that would cost I could get a tuner and do it myself so that's out.
05-30-2009, 05:25 PM
#18
Launching!
Thread Starter
iTrader: (6)
Join Date: Jan 2005
Location: Hamilton, MI
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
The main problem was the injector size in the tune. I forgot to tell Jesse at Wait4me that I had 42s in this motor. The excessive fuel took out two sets of spark plugs and at least one probably both O2 sensors. Ryan came over twice and we tuned it with his HP Tuners. Big thanks to him!
It's not perfect yet but it's a lot better. New spark plugs are in along with replacement O2s. The oil was pretty thin so I changed that too. It's finally off the jack stands!
It's not perfect yet but it's a lot better. New spark plugs are in along with replacement O2s. The oil was pretty thin so I changed that too. It's finally off the jack stands!
