RCSConstruction
Chief Petty Officer
- Joined
- Mar 23, 2007
- Messages
- 549
I recently found a 2000 L29 7.4l replacement motor for my truck (1997 Chevy Silverado 3500 SRW) It was in a wrecked truck exactly like mine with 29,000 miles. We replaced all the gaskets in the motor and used most of the original sensors. The only sensors used off the old motor were the oil pressure sensor and MAF. The truck spits out two codes. 102 and 340. Low voltage MAF, shows ZERO on scanner but has voltage going to it. The other is a cam sensor that was cleared but then came back. You can pull just about any sensor on the truck and it will not run any different. Maf,Dist.,knock,O2, Even a spark plug wire!!! I swapped out MAF's with no change. Can't get to the camshaft sensor and don't want to unless you think it is the culprit.
The truck smells heavy of raw gas, spits raw gas out of a small exhaust leak where the cat attaches to exhaust and has an extremely erratic idle. It also has no power and backfires hard enough to sound like my muffler is self destructing inside.
I have spent a grand getting it analyzed and worked on with no difference. The dealer will not touch it since the longblock is from a 2000.......... I can't imagine the year model number is the culprit? Different ecm program? I am at a loss.
Thanks for any insight
P.S.
What was wrong with the old motor you ask? NOTHING.... LOLOLOL it had 140,000 on it and a tap in the valve train but no problems. I just wanted to get a new motor in so I didn't have any issues later down the road.
The truck smells heavy of raw gas, spits raw gas out of a small exhaust leak where the cat attaches to exhaust and has an extremely erratic idle. It also has no power and backfires hard enough to sound like my muffler is self destructing inside.
I have spent a grand getting it analyzed and worked on with no difference. The dealer will not touch it since the longblock is from a 2000.......... I can't imagine the year model number is the culprit? Different ecm program? I am at a loss.
Thanks for any insight
P.S.
What was wrong with the old motor you ask? NOTHING.... LOLOLOL it had 140,000 on it and a tap in the valve train but no problems. I just wanted to get a new motor in so I didn't have any issues later down the road.