mudpie
I'm Awesome
1996 C2500HD, 5.7
I had some fuel delivery issues a few months ago. The end result was a new fuel pump, fuel filter, and updated spider assembly. I've been driving the truck every day since then (two months), including two trips of 300 or so miles, and it's been running fine. My mileage is consistently around 13, plus or minus a little, which seems ok to me for a truck of this size. I've done nothing to it since the fuel issue was resolved.
Now the truck has learned a new trick.
The short version - With plug wires 1 and 3 pulled off, the truck starts and runs, though obviously only on 6 cylinders. If I put the wires on for either 1 or 3, it will just crank, won't start, and the plugs are all fuel fouled.
The long version - The truck was running fine. I had a CEL that was P1345 (Crankshaft Position-Camshaft Position Correlation) that was the result of installing a new distributor/cap/rotor/module, and the timing wasn't exact. I've been meaning to take it in to a shop and have them scan it and set it, but hadn't done it yet. Like I said, the truck was running fine, so if it was off it was only by a little.
Drove the truck this past Saturday, came home, shut it off, and an hour later it wouldn't re-start. Cranked and cranked but wouldn't fire. I could smell gas in the exhaust, so I pulled all the plugs and they were covered in fuel. No noticeable wear, gap was good, and they had a nice light brown color when I checked them a couple months ago. Hard to get a read on the color now since they were fuel soaked, and black from not firing. Cleaned them, put them back, still wouldn't fire. Pulled them again and they were fuel soaked again.
I checked for spark next. Pulled the #1 plug wire and plug, stuck the plug in the wire and had someone crank it. No spark. Pulled the #3 wire, left plug 3 in place, put the #1 plug in the #3 wire, cranked it, got a spark, and the engine started almost immediately.
Put the #3 wire back on, truck won't start. Put the #1 plug back in, and the #1 wire on, truck won't start. Swapped the #1 wire with #2 to check if the wire was bad. It's not. #2 still fires, #1 still doesn't. Checked resistance.... .355 in wire #1, .377 in wire #2 (wire 2 is a little longer.
So now the truck starts right up, and seems to run fine given that it's only firing on 6 cylinders. Plugs 1 and 3 are in, but the wires are off. Down on power, obviously, but otherwise seems ok. I went to Autozone to use their code reader, thinking I'd have a bunch. I only have one...P1345. I thought I'd have a bunch of misfire codes, maybe fuel pressure codes, whatever. I've got nothing.
I'm lost. As I mentioned with my initial fuel problem thread back in December, I'm not a Chevy guy. This is the first GM product I've every owned, so I'm not familiar with whatever common problems these vehicles may have, and as such I have no idea where to begin looking to solve this problem.
Any thoughts or suggestions appreciated.
I had some fuel delivery issues a few months ago. The end result was a new fuel pump, fuel filter, and updated spider assembly. I've been driving the truck every day since then (two months), including two trips of 300 or so miles, and it's been running fine. My mileage is consistently around 13, plus or minus a little, which seems ok to me for a truck of this size. I've done nothing to it since the fuel issue was resolved.
Now the truck has learned a new trick.
The short version - With plug wires 1 and 3 pulled off, the truck starts and runs, though obviously only on 6 cylinders. If I put the wires on for either 1 or 3, it will just crank, won't start, and the plugs are all fuel fouled.
The long version - The truck was running fine. I had a CEL that was P1345 (Crankshaft Position-Camshaft Position Correlation) that was the result of installing a new distributor/cap/rotor/module, and the timing wasn't exact. I've been meaning to take it in to a shop and have them scan it and set it, but hadn't done it yet. Like I said, the truck was running fine, so if it was off it was only by a little.
Drove the truck this past Saturday, came home, shut it off, and an hour later it wouldn't re-start. Cranked and cranked but wouldn't fire. I could smell gas in the exhaust, so I pulled all the plugs and they were covered in fuel. No noticeable wear, gap was good, and they had a nice light brown color when I checked them a couple months ago. Hard to get a read on the color now since they were fuel soaked, and black from not firing. Cleaned them, put them back, still wouldn't fire. Pulled them again and they were fuel soaked again.
I checked for spark next. Pulled the #1 plug wire and plug, stuck the plug in the wire and had someone crank it. No spark. Pulled the #3 wire, left plug 3 in place, put the #1 plug in the #3 wire, cranked it, got a spark, and the engine started almost immediately.
Put the #3 wire back on, truck won't start. Put the #1 plug back in, and the #1 wire on, truck won't start. Swapped the #1 wire with #2 to check if the wire was bad. It's not. #2 still fires, #1 still doesn't. Checked resistance.... .355 in wire #1, .377 in wire #2 (wire 2 is a little longer.
So now the truck starts right up, and seems to run fine given that it's only firing on 6 cylinders. Plugs 1 and 3 are in, but the wires are off. Down on power, obviously, but otherwise seems ok. I went to Autozone to use their code reader, thinking I'd have a bunch. I only have one...P1345. I thought I'd have a bunch of misfire codes, maybe fuel pressure codes, whatever. I've got nothing.
I'm lost. As I mentioned with my initial fuel problem thread back in December, I'm not a Chevy guy. This is the first GM product I've every owned, so I'm not familiar with whatever common problems these vehicles may have, and as such I have no idea where to begin looking to solve this problem.
Any thoughts or suggestions appreciated.
