JoshCampbell55
Newbie
- Joined
- Oct 16, 2013
- Messages
- 36
- Reaction score
- 7
I have a 99 5.7 that shudders on partial throttle/cruising and feels like its misfiring at idle. This truck has been sitting for 7 years and I'm trying to get it back on the road.
With my scan tool checking misfires per cylinder it seemed to mostly be 2 and 4 but most of the time it shows 0 misfires even when its shuddering so I might need to try another scanner to check that again. I only got a p0300 code once over the last few days so I cleared it and it never came back. Another thing I noticed is if the truck sits for an extended period of time it has a little bit of a harder time starting and then it runs poorly for a minute when it does start.
I replaced the crank sensor a while back because it didn't have a shim and it was hitting, installed new one with a shim. I made sure the distributor was installed correctly and got the CMP to 0.4 degrees with the scan tool at 1000 rpm and did the crank relearn.
I hooked up the fuel pressure gauge and I'm getting around 56 with the key on engine off then when I start it it drops to about 49-50 and doesn't go higher even when I rev it. It holds pressure even after turning the key off.
Are these acceptable fuel pressure numbers with the MFI injector system?
My thoughts are check the fuel pump wiring (maybe chewed a little bit? truck was sitting for a long time)
Or possibly a worn distributor gear?
Adjusted the valves
Compression test all around 150-160
o2 sensors show 0.1-0.9v
MFI Injectors
New Cap, Rotor, Wires, Plugs
new crank sensor
checked all grounds
thank you
With my scan tool checking misfires per cylinder it seemed to mostly be 2 and 4 but most of the time it shows 0 misfires even when its shuddering so I might need to try another scanner to check that again. I only got a p0300 code once over the last few days so I cleared it and it never came back. Another thing I noticed is if the truck sits for an extended period of time it has a little bit of a harder time starting and then it runs poorly for a minute when it does start.
I replaced the crank sensor a while back because it didn't have a shim and it was hitting, installed new one with a shim. I made sure the distributor was installed correctly and got the CMP to 0.4 degrees with the scan tool at 1000 rpm and did the crank relearn.
I hooked up the fuel pressure gauge and I'm getting around 56 with the key on engine off then when I start it it drops to about 49-50 and doesn't go higher even when I rev it. It holds pressure even after turning the key off.
Are these acceptable fuel pressure numbers with the MFI injector system?
My thoughts are check the fuel pump wiring (maybe chewed a little bit? truck was sitting for a long time)
Or possibly a worn distributor gear?
Adjusted the valves
Compression test all around 150-160
o2 sensors show 0.1-0.9v
MFI Injectors
New Cap, Rotor, Wires, Plugs
new crank sensor
checked all grounds
thank you