Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
01-27-2024, 10:13 PM | #1 |
Registered User
Join Date: Dec 2018
Location: yamhill OR
Posts: 857
|
1998 c1500 4.3 misfire troubles
Hello everyone I have been having trouble again with my 98 c1500 misfiring/running poorly and I'm a bit stumped.
The truck is a 1998 c1500 4.3 v6 5 speed manual 2wd. with 163K on the od So my problem is: Engine Idles a little rough and has what seems like a misfire. Misfiring is worse or more noticeable at what I would call lite load higher rpm conditions. Like 1800 2k-2500 rang while shifting through the gears under lite load conditions and also driving at cruising speeds. The condition is worse in damp wet weather. The condition is like a time I had a bad dis. cap. I have tried Three (3) different dis. caps, one that I had been using, one almost new and one brand new cap. rotor button looks good. Plug wires are not very old and test good with a ohm meter Swapped around spark plugs one cylinder at a time with a good but used spark plug. Brand new Ignition coil (original went bad June of last year) Pretty new ICM (Replaced a year or so ago) I have tried a different ignition coil and Icm from anther truck. TPS sensor tests good. I only had trouble codes for EVAP I drove the truck a for a MONTH like this and had NO MISFIRE CODES I checked several times and then gave up and did not check for a couple months and drove the truck like it is (mostly just to work and back) (12 miles to and 12 miles back 5 days a week) I Recently checked again and I had a code for a misfire on cylinder no.4 I changed out cylinder no. 4 wire just because. I thought at first it may have ran better but was wrong. In my opinion it seems like multiple cylinders misfiring but I can not be 100% sure. Fuel pressure is close to 60psi ignition on engine not running. With engine running its just above 50psi. If my memory is correct the pressure is good? Other then doing a compression check I'm not really sure what next to check so I'm hoping some of you out there have suggestions!
__________________
1965 chevy c20 292 4speed http://67-72chevytrucks.com/vboard/s...d.php?t=777601 1976 chevy c10 250 4speed http://www.67-72chevytrucks.com/vboa...d.php?t=787037 1978 chevy c20 350 4speed 1998 chevy c1500 4.3L 5speed 2002 Chevy s10 4.3L auto 4x4 Plus a Mercury & some Fords... To many projects! |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|