Gmc Jimmy 95 misfires and bogs down in mid/high rpm

[detorra]

i just got my jimmy running again for the first time in a while, replaced all the sensors and all the fuel injection components - only thing i havent replaced is ignition control module and coil, but coil tested fine at parts store - i've been driving it for about a week after getting it back on the road and it started missing a little over 2500 rpm's - 3 days later and now it's missing pretty bad to the point of no fire at over 2500 rpm if im in any gear - now if im crusing at 50 or 60 or so at low rpms it'll drive fine no miss, even with gas hard on enough to make it accell without shifting - doesnt miss a lick at idle either.

now my question is, could this be the ignition control module?

[detorra]

Originally Posted by detorra

i just got my jimmy running again for the first time in a while, replaced all the sensors and all the fuel injection components - only thing i havent replaced is ignition control module and coil, but coil tested fine at parts store - i've been driving it for about a week after getting it back on the road and it started missing a little over 2500 rpm's - 3 days later and now it's missing pretty bad to the point of no fire at over 2500 rpm if im in any gear - now if im crusing at 50 or 60 or so at low rpms it'll drive fine no miss, even with gas hard on enough to make it accell without shifting - doesnt miss a lick at idle either.

now my question is, could this be the ignition control module?

noticed the distributor was majorly loose, i sinched it down and it still did same, removed it and the gear was wore down kinda on the bottom with a little play in the shaft. got a new distro and it still does the exact same thing. im kinda worried that i did some damage to the cam gear, is this possible after only driving around 70 to 100 miles with a loose distributor?

[old_master]

It's rather doubtful that any damage was done to the camshaft. The distributor gear is a softer metal making it "sacrificial", (cheaper and easier to repair any damage). Have you checked/replaced the fuel filter and checked fuel pressure and leakdown?

[Griztek]

I second the fuel filter. 4.3 engines are very temperamental when it comes to the fuel filter clogging. It happens fast too. I've had trucks run fine and within 5 miles it can barely idle, all because the filter was clogged.

Put in a new filter and I bet your problems will go away.

[detorra]

Originally Posted by old_master

It's rather doubtful that any damage was done to the camshaft. The distributor gear is a softer metal making it "sacrificial", (cheaper and easier to repair any damage). Have you checked/replaced the fuel filter and checked fuel pressure and leakdown?

no i havent had it checked, but it is hard to start sometimes - but when it misses the rpm's jump alot and it kinda smells rich, even with bad fuel presure will it run rich when missing?

i've been nickle and dimed to death now i hope it fixes the problem

it throws a camshaft range/perf code, and 2 other codes for the crank and cam sensor, i just replaced those also if that helps because we had a no start situation (turned out the timing chain had slop in it)

[old_master]

Best to check fuel pressure and leakdown. If something in the plenum is leaking fuel, it will cause fuel pressure to be low. The exhaust will also smell rich and possibly have a raw fuel odor coming from the engine compartment.
Key on, engine off, fuel pump running: 60psi to 66psi. Pressure must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

It's possible the distributor was not installed correctly and needs to be aligned.

http://files.automotiveforums.com/ga...hp?photo=51302


Post the DTC's in the order they appear on the scan tool.

[detorra]

Originally Posted by old_master

Best to check fuel pressure and leakdown. If something in the plenum is leaking fuel, it will cause fuel pressure to be low. The exhaust will also smell rich and possibly have a raw fuel odor coming from the engine compartment.
Key on, engine off, fuel pump running: 60psi to 66psi. Pressure must remain above 55psi for 3 to 5 minutes after the fuel pump shuts off.

It's possible the distributor was not installed correctly and needs to be aligned.

http://files.automotiveforums.com/ga...hp?photo=51302


Post the DTC's in the order they appear on the scan tool.

i figured out the wire to the coil from cap was bad, replaced it, cleared up a good bit of the missfire, drove a little better- but was still hard to start. i got to the point of not turning it off at gaspumps etc and just drove it till i was staying somewhere for a bit, as i was pumping gas in it it started sputtering worse and stalled, would not start after it stalled and i can hear the fuel pump turning on, the truck sat for about 2 years with some gas in it so my guess is the bad gas messed up the filter and has clogged it up?, i dont have access to a scan tool at the moment but i will try changing the cap and rotor and fuel filter - hopefully then it will start up, you guys aggree?