B4000 rough idle, misfire?

[dj_wehr@comcast.net]

I have a 1994 B4000 4.0L V6, 4wd automatic transmission w/ 82000 miles. I get a rough idle sometimes on cold start and sometimes on warm starts. it seems to lope like it is missing and I have a distinct smell of fuel. I believe it is running rich. then after driving a while it will smooth out and run just fine. I have replaced the plugs and wires, and the O2 sensor. i cleaned the MAF, but still have no change. On occasion when starting it sounds as if running on 2-3 cylinders then die. if i pump the gas it would start right up.

Can someone please help?

[dj_wehr@comcast.net]

ok, cleaned the IAC with little to no change. unplugged the MAF and it studders for a second then goes back to the same idle as if it were plugged in. mind you this is an intermittent problem. sometimes it starts fine and runs fine, sometimes it starts rough and smooths out, and then sometimes it starts fine then goes rough for a little bit prior to smoothing out again. has me baffled.

[anton1117@hotmail.com]

I'm far from an expert here, but check the coil pack. I have a 2001 B3000, and mine went bad. I lost half of the engine's power and acceleration. Mine threw up a 'Check Engine' light. I also tried replacing sensor, wires, etc., and it turned out to be the coil pack. Hope this helps.

[dj_wehr@comcast.net]

anton,
i will check into the coil. can anyone tell me if there is a way to test the coil with multimeter? instructions please,.

[dj_wehr@comcast.net]

ok, pulled codes and counted the flashing lights got:
15,73,32. Guess this could be 157 & 332. the 157 is probably because i unplugged the MAF, so still points to the EGR or EGR pressure sensor?
i assume the problem lies within the EGR Valve. Can someone please confirm?

[dj_wehr@comcast.net]

update:

Went to inspect the dpfe and noticed the vaccum hose for the intake side was off. Upon further inspection the exhaust side hose was dry and cracked. replaced both and removed the - battery cable to erase the codes. will keep you posted if CEL returns and the associated codes.

[dj_wehr@comcast.net]

update:

drove all weekend with no CEL, YEAH!!! , but got some bucking at 50+ MPH, that eventually smoothed out. Any suggestions????

[dj_wehr@comcast.net]

update: need help all you experts

cold start the engine idles low and has no power until i drive for some miles. then it leans out and runs fine. also the temp gauge doesn't ever get past the 1/4 line. could the temp sensor be faulty or sticking causing the computer to believe it is warmed up already? is there a way to test that sensor? hate to throw money at parts that are not faulty. Keep in mind that the CEL has not come on.

thanks

[Tyranitar]

You symptoms sound a like either vacuum leak that closes after the parts expand from warming up, or an injector that is leaking down. You may need to take it to someone that has a smoke machine to check for the really hard to find leaks.

[dj_wehr@comcast.net]

ok, thought i had the rough idle fixed. i replaced the IAC and that seemed to fix the problem. 1 month later I have the same problem. my temp gauge is very erratic. shows cold when it is obviously warm or hot. would a faulty thermostat cause engine to run rough? I am not getting any CEL and no code are to be found. I pulled plugs and all look good with good spark.

any help would be nice.