Making a list and checking it twice...

[boberoberson]

Hello all and Im here to ask a question or two. Im making a list which so far includes the timing and ignition coil and the emission systems for my 1988 chevy monte carlo 4.3 v6. The car runs rough in gear(drive or reverse) but in park she run's normal till warmed up. Anything you guys can think of for me to specifically check would help, thanks for the thoughts! 😀

 

[pontiacgp]

I would add carb and start off checking the choke

 

[boberoberson]

its tbi :wink:

 

[pontiacgp]

then for my next suggestion I would forget about the carb.....


but the system must have some settings for the start up...

 

[boberoberson]

well the motor was rebuilt not too long ago and doesnt have alot of miles on it nor the trans. they were rebuilt by shops and i reinstalled them to try and learn. it passed inspection miraculously but in gear she's sluggish

 

[clean8485]

Just out of curiousity, have you owned the car for long? The reason why I'm asking, is that these engines weren't the strongest or smoothest engines at the time. GM eventually redesigned the 4.3 in the early '90s to accomodate a balance shaft, to make the engine a bit smoother. I'm not saying that you don't have a problem, just not sure what your expectations of the car are.

 

[Poncho61]

Is that rough running at idle, or at speed, or both? If its real rough at idle or while trying to maintain a speed, but smooths out when you're trying to accelerate, check the EGR system. At idle, I like the above description about those not being the smoothest when new and redesigned to cure that.

If it gets rougher when accelerating, check the timing, coil, wires, plugs, fuel pressure.

 

[boberoberson]

ill post what i find =D thanks for the input! :wink:

 

[boberoberson]

ignition coil primaries =.1 ohm secondaries = 9000 ohms ground was fine. since i now realize i forgot to check and set the dwell(noob) ill do that tommorow. the timing at idle was 12, i reved it some it jumped to 20 and when it went back down was bouncing between 8 and 12. tommorow after work if its not raining ill probally check the dwell and egr. :wink:

 

[boberoberson]

Today checked the egr, at first it was pretty stiff but after a few trys and taking it off i could get the diaphram to move, also putting my finger over the small inlet to see if the diaphram would move and it wouldnt till i let go. i forgot to mention i removed the tan and red wire connector from the distributor to try and appropriately check the timing and it wont start. yesterday i checked it when the wire was connected. :?