engine stumble/miss

[danman6677]

OK, Ive replaced the plugs,cap, rotor, rebuilt the fuel pressure regulator and the fuel filter replaced finally injectors rebuilt, the engine was rebuilt in 09 but is clean burning. Im trying to figure out if its fuel or ignition related before throwing more money at it. Ive tried changing the sensors from my 94 but no difference.

 

[JScott23]

Could be a bad plug wire.. have you replaced those? Getting spark to all cylinders?

 

[JScott23]

i'd say plug a OBDII reader in it and see what it tells you one of our work vans keeps misfiring cylinder 3 for some reason, runs like crap now wont even run

 

[danman6677]

The trucks wires were next on my list. I slowly pushed the throttle open and can feel the miss through the rpms. By the way the truck is a 1992 c1500 350 engine.

 

[JScott23]

Okay so you can't plug in a OBDII. I've never had any luck with the OBDI stuff. Your suppose to be able to use a paperclip and count the flashes. I never had any luck tho

 

[OlSmokie]

error codes

The trucks wires were next on my list. I slowly pushed the throttle open and can feel the miss through the rpms. By the way the truck is a 1992 c1500 350 engine.

I use the paper clip method on my '90 and it works great. At least you will see if something has triggered a code. Just cross the two terminals, (I have a short piece of copper wire that I flattened the ends on), turn the key on without starting it and read the flashes. Codes ca be found online here,http://www.gmtuners.com/OBD1_DTC.htm or just google it.

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[danman6677]

It has no codes, and i just replaced the coil and wires...nothing changed.
I checked all the sensors, cleaned the egr and the IAC. And sprayed carb cleaner around the throttlebody but no vacuum leaks.
The only thing left would be the timing and a proper fuel pressure test.

 

[danman6677]

I went for a 2 hour trip and when i was at at tim hortons and stopped to make my order it stalled out it still runs rough too. I checked my TPS and the voltage is good.
Would the CTS do this it doesnt have any black ness in the tailpipe?

 

[danman6677]

I swapped the CTS and the IAC from my smooth running 94 and it started fine but it will stall only in gear after 30 seconds or so. I noticed it will lurch when it is put in drive.