My 95 2500 (K series, 4WD 350) is having problems that I think may be injectors and if it is I'm going to buy the holley TBI unit but I want to make sure before I drop the money on it. The truck is all stock other than a K&N and full exhaust and has just over 120k on her.

First let me state that I did the fuel pump and filter in July.
Now the problem is that it stumbles when starting from a stop, once I get going I can get on it all I want and there are no problems but starting out from a stop if I go anything above 10% throttle the truck stumbles so bad that it dies. I am so skeptical because I have already tried swapping injectors with some I had laying around and it didn't help at all, if anything it hurt. I cleaned the original injectors as well as I could (just by taking them out and cleaning the screen) and put them back in and that seemed to help a little, after that I sea foamed the motor and didn't really notice much of a difference but I only drove it around the block (did that today). The PCM is throwing a lean code every now and then but it appears to be random and has done that since I owned it, when I hook up my snap-on scanner and watch the data feed I don't notice anything out of the ordinary. It does take a few seconds of cranking to get it to start but it has done that since I got it as well. Thanks in advance.

 

Fuel pressure is critical on those things. A stock TBI likes around 13psi. Where's yours?

-Chris

 

I never bothered to test that, I figured that I didnt need to cause it was a new pump, I guess I'm just to trusting in new parts. I keep the truck at work so I'll test that tomorrow. Thanks

 

what is the status

 

Before going all-out replacing stuff....sounds like a tip-in problem. On TBI engines there is no accelerator pump, so the TPS makes up for it. As soon as the throttle moves even a little, the computer sends a big 'shot' of fuel through the injectors. I'd wager your Throttle position Sensor is either out of adjustment or needs replacing. If the sensor is off even a little, you'll get a very bad lean stumble.

 

You could try cleaning the TPS and see if helps at all, after cleaning the one on my 93 and performing the "ultimate TBI mods" I noticed ALOT better throttle response.

The great thing about TBI systems is they are so damned reliable and not very complex....there isnt alot that could be wrong...EGR, Fuel, TPS...

 

stupid question BUT, have you looked at your cap and rotor and plugs? A weak ignition system cant really combust a healthy shot of fuel. If you have a weak ignition/charging system you might not be getting a very good burn at idle.

 

this should help you out a bit more,plenty to read...
http://www.thirdgen.org/techboard/tbi/

 

This is an old tread