HELP! Check engine light - Loss of power

[bennelson]

Yesterday, I installed a kill switch in the truck.

Today, the CHECK ENGINE LIGHT no longer comes on, but I am having another problem instead!

I have no power when I put the gas pedal down farther than about half-way!

This gives me terrible acceleration, and I can barely make freeway speed. I can slowly accelerate if I am level or slightly downhill.

Uphill, things start slowing down because I can't push the gas pedal down far enough before it starts losing power!

Also, if I rev the engine up real high, when in neutral with the parking brake on, it sort of shutters and snorts.

Is this a "fuel-rich" problem? When I give it gas, it's getting too much gas, and I lose power?

When I installed the kill switch, I cut the wire to the fuel injectors, and added a momentary off relay in-line to it to turn off the engine.

I put a jumper back in so that that wire is connected directly again (no relay) and am still having the same problem.

Please don't tell me that that's a special wire that has very particular resistance that effects the injectors or something like that!!!!!

What could be wrong with the truck?!?!?!

Thanks in advance!

[TestDrive]

Symptoms sound like it could be a dirty MAF (Mass Air Flow sensor).

[3dplane]

Or a clogged catalytic converter but it's a little coincidental with messing with the injectors. Unless somehow it ran rich for a while.
Barna

[bennelson]

I have heard that O2 sensors can get messed up through contamination. One cantaminate can be antifreeze.

I saw that my coolant looked low. Coincidence? or cause?! If cause, how did the coolant get down and mess up my o2 sensor, head gasket leak?

[2000mc]

first guess, i'd lean twards 3dplane and the converter.

with the vehicle in neutral does it seem to rev freely? only take light throttle to rev up, or quite a bit? exhaust sound different than before? good throttle response only at low rpm?

[bennelson]

Originally Posted by 2000mc

first guess, i'd lean twards 3dplane and the converter.

with the vehicle in neutral does it seem to rev freely? only take light throttle to rev up, or quite a bit? exhaust sound different than before? good throttle response only at low rpm?

In Neutral, it revs freely, needing only a light touch. Reving it high makes the engine loud and kinda cough/sputter/chug.

The exhaust does should different than before. More "swooshy".

Throttle response at low RPMs seems good, but not at the more highly depressed end of the throttle.

[Metrosexual]

It sounds like your cat is plugged, catalytic converter that is....
This could cause your check engine light to come on and set a cat efficiency code.
I have never had a communication problem using a Snap-On or Modus Scanner on a '95 S-10 with a 4.3 Vortec and an OBD II style connector. There may be an electrical problem in the wiring between your vehicle computer and the OBD II connector.
I think your going to have to have this problem diagnosed by a qualified tech, as it sounds like there are several things going on.
One thing you can check is all your fuses. There are several ECM (vehicle computer) fuses. I'm not certain if a blown fuse would cause your communication problem, but it wouldn't hurt to check.

[bennelson]

The '95 6 cylinder has OBD2, the 4 cylinder doesn't! Still has the same style connector though!

[3dplane]

A quick test for those simptoms and to find out wheter it is the CAT or not is to disconnect the exhaust somewhere between the motor and the CAT.
Crank it up and nail the throttle to see if the "peppyness" is restored.
If nothing else the neighbours will be very impressed....
You will be able to tell if there is difference in one punch of the throttle in neutral. That's how we do it in the shop if in doubt.
Barna

[2000mc]

bennelson - think i spoted something helpful

Some 1995 GM vehicles have the 16-pin connector but have accessible OBD-I codes. Check the underhood emissions sticker to confirm, and if yours is OBD-I, the codes are accessed by bridging terminals 5 and 6

found on Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical