Possible Transmission Issues??

[brlarl]

OK guys, I pulled the lock up plug off the tranny drove it and it did not change anything.  Now I honestly do not think it is the tranny.  I noticed the idle is rather low.  Even with the A/C on it idles low, if I turn the A/C off the idle does not change.  I unplugged the IAC and no change either.  Since there is no idle speed control on the TBI, what controls the idle when the A/c is on?  I still have the surging when I drive, but if I romp the throttle the truck will pick up and move but surges slightly.  The truck has a new fuel pump.  I rebuilt the the TBI about 5-6 month ago and delivers fuel great.  I did a full tune up about 2-3 months ago.  My compressor is acting up, can this cause anything?  I have not noticed by MPGs drop yet.  Any Ideas what may be causing this low idle?

[VileZambonie]

Since there is no idle speed control on the TBI, what controls the idle when the A/c is on?

 

The idle air control motor

Check and make sure ALL of your ignition components are in good shape. If you haven't done a tune up recently then do one. Check for vacuum leaks at the base of the TBI unit. Then check the TPS.

[brlarl]

I have done a tuneup about 2-3mnth ago and I have recently rebuilt my TBI.  Last night I unplugged the IAC and drove the truck.  I can't say that I noticed any difference when I drove it. If either the TPS and the IAC is bad why wouldn't it trigger the Check Engine Light?  I also noticed last night that my a/c compressor clutch is starting to stick.  When in idle and the a/c is on the clutch is spinning then it slows down to a near crawl (as if it is skipping) then spins fast again.  Could this cause the surging that I feel when I drive? Sorry for all the questions, I'm just tryin to figure out why it went from running fine one day to acting up the next.  Thanks Again

[VileZambonie]

Turn the defrost off. The IAC is for IDLE only so it won't make a difference. Even though you did a tune up you still need to check the components. Unplug the TPS and drive it.

[brlarl]

Cool, I'll try that.  Do the sensors have to be completely bad before the "Check Engine" light comes on?  Thanks V

[brlarl]

OK so I pulled the TPS plug off and drove it during lunch today.  The truck drives better and picks up better but the surging is still there not as bad but still there?  I still need to check the componets in the distributor but the cap rotor and wires are all good.  Had time during lunch to check those. Any other suggestions?  Thanks 

[VileZambonie]

Did you spray carb clean at the base of the tbi? The check engine light doesn't come on because a sensor is bad.

[brlarl]

No I didn't spray the base but to make sure the truck runs good for years to come I went ahead and changed the TPS and the IAC to new units.  The truck runs A LOT better but I can still feel the surging just not as much.  I did find the back screw on the distributor cap loose and the contacts with some build up.  I tightened the cap and cleaned the contacts.  While there at the distributor I checked everything and all was good.  Any more suggestions?  Does any one know if I can find a new Engine harness?  I would like to change the whole computer harness for the engine.  I did find some brittle wires on the current harness and fixed them but would like to change it to a new one.  Thanks Guys.

[VileZambonie]

You have suggestions you haven't tried and are now parts changing. Try doing everything suggested first.

[brlarl]

OK so I sprayed the base of the TBI and it did not make a difference.  After I sprayed it, I re-torqued the TBI and sprayed again just to make sure......still no change.  Should I focus on the fuel system?  Any other suggestions V?  Thanks

[brlarl]

Any othe suggestions?   Anyone?  Thx

[TexasRed]

Did you check your plugs? Is the EGR functioning properly? An EGR valve that flows at idle will cause your idle to be low.

[brlarl]

Yeah the plugs, the EGR Valve and the EGR solenoid were checked all are OK.  Actually my idle is OK since I changed the IAC and the TPS but again I still have that darn surging.  Could the fuel pump or fuel filter cause the surging?  Thx

[TexasRed]

Yuppers, could be. I woulda thunk it would have tripped a lean code. Might try changing the fuel filter if it hasn't been changed in awhile just as a good measure anyhow.

[brlarl]

I need help from anyone that may know why my truck is surging.  Can the transmission cause the surging?  I did what Vile said to do and all was fine.  I changed the TSP and the IAC.  I just changed the fuel filter.  I seems everything that I change seems to make the surging less and less.  I have no lights on and the temp is at 195 -205.  The truck does move when the gas is stomped on and there is no hesitation but I still slightly feel the surging.  Any and all help is appreciated.  I need to fix this thing right since it is my daily driver and my only vehicle to get around.  Thanks Guys