4.3 lacks pickup

[DetroitMuscle]

I have a 92 T-10 2 dr 4x4, it has a 4.3 Z motor, It runs fine, a vacuum leak in the 4x4 system but thats what a twist lok cable is for. It lacks pickup, Ive done a full tune up, just had a cat back put on not to long ago, it has 147K on it.


Any info on where to look is helpful, ive also cleaned the EGR valve.

Thanks

[ZL1power69]

is your ses light on? if your truck has O2 sensors, how long has it been since they have been replaced? a bad o2 can richen the engine and cause it to stumble. you may need to run a bottle of fuel injector cleaner through the tank if you have not done so in awhile.

[DetroitMuscle]

Originally Posted by ZL1power69

is your ses light on? if your truck has O2 sensors, how long has it been since they have been replaced? a bad o2 can richen the engine and cause it to stuble. you may need to run a bottle of fuel injector cleaner through the tank if you have not done so in awhile.

Ive seafoamed it, no lights but ABS for right frnt sensor, O2 I havnt checked but its not stumbling, It drives fine, until I floor it then it takes forever to respond and when it does its very weak. The tranny is not slipping at all either, Im confused, The motor was rebuilt almost 30k ago.

[BlazerLT]

Reset your timing to base zero.

Unconnect the black and tan wire under the passenger front footwell carpet going to the PCM, you will see a connector you can unattached.

Set the timing to zero.

Reconnect the wire.

Also, what did this full tuneup include?

[DetroitMuscle]

Originally Posted by BlazerLT

Reset your timing to base zero.

Unconnect the black and tan wire under the passenger front footwell carpet going to the PCM, you will see a connector you can unattached.

Set the timing to zero.

Reconnect the wire.

Also, what did this full tuneup include?

Plugs,wires,cap,rotor,all filters, coolant change, all fluid change, wipers, basically a very expensive tune up. Now setting the timing on these pigs is identical to small block chevy timing adjusting , correct?

[BlazerLT]

Remove the timing wire, set to zero, reconnect wire. Remove negative battery cable to clear the computer and start'r'up.

[DetroitMuscle]

Originally Posted by BlazerLT

Remove the timing wire, set to zero, reconnect wire. Remove negative battery cable to clear the computer and start'r'up.

Will do, thanks.

[Cloud Strife]

Plz give an update to this thread once you complete the clearing process. I am interested in the results.

[DetroitMuscle]

Originally Posted by Cloud Strife

Plz give an update to this thread once you complete the clearing process. I am interested in the results.

Im gonna try to do it today but might not happen for a few weekends yet.

[blazes9395]

I agree with LT check the timing, and adjust if needed. If that doesn't work, disconnect the EGR , and plug the line, and take it for a drive, see what that does.

[DetroitMuscle]

Originally Posted by blazes9395

I agree with LT check the timing, and adjust if needed. If that doesn't work, disconnect the EGR , and plug the line, and take it for a drive, see what that does.

I did the EGR thing, it didnt change anything at all. the idle didnt even stumble when I pulled the line.

[mattyspankin]

have you had the fuel pressure checked, you could have a bad pump....?
my 4.3 was lacking pickup as well changed the pump and module and it runs like a top now....not enough pressure means not enough fuel therefore engine wont run like it should

[BlazerLT]

Originally Posted by DetroitMuscle

I did the EGR thing, it didnt change anything at all. the idle didnt even stumble when I pulled the line.

And what about the timing?

[DetroitMuscle]

Originally Posted by BlazerLT

And what about the timing?

I didnt get to it that day, the new weekend isnt here yet. I doubt I can do it this weekend either.



the Fuel pressure is fine, the thing moves when you floor it in first but if you are in 3rd or OD and kickdown to 2nd(passing) it doesnt have the pick up it should, Other then that it runs just fine, a little noisy but i get between 13-19 mpg to each tank. I want to know why nothing changed when the EGR was unplugged.

Ive always ditched the smog systems first but this car needs to keep em due to its daily duty.

[twistedtech]

For starters,if the plug gap is off either way it will affect alot of different things.Wrong plugs,cheap wires or what ever will cause issues as well.The timing can handle more than a 0 base,try it 6,8 maybe even 10.As far as the in tank fuel cleaners,save your money,they only clean the pintle and the pintle alone.A real carbon clean,ie:motovac, will clean all,intake runners,valves etc etc.