Weird hesitation

[Anvilair]

I have a 1995 Yukon with the 5.7. 166k. New fuel pump, pcv valve, fuel filter, wires, ignition coil, air filter, belts, cap, rotor, exhaust system, exhaust manifolds and gaskets, Vacuum hoses and plugs. Rebuilt trans btw

At exactly 1700 rpm if I let off the throttle or hold it steady at 1700 rpm I get a bog or hesitation. I also at times feel a strange pulsing in that same rpm range. The truck runs smooth otherwise. I cant seem to figure this one out!!!! Any ideas??? Thanks in advance!

Dave

 

[Anvilair]

OK!!! I found the problem!!!! The throttle position sensor was causing the bogging and the EGR valve was causing the pulsing and hesitation.

The truck also used to shift a bit hard from 1st to 2nd and now drives as smooth as a new vehicle.

TPS $21
EGR Valve $40
Driving a super smooth running Yukon...... PRICELESS

 

[tahoeman21]

bog and hesitation

hey wassup? my 99 tahoe is doing the exact same thing that your yukon was doing. I had the SES light come on a couple of times. I took it to my mechanic and scan the tahoe's computer..... the MAF sensor came up and that it was "out of range"..... its annoying but i will get it fix soon. Im glad that you were able to fix the problem. Enjoy your yukon!!! for how long did you have this problem?

 

[Anvilair]

I had it for about 2 months and with the old 5.7 it never tripped a check engine light so I had to chase the problem.

 

[tahoeman21]

hesitation...

How much was it to rebuild the tranny?

 

[Anvilair]

I found a used one in a running yard truck. I paid $200 for it and pulled it myself and then I rebuilt it and installed it myself. Total cost was about $600 including the $200 purchase price. I was quoted a price of $1400 to have a shop rebuild the one I had in the Yukon if I had chose to go that route.

 

[qlc1964]

does these trans have selonoids in them for the different gears shifts?
my 95 yukon has 190.000 miles on her but no trans problem.

and glad you found the problem

 

[Anvilair]

does these trans have selonoids in them for the different gears shifts?
my 95 yukon has 190.000 miles on her but no trans problem.

and glad you found the problem

I also have an 88 GMC 1500 4x4 with the same trans and at 190K I started to get a mild slip. I put Lucas Oil transmission additive in and I have not had a problem for almost 2 years. Sounds like you have a long way to go on yours if you aen't having issues yet. :thumbsup:

 

[tahoeman21]

weird hesitation....

well there are times that when i mash the pedal to the floor, the engine revs but i don't feel any power moving the tahoe..... i assume because of the MAF thats causing this.....


the tranny has 101K miles on it.... i was told that i need to change the transmission filter.... last time, i only had the tranny flushed but didn't replace the filter...

The engine was rebuilt at 95K miles.... had that infamous intake manifold leak, and it was a bad one because the coolant got mixed with the engine oil and got to the bearings!!!! The engine is doing fine.