92 Pathfinder partial throttle hesitation

[jermo47]

Greetings! Been using the forum for a few years now for great information for my 93 pathfinder which is running great. But i am having a problem with my 92 pathfinder project and my searches on the site have not been very successful.

My 92 pathfinder 4x4 manual has a hesitation on partial throttle where it kind of feels like a misfire or delay. Full throttle there is no issue and it idles like a champ.  So far the following has been replaced:

Timing belt / water pump

Distributor
Fuel filter
Fuel injectors (just finished replacing these earlier today)
Spark plugs and plug wires
various vacuum hoses etc.

I am basically stumped. My ECU shows 5-5 (which means running normal or no codes i believe) so the ecu is not sensing anything.

Was thinking about replacing the fuel pump and maybe the o2 sensor? anyone have any thoughts or recommendations?

Thanks to everyone on here. This forum has been a godsend trying to keep these old pathfinders alive!


 

[jermo47]

Just now, jermo47 said:

Greetings! Been using the forum for a few years now for great information for my 93 pathfinder which is running great. But i am having a problem with my 92 pathfinder project and my searches on the site have not been very successful.

My 92 pathfinder 4x4 manual has a hesitation on partial throttle where it kind of feels like a misfire or delay. Full throttle there is no issue and it idles like a champ.  So far the following has been replaced:

Timing belt / water pump

Distributor
Fuel filter
Fuel injectors (just finished replacing these earlier today)
Spark plugs and plug wires
various vacuum hoses etc.

I am basically stumped. My ECU shows 5-5 (which means running normal or no codes i believe) so the ecu is not sensing anything.

Was thinking about replacing the fuel pump and maybe the o2 sensor? anyone have any thoughts or recommendations?

Thanks to everyone on here. This forum has been a godsend trying to keep these old pathfinders alive!


 

Oh I forgot to mention that I also swapped my TPS and MAF sensor back and forth between my good running 93 pathfinder and the 92 so those appear to be functioning properly.

[level9]

The only thing I could think of that would exactly match those conditions (fine at WOT and idle) would be the EGR which operates in the area between WOT and idle.

You can easily rule this out by unplugging the solenoid connector that controls the vacuum which should disable the EGR. It's a little black thing with 3 vacuum lines attached located below the throttle body.

 

For the O2, I also think you can just unplug it and see if the behavior goes away in order to rule that one out. This is located on the pass side fender where a bunch of connectors are attached. Locate the one that has wiring that goes to the back side of the engine/across the transmission.

[Slartibartfast]

Mine did something similar. Kinda fell on its face just off idle, otherwise fine. The plug for the MAF was worn out. Hasn't done that (or the stalling at idle that it also sometimes did, which usually went away for a while when I messed around with the plug) since I replaced the pigtail.

[jermo47]

Okay I'll test the EGR and the O2 sensor by unplugging them. 

 

I'll take a look at the MAF connector as well but I cleaned the connection when I did the testing with the MAF from my good running Pathfinder but not a bad idea to give it a thorough looking at. 

 

Thanks! Will report back after I test. 

[Slartibartfast]

Mine was clean too! I think the pins were just wallered out.