[waltham476]

Im looking for a little help here. Ive been fixing up an old 1993 pathfinder could use some advice. Ive got a hesitation when I take off sometimes causing a little sputtering. I can accelerate through it and the truck runs and Idles fine. Ive replaced the plugs, wires, distributor and rotar. My next move may be the tps. Whats got me puzzled is when the weather is cold hesitaion is missing or slight and gets more noticeable when its warm. My temperature guage has always been completely to the left on cold. It works becuse it goes up when I climp a hill and drops back to the peg on the way down. I have heat but not as warm as It probably should be. I can drive for an hour and put my hand on the engine and its warm but not hot. I assume my thermostat is stuck wide open. Can an open thermostat cause my hesitation by not letting the engine heat up completely? Id check it but its such a PITA to get at. Any thoughts would be greatly appreciated.

 

[88pathoffroad]

Temp problems can definitely cause issues. The engine temp sensor tells the ECU how much fuel it should have according to the temp. If the temp stays too low it can cause driveability problems. Check the thermostat and the temp switch if possible.

 

[waltham476]

I noticed today that it hesitated right out of the driveway. Its was warmer today which is when its really noticeable. I was told that if I turned the wheel all the way to the lock while it was in park a drop in rpm probably indicates TPS problems. It did exactly that. I got my hands on a tps from a wreck ill try tomorrow. Hopefully ill be dealing with temperatrure issues only after that. Why the hell would they put a thermostat behind there? I might put that off for a little while.

 

[waltham476]

If I remove a little coolant to get the temperature up a little until I get to the thermostat am I going to regret it?

 

[88pathoffroad]

If it overheats you will!

 

[waltham476]

What Gives? I changed the thermostat and found the old one to was fine. I put in a 180 degree and found the old one opened at 170 degrees. Maybe that will help a little but I dont exptect much. Why else would this thing stay so cold?

 

[waltham476]

Nevermind perfect temperature this morning! Im still stumped though the old thermostat opened in boiling water althought I didnt check the temp. All I can think of is maybe it was opening at a low temp.

 

[inyourface1650]

thats why I replaced mine. it was a 170 degree nissan stat, put in a new 170 degree stat and it runs way warmer then it did. So obviously the old one was shot.

 

[waltham476]

Getting things up to temperature made the engine light come on. Checked the code on the ECU and got 35 (three green, five red) Exhaust Gas Temperature Sensor. Could this be whats giving me hesitaion problems that go away in the cold and get worse in the summer?

 

[waltham476]

It appears my egr sensor is right on top of my egr valve and splits off into 2 wire harnesses which is not what im finding in the service manual. Im thinking that the engine never getting up to operating temperature for so long has got the egr system very dirty. Would a bad valve or some blockage cause this code 35?