Pathfinder wont stay running but starts and idles fine?... HELP

stikky_p · Apr 17th, 2008, 07:09 PM

Hey guys... I have a 1987 pathfinder 4x4 manual tranny.. The vehicle runs rather well just at idle. When you push on the pedal it bogs out and wants to stall.. u think u wanna rev it up to feed more idle but it bogs more.. then dies.. its got the electro injection. with the carb and the 2 injectors in the middle. Im thinking it might be fuel problem. either to lean or rich. ive changed to fuel filters and enough fuel pressure seems to be coming through. could it be a vaccum issue? as soon as you press the pedal to accelerate it dies out.. just wondering what the cause might be?? could it be a head gasket issue? i noticed a small coolant leak but im not sure where its coming from.. no overheating or anything tough.. and i only have to fill the resevoiur a tiny bit every now and then.. so im thinking its not that.. need help.. .

biostockman · Apr 18th, 2008, 10:15 AM

Sounds like a mass air flow sensor problem or it could be the fuel pump. I had the same issue years ago with my 300zx and it was the mass airflow sensor.

stikky_p · Apr 18th, 2008, 06:18 PM

I've tried 2 seperate mass air flow sensors and they worked exactly the same... Some one had mentioned maybe timing? maybe thats my issue? i went and started it today.. started perfectly and idles a little high at 1300 rpm then once it warms up it drops.. when you step on the pedal in chugs out and dies...

**88pathoffroad** · Apr 19th, 2008, 11:53 PM

Could also be the throttle position sensor, have you messed with that at all? Run the ECU error codes and see if anything comes up.

stikky_p · Apr 20th, 2008, 02:00 PM

i havent messed around with that no.. dont know what i'd mess around with a tps.. the vehicle is showing no codes.. well code 55 i do beleive it is.. which is no codes reporting..

stikky_p · Apr 20th, 2008, 10:04 PM

its actually code 44... but still... no codes in the ecu... i couldnt remember the code but i know it reported no problems.. im going to do a couple things so i can count them out.. i think this would be good tests..

fuel pressure test
injector ohm test
checking vacuum lines or leaks spraying carb cleaner listing for idle changes

thats just to start i guess.. if anyone has any head up on the injector test can you let me know.. I dont know exactly what the ohm should be using a multimeter.. or if there is a easier way??

stikky_p · Apr 24th, 2008, 11:46 AM

actually scrap that.. im going to try timing first.. for some reason i think that may be my issue..

stikky_p · Apr 24th, 2008, 07:02 PM

OK OK WOAH!!!!! I think i have a breakthrough.. I went out to mess around with the unit.. charged the battery because i mistakingly left the inside light on.. DOAH... then started it... started great with it boosted.. took the booster off and all was good as normal.. let it warm up and decided to test it and IT WORKED!... there was no more stumble.. however when i drove it around the back alley i noticed it was lacking in power.. and when i reved the engine up it would backfire.. but only when the idle was coming back down.. i would rev it to like 3000rpm and on the way down at about 1500 or so it would backfire and spit a little black smoke out.. not a ton.. barley noticable.. DOES THIS HELP?? i also noticed i was little low on fuel and coolant.. not severly but rather low..