bobco

I've been having issues with my 88 pathfinder with the v6 engine and TBI. trying understand the fuel system. connected up a fuel pressure gauge up to the fuel line feeding the TB( after the fuel filter), when I turn on the ignition key my fuel pressure builds to 35psi hold for 5 seconds and then falls off, for that 5 seconds I hear the fuel pump running and when it stops the fuel pressure bleeds off quickly. this cannot be right? I would think the pressure needs to build and hold at that 35-37psi. I'm thinking fuel pressure regulator and then fuel pump for replacement?? I'm not a mechanic but don't have a bunch of money to dump into this beast, so I'm trying to work through this problem. thanks for any help Bob.

what the ohms on the 88 injectors?? dam thing is running great now but cannot be trusted, I hate that in a vechicle!!!

the maf is on the right side of the tb, black little box held on with 3 screws, search on this site someone has a procedure on how to clean it with PICTURES

I spoke to soon, darn it , running like crap again. got to believe the injectors are questionable at this point...how do I test them?

could be the mass air flow meter on the side of the throttle body. did the mech clean this??

update, truck is running like a million bucks, pulled the egr out and cleaned upthe passage, it was not to bad. throttle body cleaner on all of the passages on the TB and especailly the one on the bottom that looks like it feeds back to the maf. put all back together and turns out is just need a good cleaning, no parts required. feel better about getting the heater grid out of there that was falling apart also. I believe that one passage that was totally carboned up was the problem. thanks evrybody for the help.

thanks, I think I know where to find that lucas stuff now. a fsm for a 88 would be worth GOLD, well maybe

a little update. I pulled the throttle body off last nite. the mixture heater was fried so I busted out the grid and cleaned it up, will not be hooking power back to it. noticed a passage that is open to the intake was all clogged up with carbon depsoit , this passage was on the throttle body and under the maf, don't know its purpose but it is going to get a good flush with throttle body cleaner tonite. injector tips look clean, but the injectors could still be the issue. going to pull the EGR out tonite and clean that up, looks like passage to it has allot of crud in it. I think I will give it all a good cleaning and put back together and see if any improvements.

sounds like it needs to go away

ran diags , no codes on the ecu, where do ya get this lucas cleaner? factory service manual would be SUPER!!!!!

remove it? I plan on pulling throttle body off, can I just forget to put the heater back on? no noticable effect on performance???

have a 1988 v6 pathfinder with 141k miles on it, has had intermittant poor running problem for some time. i took it to the local nissan dealer to be checked, they said bad/dirty injectors, mixture plate heater bad and tps bad. I put in an aftermarket tps (not sure the idle circuit is workin), still runns like crap, ran some techtron concentrate thru with no help, check fuel pressure with gauge and it is ok. Question is how can I test the injectors? are there some inexpensive injectors that are ok for this engine? Is the throttle plate mix heater and issue or just on cold start ups? thanks for any help I want to enjoy driving this thing again!!!