Jump to content

Due to a hardware failure on the hosts systems, all posts and messages created between May 26th and Jan 13th have been lost. Additionally, if you joined the NPORA Forums community during that time, you'll need to re-register. -NPORA Mod Team *Updated: 05/19/2022 12:15AM PST

95 pathfinder engine stumbles/ stalls and hard starting


FindMe
 Share

Recommended Posts

Recently took on a 95 pathfinder 4x4 automatic. 223,000 miles Ran good at first then suddenly would start to spit and spudder then start running good again during the same drive time. Has been doing this last few time I drove it. Seems to run better on highway . When in city seemed to have alot of hesitation when accelleration. Now I am having hard time starting and running correctly. Once I get started I have to feather the peddle to keep it running. If i keep peddle steady it will run for a few second then die. like someone turned the key off. I inspected all vacuum lines and hoses and did discover a tiny hose off on the side of air breather tube between Maf sensor and intake. I repaired broken hose but made no difference. Ran ECU check came back code 55. I have no CEL . I did notice the screws that mount the MAF sensor were partially stripped out like someone has been in there before. the plug clip/lock is broken off and the black protective coating for the MAF wire connector is peeled back and two of the wires looked like they have been previously piggy back spliced onto at some point in time and splice removed since. I have literally have driven this vehicle less than 75 miles total. Just brainstorming here... was thinking about going to junk yard and getting a maf sensor and pigtail connector ,but until I make it to junkyard are there any other ideas? I have also Replaced fuel filter

 

Link to comment
Share on other sites

Does it run fine cold/warming up and then it does this behavior when hot? Is the behavior RPM, speed or gear related?

Has it ever done this idling? If so try wiggling censor connectors to see if the stumbling stops/changes.

 

I would have thought that it is starving for gas, but you replaced the filter. Fuel pressure could be an issue but that is not a common issue.

Have you downloaded a copy of the Factory Service Manual yet? (pinned in the Garage section) You can look up the resistance of various engine control items.

Have you checked for vacuum leaks?

 

B

Link to comment
Share on other sites

The MAF connector is sometimes a problem, particularly its ground. So +1 on repairing its hacked up wiring. Some people run the ground wire right to the body and say it helps. The splices sound to me like the PO tried to hook one of those stupid "fuel saver" resistor kits to it, and in the process knackered the connector and exposed the wires to corrosion. You might pull the sensor off and take a look at it, too, make sure it hasn't had anything harebrained done to it.

Link to comment
Share on other sites

Does it run fine cold/warming up and then it does this behavior when hot? Is the behavior RPM, speed or gear related?

Has it ever done this idling? If so try wiggling censor connectors to see if the stumbling stops/changes.

 

I would have thought that it is starving for gas, but you replaced the filter. Fuel pressure could be an issue but that is not a common issue.

Have you downloaded a copy of the Factory Service Manual yet? (pinned in the Garage section) You can look up the resistance of various engine control items.

Have you checked for vacuum leaks?

 

B

 

it does this cold or warming up or at running temp. no rhyme or reason. I have tried wiggling wires. I havent checked for vacuum leaks yet. Kind of hard to keep it running long enough to check for vac leaks.. It has almost gotten to the point that sometimes itll start and sometimes it wont. at one point unplugged the MAF and truck started right up but wouldnt rev over 3200 rpms but couldnt duplicated it again. I dont know if that was a coincidence

 

 

I have take the MAF sensor off.looks like two bulb filaments. Didnt look corroded or anything so I sprayed with wd40 and put back on. Made no difference. Last week when it was running good i pulled off each spark plug wire seperately while running to see if each cylinder was firing . they all were firing.

 

Which of the three wires on the MAF is the ground? guessing its the black one. I probably wont make it to junk yard till next week

 

 

Link to comment
Share on other sites

My situation was that hood motion would affect how my pathy ran. The way the connector on top of the MAF was built, there was a break and intermittent connection due to the wires actually touching the hood when closed. I would hit a bump or something or there was some twisting/flexing that caused slight hood movement which would wiggle the MAF wire and it would run like crap. I rebuilt the connector so the wires come out horizontal rather than vertical and no more issue with it. Tell tale sign was that, with the hood open and engine running, I would grab the MAF wire and give some wiggle or slight tug and it would affect the running.

Link to comment
Share on other sites

Don't use WD40 on a MAF. There are special cleaners that won't leave a residue. I used denatured alcohol without issue. The MAF works by heating up those little wires and judging how much the air passing cools them, so if they get a burned-on coating of oil from the WD40, the sensor won't work as well.

 

And yeah, I assume the black wire's ground. If in doubt you can test it pretty easy with a voltmeter. Shouldn't be voltage between it and ground (negative battery terminal or a clean spot on the body).

Edited by Slartibartfast
Link to comment
Share on other sites

Don't use WD40 on a MAF. There are special cleaners that won't leave a residue. I used denatured alcohol without issue. The MAF works by heating up those little wires and judging how much the air passing cools them, so if they get a burned-on coating of oil from the WD40, the sensor won't work as well.

 

And yeah, I assume the black wire's ground. If in doubt you can test it pretty easy with a voltmeter. Shouldn't be voltage between it and ground (negative battery terminal or a clean spot on the body).

 

Still havent made it to junk yard. So heres what been happening...... Pathy got to the point where it would not start and run at all. I said what the heck and changed the fuel filter again. It started right up and idled for about 2 minutes b4 it died and would not restart. I again removed MAF sensor and spraying it with brake cleaner and reinstalled it without the rigged up air cleaner adapter, this mean sucking air straight from MAF sensor screen. I put tape over 1/3 opening to mimic aircleaner. Pathy started right up and idled for 20 minutes without dying at a little normal than higher rpm. With it still running I lowered the hood and immediatley the rpm decreased but and a non constistent idle. I raised hood back up to inspect no wires where touching hood and no vacuum lines getting pinched and rpms raised, lowered hood and rpms lowered again. Took for a 2 block drive. Came back home raised hood and put hand over intake and adjusted hand to where I could get it to idle perfect.

 

Im thinking I should just get a stock intake airbreather box or somthing made to actually fit this vehicle and also a muffler instead of straight piped to produce the correct amount of back pressure

Link to comment
Share on other sites

Check fuel pressure with engine off and on. Sounds like fuel pressure regulator flooding engine. Engine ran good after filter change as fuel system was lower pressure then built up and engine started running bad again. Ethanol gas is a killer for our older trucks. My dad's Ford F150 died and wouldn't start up. Pulled air inlet and gas smell was horrible. Checked fuel pressure and it pegged my gauge at 80psi.

Edited by 1987caddy
Link to comment
Share on other sites

  • 2 weeks later...

This is very wierd. After running the pathfinder with the the intake half taped over it was running great.. ran it down the highway about 5 miles.. turned around, engine started stumbling a little, cleared up, got back home removed the tape and ran and idled near perfect. This lasted a few days with just idling in the drive and driving around neighborhood only. Last night I pulled it up onto my pit to bleed the brakes AGAIN (see other thread). finished bleed, started up and backed off of my pit and the engine started stumbling and died. and would not start, like it was out of gas. I fiddled with it and was able to get it to start back up and stay running a little bit if I sprayed a little starting fluid and taped up intake and feathered the throttle. Its like im back to square one again. if I tape off part of intake again(about 2/3 closed) I can get to run a little bit but will immediatley die if I remove all the tape It seems like an air fuel mixture problem.

 

I have been to 5 JY's to find another MAF sensor and harness and stock air breather assembly and have had no luck. When it was running good I unpluged MAF and pathfinder immediatley died

Link to comment
Share on other sites

Check fuel pressure with engine off and on. Sounds like fuel pressure regulator flooding engine. Engine ran good after filter change as fuel system was lower pressure then built up and engine started running bad again. Ethanol gas is a killer for our older trucks. My dad's Ford F150 died and wouldn't start up. Pulled air inlet and gas smell was horrible. Checked fuel pressure and it pegged my gauge at 80psi.

 

I dont see a place to screw fuel pressure gauge. Can I just put a T in right after fuel filter? What should my reading be with key on engine off? key one engine running? where is the pressure regulator located?. Going this morning to buy a fuel pump gauge.

Link to comment
Share on other sites

I had similar issues. Check the Idle air control valve. There is a controller for the valve. The IAC valve is located under the intake on the drivers side. The controller for it is located next to the EGR valve. The service manual has the checks.

 

Another thing to look at is the cam sensor. It's in the distributor.

 

Add a ground to the MAF. Make sure you get the ground wire. If not things will melt.

Link to comment
Share on other sites

got a fuel pressure guage. No pressure. Pulled access cover to pump and one wire brunt off pump it was the white/purple wire .

There are 5 wires at the fuel pump the colors are black, yellow, blue/red stripe, yellow/blue or green stripe, white/purple stripe.

 

I unplugged the harness connector under the vehcle and noticed yellow/purple wire, yellow/green wire, white/blue wire and two black wires.

With key on im getting 7 volts and 8 volts from two yellow wires with stripes. Shouldnt i be getting 12 volts?

 

Why are there 5 wires running to my pump? which wires are for the gauge and which wires power the pump. I found a few diagrams but only show 2 different color wires going to pump, not 5 wires

Link to comment
Share on other sites

OK I think I have FINALLY fixed the problem. It was indeed a burnt connection on the fuel pump.. I have repaired connection and she runs goooood now... 42psi fuel pressure. Is that ok?

Thanks to everyone

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

Welcome to NPORA Forums

 

Please register to gain full access to the forum.

Make sure you read the Forum Guidelines and don't forget to post a new intro in the New People Start Here! section, to say hi too everyone.

 

-NPORA

×
×
  • Create New...