dkpath96 Posted December 24, 2006 Share Posted December 24, 2006 (edited) Here's the story so far: 1) It all started with tiny little 'hiccups' from the engine that would cause a hesitation while driving, causing the vehicle to lurch a little bit. At first I only noticed it when in low RPM and at speeds less than 40 mph. And they were few and far between... 2) Then one day while driving into town I was going 35 in 3rd gear and the hesitation lasted longer - a few seconds - the engine acted as if it wanted to stall... 3) The kicker was a week later when I was going 50 in 4th gear (~2500 rpm) and the pathy just stalled out completely, the engine ran real rough and shut down. I got it off the road and let it sit a minute, then fired it up fine - but it ran real rough, coughed and sputtered and died within 20 seconds. Did this two more times before I decided I can't get it home, and had it towed to the local garage... 4) The mechanic didn't get to it for a week, then said he fired it up, drove it around for 15 minutes, then let it run idle in his parking lot for 3 hours and didn't notice any problems whatsoever. He changed the fuel filter (broke the harness and attached the new one with zip ties... pssd ) and sent me on my way... 5) My cousin and I wanted to test the fuel pressure in and out of the engine, so we pulled the fuel pump fuse (it was fine, as was the relay) and the way the pathy sputtered and stalled during this time was identical to its symptoms when it stalled on the way home before. But we didn't have the right T-fitting to test the pressure, so we really couldn't do anything else. The fuel pump still whines as it should when the key is turned on... 6) I am still driving it short distances and it is still lagging at certain random times. I replaced the plugs, rotor, and dist. cap last year and it has a refurbished MAF sensor less than a year old, and of course a new fuel filter. I think I have it narrowed down to 3 things: a. fuel pump going bad b. fuel pressure regulator going bad c. an electrical short in the wiring to the above parts (please.. not this) But could it be something else, like O2 sensors or possibly the refurbished MAF sensor, or something I've not thought of? :help: p.s. Merry Christmas! Edited December 24, 2006 by dkpath96 Link to comment Share on other sites More sharing options...
88pathoffroad Posted December 24, 2006 Share Posted December 24, 2006 Fuel pumps usually just quit working rather than spottily not providing fuel. If anything, I would suspect wiring issues or the MAF sensor again. Have you run the error codes? Link to comment Share on other sites More sharing options...
dkpath96 Posted December 24, 2006 Author Share Posted December 24, 2006 The check engine light came on only after it stalled, and after pulling the code manually, it gave a code "12" or a code "1212" (one blink, pause, two blinks, pause, repeating). This code wasn't in the Haynes manual but my cousin thought it was a "no codes" code. And it never came back after we cleared it. Link to comment Share on other sites More sharing options...
88blk4x4 Posted December 24, 2006 Share Posted December 24, 2006 (edited) it's probably the ballast resistor in the fuel pump....I have had 2 different cars do the same thing. a 89 thunderbird that mainly stalled from a take off or going uphill and a 87 Crown vic police car that I just changed the fuel pump in a month ago. it would miss out and hesistate and spit and cough, that lasted about a year...Thanksgiving day of this year I was going up one of our many mountains and could barely do 35 flat on the floor...changed the fuel pump the next day and it hasnt miss out yet...I believe it's the fuel pump from the way your describing it Edited December 24, 2006 by 88blk4x4 Link to comment Share on other sites More sharing options...
94extreme Posted December 24, 2006 Share Posted December 24, 2006 fuel pumps do that sometimes sometimes but my guess is O2 or MAF.. when it sputters, depress the shroeder valve on the fuel rail and see if fuel shoots out of it.. if yes, then your pump is most likely ok. i'd go back to the mech and bitch about that filter fix. have him buy you a new bracket. Link to comment Share on other sites More sharing options...
dkpath96 Posted December 24, 2006 Author Share Posted December 24, 2006 depress the shroeder valve on the fuel rail I didn't think the VG33 had a schroeder valve, but if it does, could someone point it out to me? I'm going to a different garage next week to have a fuel pressure test done as per the haynes manual's advice. Wouldn't a faulty oxygen sensor throw a code and light my SES? Link to comment Share on other sites More sharing options...
nissandoms47 Posted December 24, 2006 Share Posted December 24, 2006 yes it would throw a code. If your not close to an autoparts store you can read the codes yourself by taking out the ECU and switching the dial to diagnostics, this will cause your SES light to blink. those blinks are the codes. Link to comment Share on other sites More sharing options...
94extreme Posted December 24, 2006 Share Posted December 24, 2006 it may or may not throw out a code. the valve should be in each rail somewhere near either end. if there is a bunch of gas coming, it's good. Link to comment Share on other sites More sharing options...
88pathoffroad Posted December 25, 2006 Share Posted December 25, 2006 it's probably the ballast resistor in the fuel pump....I have had 2 different cars do the same thing. a 89 thunderbird that mainly stalled from a take off or going uphill and a 87 Crown vic police car that I just changed the fuel pump in a month ago. it would miss out and hesistate and spit and cough, that lasted about a year...Thanksgiving day of this year I was going up one of our many mountains and could barely do 35 flat on the floor...changed the fuel pump the next day and it hasnt miss out yet...I believe it's the fuel pump from the way your describing it No such thing as a ballast resistor on a Pathfinder, sorry. Those are Fords... Link to comment Share on other sites More sharing options...
88blk4x4 Posted December 25, 2006 Share Posted December 25, 2006 No such thing as a ballast resistor on a Pathfinder, sorry. Those are Fords... oh ok...I know all 3 of my fords have had fuel pump problems and 2 was doing the same thing...the parts store said it was a bad ballast resistor...have no idea what it is, but changed the pump and havent had any problems..... Link to comment Share on other sites More sharing options...
dkpath96 Posted December 26, 2006 Author Share Posted December 26, 2006 (edited) Just out of curiosity, does anyone know what the '12' or '1212' code from the ECU means? I've been browsing the haynes manual and am planning on testing the MAF and the throttle position sensor. Problems with these are to set off a trouble code but the last MAF went bad and didn't set off a code... Edited December 26, 2006 by dkpath96 Link to comment Share on other sites More sharing options...
94extreme Posted December 26, 2006 Share Posted December 26, 2006 ^^^ P1212 - ABS/TCS Communication Line Link to comment Share on other sites More sharing options...
dkpath96 Posted December 28, 2006 Author Share Posted December 28, 2006 (edited) The fuel pressure test came up fine, so the fuel pump is working. The MAF sensor harness was damaged when it was replaced last spring so I am now looking for the wire leads and harness to the sensor. The local junkyards don't have any R50s - anyone know where to find something like this? Edited December 28, 2006 by dkpath96 Link to comment Share on other sites More sharing options...
dkpath96 Posted January 1, 2007 Author Share Posted January 1, 2007 I am now looking into replacing the MAF and its wiring connector harness, which is loose and being held on with electrical tape... If this is a MAF issue and not just the wiring, do you think I should inspect my existing one and try to clean it with rubbing alcohol or something, in case it is dirty or oily? I do have a K&N filter and it seems as though these problems started after I cleaned and oiled the filter a couple months ago... perhaps I over-oiled it?? Link to comment Share on other sites More sharing options...
NismoSkyZ Posted January 1, 2007 Share Posted January 1, 2007 It is a very common problem that a k&n filter is over-oiled. Without a doubt, I would try and clean the filter instead of replacing it. Why would you waste the money on a new unit when the old unit could just need a cleaning? Link to comment Share on other sites More sharing options...
dkpath96 Posted January 2, 2007 Author Share Posted January 2, 2007 Wow, the maf sensor was dirty. I got it all nice and shiny and it idles so nicely now! Plus I definitely found the culprit of the engine cut-outs - the MAF wire connector! Even the slightest jiggle causes the engine to cut out, so I'm sure that is the problem. I'll let y'all know how things run once I get it replaced. Thanks for all the input! Link to comment Share on other sites More sharing options...
dkpath96 Posted January 12, 2007 Author Share Posted January 12, 2007 Ok, I wired in a new MAF sensor connector and have been driving it to work for a week without having the engine completely cut out and stall on me. However, the hiccups are still there. Once again I've tried to narrow it down and so far have been noticing them within the first 15-20 minutes of driving and when I'm cruising with the foot just barely applying pressure to the pedal, and the RPMs around 1500-2000. When it happens, it feels like the engine wants to stall but then it recovers and seems to drive fine for the remainder of the trip (another 30 min or so). Also I've noticed that the idle RPMs are unsteady until the engine really runs for a while. They bounce from 700 to 1000 to 1200 and such. When I get home and sit in the driveway watching them (45 min drive time), they are settled down to 800 or so and don't vary. I read up on MAF sensors and get the idea on how they work, but is it true that after the engine (or exhaust) reaches a certain warm-up temperature, the oxygen sensors are more 'in command' of the engine? If so this could point to a bad MAF. I also read that MAFs cannot be repaired - only cleaned or replaced. And lo and behold, mine has a nice fat sticker on it saying it was "re-manufactured".... Link to comment Share on other sites More sharing options...
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