# 96 truck cuts out on hard acceleration



## halbinath (Apr 29, 2010)

so here goes,
I bought a 1996 nissan pickup off a friend unaware that it had this crazy problem. It is a 2wd 5speed. Unless you get on the throttle heavy, or know these trucks well i'd imagine, you couldn't even tell it had issues. 
The problem is when you give it over half throttle, when it hits 3000 rpms, the motor cuts out for 3 seconds of so until the rpms drop back down to 2500 or so, then it pops a few times and comes back to life. If you hold the throttle down less than that, it will rev up fine and run like normal. It will also do it if you hold in the clutch and rev the motor. there is also a severe lack of power in the higher gears. top speed is somewhere around 70. I don't know if this is related or not but the rpm meter jumps all over the place sometimes, even if the truck is on, but not started. It will bounce off the bottoms of the gauge on both sides. The check engine light is not on while the truck is running but if I plug it in i get error code p0171, fuel system too lean. 

things ive done so far
Sprayed and checked all around for vacuum leaks
checked MAF sensor with another MAF, no change
Changed Fuel filter
Checked fuel pressure with and without the regulator, seemed fine 35 or so with reg hooked up and 43 or so without. 
Changed PCV valve
Changed TPS and Adjusted it
Changed Air Filter 
Fixed burnt hose under bpt valve
Changed plugs, new wires
checked cat and muffler, all clear.
Ran several tanks of premium fuel through it with some injector cleaner, no change.

Some things im not sure about, I was going to change the cap and rotor, but as I was in the process of taking it off it looks like someone has either lost or stripped out the normal bolts that hold it on, There is A bolt and nut on the back holding it on. It's tight, but not oem. I'm not sure If this was how it was originally and they just put in a different bolt, or if it was set up totally different. I was starting to think mabye that they had been messing around in there and messed something up, might be why the rpm meter bounces all over, IDK though.
Also, when I turn the truck on, the fuel pressure runs up, but if you dont start it right away, it drops back off to zero, Is this normal? fuel pressure seems fine while running and no issues starting.

Any Help is appreciated, I've been dealing with this for about six weeks now and can't seem to figure it out.


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## schmauster (May 18, 2010)

Sounds like your fuel pump is dying, even though you are getting good pressure at idle, it might not be supplying enough fuel at speed. It should definately hold pressure. It could be a leaky injector too but it isnt hard to start or missing while running.


Drive with the fuel pressure gauge if you can, and if it drops change the fuel filter, then the pump if its still acting up.


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## schmauster (May 18, 2010)

If you cant see your gauge while driving, you can give the engine a few hard revs to see if the fuel pressure drops.


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## halbinath (Apr 29, 2010)

I'll see if I can look into this on the weekend, I think i tried this but I cant remember what the results were, but it does seem strange that it doesn't hold pressure in the line, I took the fuel filter off for a change and there was no pressure in the line. house has a water problem today, and it gets priority.


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