Hi everyone, I am brand new to this forum. I came across it while doing a search looking for ideas to my problem. I read through alot of the existing threads but did not quite find one that is similar to my issue. Here is the problem:
While driving I lose fuel pressure. I can press the gas pedal down as far as it will go and it seems like there is just no pressure there. Eventually the truck will either die or I have to kill the engine and then restart it to get the pressure to come back. It seems if I let the truck sit for a day or two I can drive farther before this happens. I let it sit all day yesterday and was able to drive about 20 miles this morning before it started happening again. So far I have changed out the fuel filter, the fuel pump, the valve assembly kit that sits right above the gas tank and this morning had the catalytic converter changed out and the gas cap ( Auto Zone guy thought I might not being getting good pressure from my old one.) About the truck, it is a stock 1995 truck, 2wd with the stock/standard 4 cyl engine. Does anyone have any ideas as to what might be causing this? This is my 3rd Nissan and I have never had any problem like this is the past.
Any ideas/tips/thoughts will be greatly appreciated.
While driving I lose fuel pressure. I can press the gas pedal down as far as it will go and it seems like there is just no pressure there. Eventually the truck will either die or I have to kill the engine and then restart it to get the pressure to come back. It seems if I let the truck sit for a day or two I can drive farther before this happens. I let it sit all day yesterday and was able to drive about 20 miles this morning before it started happening again. So far I have changed out the fuel filter, the fuel pump, the valve assembly kit that sits right above the gas tank and this morning had the catalytic converter changed out and the gas cap ( Auto Zone guy thought I might not being getting good pressure from my old one.) About the truck, it is a stock 1995 truck, 2wd with the stock/standard 4 cyl engine. Does anyone have any ideas as to what might be causing this? This is my 3rd Nissan and I have never had any problem like this is the past.
Any ideas/tips/thoughts will be greatly appreciated.
Thanks,
darth
Why are you sure that it is the fuel system? All you're saying is that you are gradually losing power. Before you replace other parts you need to step back and think the problem through.
1) Is the "check engine" lamp on? If it is you need to read out the code (1995 is probably not an OBD II system. You can probably have the auto parts store read the code or there may be ways to read the code with a simple meter).
2) Any backfires? Backfires out the exhaust generally indicate a rich condition (could be caused by a misfire). Backfires out the intake generally indicate a lean condition.
3) It sounds like you've replaced the obvious fuel system items. Can you measure the fuel pressure both standing still and while you are driving?
4) You've changed some exhaust system parts (the converter). This suggests that you think there is a back pressure problem in the exhaust. Have you inspected the exhaust system for obstructions (like a potato in the tailpipe), kinks, and dents?
5) Any vacuum leaks?
6) How many miles on the truck? The 4 cyl. engines are kind of weak in their EGR systems. I'd check function of the EGR valve.
7) Are you very high (say > 150k) for mileage? If so I would not rule out the timing chain.
8) I'm less inclined to think electrical or ignition but it's not impossible. A weak coil may be temperature sensitive and cause misfiring.
Steve and Dave, thank you both for replying back. Steve, I am/was thinking it was a fuel system problem mainly due to advice from friends and the guys at the local Auto Parts store. When it first started happening I was told to change out the fuel filter. I did that and the problem still existed. The guy at Auto Zone suggested I tap the bottom of my gas tank with a hammer and see if that cleared the problem for a bit. I did this and sure enough it seemed to work for a short while. It was then suggested to me that the fuel pump is clogged and I should change that out, so I changed it out. While I had the gas tank dropped I noticed a filter/valve that was above the gas tank. I took this off and replaced it as well, just for good measures. After doing all of this the problem still existed. So I asked the guys at the Nissan dealership, where I had to buy the small filter/valve at and they suggested to replace the catalytic converter. Now for your questions.
1. The check engine light is on. I took it to Auto Zone and O'Reilly's, neither of them can read it due to the age of the truck. I have since learned of away to read the "blinks" which I plan on doing this weekend.
2. I have not had any backfires as of yet.
3. I do not have the toos to measure the fuel pressure. But I am going to have a garage analyze it for me as well as hopefully tell me what I need to replace to fix the problem.
4. I have checked the exhaust, I actually thought the same thing, but it is all clear and the muffler guy told me he was impressed at how "clean" everything underneath it looked for its age.
5. I am not sure about vacuum leaks, is this a test I can do myself?
6. The truck has 181k on it. I have not looked into the EGR system yet. Can you tell me what I need to look for by chance?
7. Yes sir, very high mileage.
8. I was thinking of changing the engine coil as well as the rotor and distributor cap, but I think I am going to wait until I get the mechanics opinion. What do you think?
Dave, I am not exactly sure where the fuel pressure regulator is. Can you advise me please?
Steve and Dave, thank you both for replying back. Steve, I am/was thinking it was a fuel system problem mainly due to advice from friends and the guys at the local Auto Parts store. When it first started happening I was told to change out the fuel filter. I did that and the problem still existed. The guy at Auto Zone suggested I tap the bottom of my gas tank with a hammer and see if that cleared the problem for a bit. I did this and sure enough it seemed to work for a short while. It was then suggested to me that the fuel pump is clogged and I should change that out, so I changed it out. While I had the gas tank dropped I noticed a filter/valve that was above the gas tank. I took this off and replaced it as well, just for good measures. After doing all of this the problem still existed. So I asked the guys at the Nissan dealership, where I had to buy the small filter/valve at and they suggested to replace the catalytic converter. Now for your questions.
1. The check engine light is on. I took it to Auto Zone and O'Reilly's, neither of them can read it due to the age of the truck. I have since learned of away to read the "blinks" which I plan on doing this weekend.
2. I have not had any backfires as of yet.
3. I do not have the toos to measure the fuel pressure. But I am going to have a garage analyze it for me as well as hopefully tell me what I need to replace to fix the problem.
4. I have checked the exhaust, I actually thought the same thing, but it is all clear and the muffler guy told me he was impressed at how "clean" everything underneath it looked for its age.
5. I am not sure about vacuum leaks, is this a test I can do myself?
6. The truck has 181k on it. I have not looked into the EGR system yet. Can you tell me what I need to look for by chance?
7. Yes sir, very high mileage.
8. I was thinking of changing the engine coil as well as the rotor and distributor cap, but I think I am going to wait until I get the mechanics opinion. What do you think?
Dave, I am not exactly sure where the fuel pressure regulator is. Can you advise me please?
Thanks again guys.
darth
Darth,
1) I agree with Dave that the fuel pressure regulator is suspect if the problem is truly in the fuel system. Only a pressure test will let you know for sure.
2) The first think I would do now is read out the check engine light. That will give you an indication which system is suspect (fuel, EGR, ignition, etc.).
3) As far as vacuum leaks, listen for a hissing sound while the engine is running. If you think it's a gasket betwen two part you can try to "shoot" some carb cleaner at the spot. If there is a vacuum leak the engine may speed up a little. You can also use a vacuum guage to measure the manifild vacuum. I'm not sure what is normal for these engines but I'd guesss greater than 15 inches of mercury at idle.
4) I'd leave the EGR system alone at the moment until you get the check engine code read out. If the 1995 is like a 2001 the EGR valve is kind of a pain to remove.
5) Again, I'd standby on replacing the ignition parts until I read out the check engine code.
go with Steve on checking the ECM for codes, one of the stickies under truck/suv will walk you through checking for codes on an OBD I system (which is what you have). Autozone and Oriellys only checks OBD II sys. get a repair manual, this will help diagnose things like testing fuel pressure and vacuum leaks. if you can get a FSM (factory service manual) would be helpful also. everybody starts out with no or limited amount of tools, just buy or borrow the ones you need. I think Napa will rent some tools (dont remember). the fuel pressure regulator will be on the fuel lines close to the throttlebody possibly mounted on the firewall or rear top of motor.
__________________
Dave
96 4WD XE Reg. Cab ka24e
Calmini 3" SL, Steering, Lock-rite rear, LSD front
Thanks for all of the info guys. I am going to take it into the shop on Friday. I have found a mechanic who will read the codes for me and diagnose/analyze the problem. He is charging 60 bucks which from calling around sounds like a fair price and I have had 3 people recommend him as being fair and honest. I will post what he says as well as what finally fixes it.
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