Originally I discovered that fuel wasn't pumping thourgh the filter...replaced the filter. No improvement. Checked the fuse...ok. Checked the relay...ok. Tested for electrical power to the fuel pump...ok. Dropped the fuel tank and replaced the electric fuel pump. Still no change...won't start. Oh, and I also made sure that the fuel line from the tank to the engine wasn't plugged. Occasionally I can bypass the fuel pump relay and the engine will run for only a couple of minutes, but now it won't even start doing that?

The trouble shooting guide instructs that the diagnostic code is flashed by the red and the green LED on the E.C.U. I.e. Two red flashes followed by three green flashes equal the numer 23. Only the red OR the green light is supposed to flash at a time. On my pickup BOTH the red LED and the green LED flash simutaneously!?? Not only that, they flash too many times. The code numbers that are being flashed by both the red and green LED's simutaneously are these:

One long flash.
Two long flashes.
Three quick flashes.
Four quick flashes.
Five quick flashes.

I'm baffled. I had a Nissan mechanic come over to check. Without telling him anything, and me wanting to see what conclusions he came to, he said that the fuel pump was defective? I don't think so. I suspect that the ECU is defective, but I hate to spend the money on that very expensive part only to find out it wasn't defective. The fuel pump was bad enough...$135! Does anyone have any ideas? I'm completely out of ideas!

man i feel for you! i have an 88 with the Z24 an it is the shits when something goes wrong. i think its the computer myself but hey you never know. see if you cant find one at a wreckers.

my ultimate piece of advice is to take the truck out to the back fort, get yourself some C4 and see how big of an explosion you can make!!

Good Luck!

Yeah, bought the truck brand new and it's been trouble free until this problem occurred. Just can't figure it out? Pretty bad when a Nissan mechanic comes over to my house and can't figure it out either! I 'll just have to keep my eyes out watching for a Nissan pickup truck to appear in the wrecking yard and grab that computer. I wonder if the computer in the Pathfinder is the same one? I'll go look at the Pathfinder that was there last week.....one lousy '95 Nissan out of about 600 cars in the yard! That should indicate that Nissans are usually good running.

as long as the pathfinder had teh same motor and tranny (dont even know if thats necessary) the computer should work. good luck man!

Okay...the latest: I figured what those 1-2-3-4-5 flashing was. It was the "modes." Okay, I went to mode 3 and the computer flashed the Diagnostic Trouble Code "42." Great, I thought! Another problem: No such diagnostic code as 42? {gritting my teeth and pulling out my hair again!} There is a 41 and a 43, but no code of 42. I'm sending the computer in for testing and possible rebuild. The rebuild is 1/3 of the dealership price for a new one. I'll keep everyone posted on the final outcome.

good luck, hopefully all goes well. did you ever actually figure out what the problem was?

Right before I boxed the computer up to send it in for testing, I decided to snoop around the internet a bit more. Glad I did....there is a bunch of more codes than in the repair manual. Turns out that diagnostic code 42 is a problem with the Fuel Temperature Sensor. That $37 part will be in on Wednesday, but I probably won't be able to have the time to install it until Sunday. I sure as hell hope that fixes the problem!

out of curiosity, where did you find the diag codes? if you could pass on the website that would be great man thanx!

http://www.troublecodes.net/Nissan/88-9495pthqust.shtml

Copy and paste this to your browser. From there you can also go to other models and years of Nissan, and I suppose other brands of vehicles too. Ihnteresting that this is a more complete listing of Diagnostic Code than in the repair manual??

... Ihnteresting that this is a more complete listing of Diagnostic Code than in the repair manual??

is this a statement or a question? lol

Latest update: Dropped the fuel tank and replaced the Fuel Temperature Sensor with a brand new one. The computer code now is 55. 55 is "No fault codes in memory." Okay, no fault code in memory now but the damned thing still won't start!!! I assume that it's in the wiring somewhere. In the mean time I have to ride my motorcycle to work!

I finally gave up trying to diagnose the problem and gave it to the dealer to fix. As of this posting, the dealer has had the truck for FOUR WEEKS, and still cannot find the problem!

Per the service writer: "It isn't pumping fuel but we don't know why?" ....."The fuel pump is defective, but the new one (it was a new one!) still doesn't work?.... "The wiring harness checks out okay but nobody can find the problem." ...Every mechanic in the shop has had a look at it but nobody can find the problem." ...."The wiring in the fuel tank is fried, that's why the pump doesn't work." (Oh yeah? It wasn't fried when I replaced the fuel pump AND wasn't fried when your man replaced my new fuel pump?)...."We still can't get it to pump fuel, so the computer is defective." (Gee. What happened to the second new fuel pump?)....."We sent the computer out for repair." (That was two weeks ago)

It's apparent that the "experts" at the Nissan dealership still haven't a clue as to what the problem is. I look forward to discussing the final bill with the service manager and how he plans to justify his charges.

Okay....the final outcome. I feel that the dealership service department lacked the expertise to diagnose the problem in a timely manner. Also, the parts mark-up seems excessive. But considering that I couldn't figure out what the problem as, who am I to complain? The service department replaced the new fuel pump and justified that by saying that the wires were shorted. They weren't. The positive terminal push-on connector looked overheated. Don't know why? Maybe it was a loose connection to cause that? Also, I was advised that the (new) pump was defective. I got it home and checked it. It worked just fine? They replaced the entire fuel pump assembly. That included the fuel gauge sending unit. But like I said: I had given up and now I have no room to bitch about any charges. They say that hind sight comes cheap. I could have had the computer rebuilt for $225 in Sacramento by a company that specializes in such repairs. Anyway, this is the breakdown on my invoice. So that other's may learn.............


LABOR CHARGES:
Check system and advise................................$170
Replace fuel pump..........................................$170
Check computer for failure..............................$127.50
Replace computer.......................................... .$42.50


PARTS CHARGES
Fuel pump assembly.......................................$24 0.93
Tank O-ring.............................................. .....$11.24
Used computer.......................................... .....$620.00


Sales Tax............................................... .........$67.16

Grand total............................................. .....$1,487.70

ouch!!!!

thanks for posting so much...helps increase the utility of these forums.

- matt

Oh, I forgot to mention that the dealership also removed an anti-theft device that their sales department had installed to all the new cars that they sold during '95. The service manager stated,"<<we've had some problem with that system.>>" I remember my sales contract indicated that the "system" cost $500 on my new car contract. Later, I discovered that the same "system" sold for $125 on the internet. I wonder if their previously install "anti-theft system" may have been the problem too? Nothing would surprise me too! The system was designed so that if you removed a "key"...actually a sort of computer tab, the engine wouldn't crank but the ignition would come on. Gee, how much trouble would it take to push start a little Nissan truck? At the time, every car and truck on their lot had that system installed by their service department, otherwise I would have declined to have that junk in my truck.

so have you gone down to the dealership and ripped them a new one yet??? cause at the garage i used to work at, if you came in with a problem and they told u 'a' was wrong and fixed 'a' but it didnt work, u didnt pay for it. didnt matter what they did if it didnt fix the problem u didnt habve to pay for it.

No I didn't because I was told that it would be time and parts. Oh, I suppose I could have gone and raised hell, but I did get a look at the time stamps of four mechanics that added up to over 10 hours. Too bad they either didn't have the knowledge or the test equipment to do the job, but by this time I was just glad to get the truck running. In the mean time I'll occasionally check the wrecking yards for a '95 Nissan pickup and gab that computer for a future spare.

Okay, more on the Fix. I was getting an average 22 mpg fuel consumption ever since day one as a brand new vehicle. With the last two fill-ups (since getting the truck back from the dealer) the mileage was 27 and 28 mpg. That didn't make any sense with me? I pulled the spark plugs to check the condition to determine if the engine was running too lean. The plugs look normal? Engine temperature remains in the normal range with the air conditioner going on hot days. So now I'm wondering what everyone else is getting for fuel mileage on a Nissan 4-banger? What is the normal fuel consumption?

Hey Doug,

Hope you're still a member of this forum... my 95 nissan pickup is giving me trouble code 42 as well. I pulled the fuel tank and found two wires with nothing at the end, presumably for the fuel temp sensor. Was your sensor loose in the tank as well? Also, where did you find a replacement sensor? I can't find one anywhere.

Thanks!

Chris

The problem with the computer was that the circuit that grounds the fuel pump to make it operate went bad. Rather than spend the big bucks to replace the computer, next time I will simply trace the grounding wire back to the relay in the engine compartment (or to the computer itself). From there, I think wiring in a solenoid that will ground the appropriate wire would be a lot cheaper than spending $600 bucks for another computer.

No wonder it was so hard to fix! My truck runs just fine, the problem is the check engine light is coming on so I can't smog it. It gives me trouble code 42, which is of course the fuel temp sensor. I pulled the fuel pump assembly and found two wires dangling in the fuel. My best guess is the fuel temp sensor used to be attached to these wires. I can't find documentation on it anywhere, nor can I find the part! What was your experience when you replaced this sensor?

Thanks!!!

That temperature probe has to be somewhere in the gas tank? It didn't dIssolve? In my case, I had replaced everything in the fuel tank, which didn't correct the problem. Only after the installation of a used computer did the engine start. I got ripped off by the dealer who charged me $800 in labor to locate the problem plus the $600 for a used computer!!! Had I known about the grounding, I would have put together a relay operated by the ignition switch to ground the fuel pump. It is said that hindsight come cheap. Sure wish I knew about the fuel pump grounding to operate the pump before getting ripped off. Actually, it was my wife who paid the bill while I was working out of town. I think women are easier targets for repair shops.:mad:

I found it! The probe was mounted near the rear of the tank. The wires had just seperated at the soldering joint. I soldered it back together, reinstalled everything, no more check engine lght! Just passed smog :)