Don't want to give up on my truck need your help!

[JaySean]

I have an 85 nissan 2wd 2.4 pickup. Ran wornderful. One day started running very rough. Hard to start, would not idol till warm. Hesitates and stalles. I repaced all the vacuum lines, the fuel pump, fuel filter, checked the filter in the fuel inlet to the carb, removed the fuel check valve. Didn't work, so I replaced the cap and rotor, sparkplug wires, both ignition coils, spark plugs are good and had the timing set. It starts up fine now, auto choke is working properly. I can run the truck it seems like as long as I want and it will run pretty good other than a little surging when cruising at a constant speed say fourth gear at 45-50mph, but when I shut it off and go to start it a couple hours later, that's when it runs very rough. Idol is off, hesitates, bucks, stalls, as if not enough gas getting up to the carb. Now if I turn up the fuel mixture on the carb and turn up the idol, it runs way to rich and I don't want to run it that way, but it no longer stalls, which leads me to believe its a fuel problem somewhere. I thought well maybe its the ecc relay. The haynes manual says the control unit regulates the amount of fuel that is injected, as well as the ignition timing idle speed, fuel pump operation and feedback of the mixture ratio and does not operate in open-loop condition when engine is cold. I feel like what I am experiancing relates to all of this, but I hooked up the relay to the battery it seems to be working(I hear it click). The fuel pump relay is good also. I am aware of the shut off relay under the dash on the passanger side above the speaker. Is there a way to test if its working? And where can I get a new one? I don't see any cracks in the sodering anywhere. I am at a loss right now and don't know what the next step would be. Why does the truck run fine till I stop the engine and try to run it later on? Anyone have any clues?

[flinterman2000]

If there are no emission controls where you live I would suggest you change the carburetor to a webber. 32/36 usually works efficiently but you will have to do a lot of tuning to get it to work as it should.

[PEZi]

I am aware of the shut off relay under the dash on the passanger side above the speaker. Is there a way to test if its working? And where can I get a new one? I don't see any cracks in the sodering anywhere. I am at a loss right now and don't know what the next step would be. Why does the truck run fine till I stop the engine and try to run it later on? Anyone have any clues?

That relay is about $50 and is easy to replace. My truck did a lot of this same stuff, and replacing it fixed it. As far as other things it could be as far as stopping your engine and then having issues re-firing, I feel like that is most likely related to vapor lock, or at least something of the sort.

[JaySean]

So it turned out to be the wiring harness into the computer wasn't making a good connection. I cut a piece of credit card and propped the wiring harness up a little. It made better contact and at least doesn't stall anymore, but while cruising in 4th or 5th barley touching the gas it starts to feel like it's missing. If I give it more gas I don't notice anything. If I have it parked and hold down the gas at just the right spot, it starts cuts out for just a second and then revs back up to where im holding the throttle. Any Ideas what's going on now? Is the computer just shot and barley allowing the truck to run right?

[AZhitman]

JS, do you have a copy of the factory service manual?

Good to have - I'll try to add more info tomorrow, it's late.

http://www.nicoclub.com/datsun-service-manuals

[JaySean]

I have a Haynes manual.