# HELP PLEASE 1986 NISSAN D21 TRUCK



## Davis91 (Aug 1, 2015)

Hi I have a 1986 Nissan d21 truck 4 cylinder 5 speed it won't start unless I put fuel in throttle body fuel pump is good has fuel pumping to throttle body but won't start the truck had sat a long time I had it running for like half an hour than bogged out and died wouldn't start back up unless I put fuel in throttle body


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## jp2code (Jun 2, 2011)

Sounds like you have a fuel problem.

The injector(s) could be gummed up, the fuel filter could be clogged, or your fuel pump could be out.

This all assumes you still have fuel in the gas tank.


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## SPEEDO (Jun 9, 2003)

will it stay running once started?? can you hear the fuel pump when you turn the key? have you checked the fuel pressure? replaced f/filter?


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## Greygon (Aug 3, 2015)

I am having a similar problem with a 1992 Nissan Pickup. I checked my fuel pressure coming out of the filter and while it would flow, it registered no pressure on a pressure gauge. I replaced the fuel pump (but had returned the loaner fuel pressure kit). Very noticeable difference on fuel flow coming from filter. Truck still won't start. It will start if I put starter fluid in throttle body. Trying now to determine if it is fuel rail/injectors. 

I also got it to run for 1 day since symptoms started. It sat for two weeks while I was out of town, now back to where it started. Did the filter/pump since that time.


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## jp2code (Jun 2, 2011)

See if there are any codes. If you had a bad crank angle sensor, your plugs would be firing at the wrong time.

Do you know how to check your codes? Here's a demo I recorded for some guys a while back (ignore the torrential rain that attacked me as I was wrapping up my video):

https://www.youtube.com/watch?v=6l7SwU7ZuVk


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## SPEEDO (Jun 9, 2003)

I ran into a issue on my sons Xterra, pointed to a bad f/pump, changed it, still same problem, finally found the problem, it was a split fuel hose in the tank, once the pressure came up the fuel would shoot thru the hole in the hose instead of the injectors.. a big headache turned into something so simple..


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## ajriding (May 10, 2010)

If it runs when you put file in the TB, then you have a fuel delivery problem. How long did it sit? Ethanol will gum up everything. Fuel pump could be too weak, injector could be clogged, fuel filter clogged, hoses bad… Start with the cheap and easy things, then work your way to replacing the more expensive items.


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## Greygon (Aug 3, 2015)

Davis91 said:


> Hi I have a 1986 Nissan d21 truck 4 cylinder 5 speed it won't start unless I put fuel in throttle body fuel pump is good has fuel pumping to throttle body but won't start the truck had sat a long time I had it running for like half an hour than bogged out and died wouldn't start back up unless I put fuel in throttle body


Did you ever get yours running? Couple of notes about where I am on mine and your post:

I don't think fuel goes to throttle body does it? Fuel should flow to the fuel rail, then to the injectors. I found I had fuel all the way through the fuel rail (took off the fuel pressure regulator hose and it flowed from there, it would have to go to the fuel rail to get there). So that seemed to narrow it down to a problem between the rail and the cylinder -- the injectors. 

I picked up a noid light test kit to check signal to the injectors. Both injectors I tried were not getting signal. I did a continuity check on the two injectors and confirmed they had continuity. 

I then pulled the ECM/ECCS to check what was going on -- I had signal between pin 46 and ground -- it was equal to battery voltage -- good sign. But, when I checked signal between pin A on the injector harness and ground, no signal (should have been battery voltage). 

I started messing around the battery positive side and discovered the fusible link at the battery had disintegrated (I should have not gotten signal at the ECM/ECSS, but that was likely just random luck that it happened to somehow have a connection prior to me pulling a bit on the wire and seeing the connector disintegrate). So, I have now ordered a fusible link to replace the bad one. 

Search for the Factory Service Manual for Nissan, that will help you work through the diagnosis of problems.


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## jp2code (Jun 2, 2011)

Good catch, Greygon.

Bad fusible links and a bad ECM are the only alternatives if everything else is working. It is hard to get people to believe that those fusible links go out and cause that much problems.

Just do not eliminate a fusible link with a standard fuse or hard wiring. The fusible link is generally there to protect your ECM, injectors and other electronics if the voltage regulator (built into the alternator) starts going bad or sends a spike through the system. A fusible link is able to attenuate the occasional spike, whereas your standard fuse often lets the spike pass through without blowing.


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## SPEEDO (Jun 9, 2003)

the Z24I/VG30 did not have a fuel rail (throttle body), the KA24E/VG30E does have a fuel rail


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## Greygon (Aug 3, 2015)

Replaced the fusible link yesterday and got the truck running! Now to put it all back together!


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