help for my 86.5 D21

[halfyearD21]

1986.5 Nissan D21 w/VG30i TBI motorYea new to this forum thing so sorry if i dont do everything right. Ok first, does anyone have/know any of the check resistances for the sensors on this truck. Second i need a vacuum diagram for this truck, or an equivalent. Third does anyone know where i can find real performance parts for this motor VG30i, also if there are parts from other motors that can swap (i.e. carbs, intakes). The deal is my truck runs horrible, lots of vacuum leaks, so i am going to rebuild it. I have not really delt with FI before so if there is a way to get a good carb on there that would help me out. Really any information about this truck regaurding swapable parts, performance parts, diagrams, cars that have the same engine, anything to help this rebuild go smoothley. if i do end up keeping the FI does anyone know where i can get a flash for the computer or just a good programable computer for it.Thanks Alot Sorry for so much stuff, SO MANY QUESTIONS!

[halfyearD21]

are you kidding me, nobody is able to answer any of my questions!!!!!!!!i thought there was a "resident tech". if i am in the wrong place for that please let me know

[NM50]

Sorry Bro. I dont live here.First take care of those vacuum leaks.Yes there are performance parts.There is a carb manifold.It's a lot of work for little payoff.Take care of the driveability problems first.Even new those throttle body trucks were not powerhouses.BTW,no reflashes can be done.Try a swap with newer engines if power is what you desire.Hpoe this helps.

[halfyearD21]

where can i find said carb manifold. how much work is it to put it on. i was more looking for a bolt on application, i do not want to jeopardize the integrity of the block by putting more holes in it or anything. so can i get a different computer but same wiring harness from my truck? i found some programable thing from Wolfe Technologies, they call it a POP something or the other. Do you know anything about that? Do you know of any place that deals with these motors specifically? What can i expect from the injectors as of flow? i have many questions

[philipa_240sx]

I was reading you post and the similar one at :

zer...65538

I had an '86.5 Pathfinder WD21 with the VG30i motor for almost 13 years before I sold it. It is reliable if cared for (regular oil changes, timing belt change every 100,000km). No, it doesn't make much power. The biggest issues seemed to be:

- Constant overheating. This was apparently fixed in later models.- Throttle position sensors that fail over time (causes stuttering under acceleration)- Grounding issues with the sesnors & ECU, esp after 13 yrs of Canadian winters- Starter and alternator failures. I went through several.

Vacuum leaks were never an issue with my motor.

I agree with mtcookson, the VG30i is an old motor. Aside from headers, a cam, and EC U upgrade there isn't much out there. You might want to try Autmotive Customizers/4x4 parts: http://www.4x4parts.com.

Regardless, you need to solve the driveability issues first before you start throwing performance parts at an old engine. Start hitting up Nissan dealerships, they might have an old service manual you can pickup for cheap... that's how I got mine. I no longer have it BTW.

Good luck!

Modified by philipa_240sx at 12:26 PM 1/9/2008
Modified by philipa_240sx at 12:49 PM 1/9/2008

[philipa_240sx]

Ebay is your friend. Do a search on ebay.com using the following:

nissan truck service manual

I did a search and there are a few original Nissan manuals for 1988 and 1989 available. Do not worry about the year (86.5 thru 89 are similar) or the fact it shows both the Pickup and Pathfinder. My manual was dated 1988 and it worked just fine.

BTW, don't bother with Hayne's or Chilton's manuals. The original Nissan manual has alot more information.

Good luck.

[halfyearD21]

ok sorry if this sounds rude it is not intended to be. of course i am not going to just start "throwing" performance parts on this truck without fixing drivability problems. i am planning on rebuilding the whole motor and while in that process i am going to then add the performance parts. i am not new to making things with more juice just fuel injection. personally i would really like to get away from it because of all the other expensive crap that i must buy first in order to make the fuel injection work properly, ie throttle position, idle switch, crank postition, all the emission junk (missing 2 pieces each piece valued by the dealer at 200 dollars). these are all things i would like to avoid. i really would like a carb on it, it is easier for me to deal with personally, plus it seems to be a cheaper fix. so if you have any help on that it would be greatly appreciated, also looking for cams, pistons, rods.

[philipa_240sx]

I don't think swapping to a carb will be as cheap as simply fixing/replacing the parts not working on your current motor. There are a few issues you will face trying to do a carb conversion on the VG30i:

1) Manifold for a carb: There is no Nissan VG series motor (that I am aware of) that came with carbs in North America. A search did find a Nissan truck sold in the middle east (think Saudi Arabia) that may have come with a carb. Regardless, these would be difficult to find as you would have to find one and import it yourself.

The carb manifold on the vg30.com site is the only one I've ever seen that is readily available.

2) The VG30e distributor will not operate without a computer: The distributor on the VG30e does not use conventional points or an advance mechanism. It uses a pie shaped rotor that simply directs the spark to the correct plug. The timing is controlled by the computer which fires the ignition coil at the correct time. vg30.com states that a conventional distributor from the carbed Nissan truck sold in the middle east will work for carbed applications. Nissan Motorsports in the USA used to sell this distributor but apparently they are no longer available. Unfortunately there are no other options available.

3) Fuel system: You will have to convert from the OEM high pressure electric fuel pump (about 50psi I think) or use a fuel pressure regulator to get the the pressure down to something a carb can use. The pump is also switched on/off by the computer so will have to modify it to work with the carb.

4) Emissions: The EGR system, evaporative emissions control, fresh air injection for the cat converter, etc are all computer controlled. You can probably disconnect or remove most of this.

5) Transmission control: If you have an auto, there are a few electronic functions (ie. electric downshift control) that may need to be modified to get the transmission to work correctly.

6) Other stuff: Tach signal is from the computer, you will need to add an external one if you want a working tach. The VG had air conditioning and power steering switches that would bump the idle to keep the motor from stalling, you may need to run a higher idle speed to compensate.

This is all I can think of for now. But quite honestly I think you can save a few bucks and maybe some grief by fixing what is broken than engineer a carburetor for your truck. There is no need to buy expensive new OEM parts either when there are probably hundreds of old Pathfinders laying around in salvage yards.
Modified by philipa_240sx at 5:04 PM 1/15/2008

[Perry G]

replaced clutch master cylinder and having trouble getting the pressure to bulid up to bleed any suggestions on bleeding ??? the book says to bleed at dampner and the go to the release cylinder.