Having issues with the Following, working with my son on a 1984 Nissan/Datsun 720 pickup. Did an engine swap original on was bad, found one that was running in a parts vehicle at a local junk yard for $600.00 was told it s a 1985 but found out it was and 1986.5 with a different distributor and wiring. My question to all the experts, what do I need to do to correct this issue.

will be great full for any information. Thanks

Hey, welcome to NICO Club! I think you either use the old distributor with the old computer in this new engine or use the new distributor with the new computer and new engine. IF the yard who sold you the engine has sold you the wrong stuff or mislabeled it of their own fault, they may have the proper engine computer and they may just give it to you as apology for their mistake. If there is no such liability on their end, you may have to pay for it or seek out another one. I don't think there are too many differences between 84 and 86.5 as far as technology goes. What physical differences are you finding? Anyway, if it were me, I'd probably try my older distributor so I could use my older engine harness and computer.

Thank you, The distributor are some what different except that the 84 had 3 wires going to a junction box over by the vacuum canister. Were the 86 has a 4 wire snap connection plug that goes to the wire harness over by the windshield fluid reservoir. The 84 distributor has a fork connector at the end of the shaft which goes into the engine block. The 86 has a haft moon 12 point spindle at the end of the distributor shaft.

A person I talk to locally said I need to change out the oil pump to correct the issue. gathering of the information I need to continue on my sons 1884 720 pickup.

Well, to help with your research, you might want diagrams and such. We have a factory service manual for the early 720 under Datsun Service manuals and we have the newer Hardbody under Nissan Service Manuals. The years are close, but not a perfect match to your years. I put links to the two I think you need and a link to the overall in case you'd like to search for other years and compare information.

1982 Datsun 720 - http://www.nicoclub.com/service-manual? ... e%20Manual

1988 Nissan Hardbody (each link is a chapter) - http://www.nicoclub.com/FSM/Hardbody/19 ... %20manual/

All FSMs we have available - http://www.nicoclub.com/archives/use-ni ... abase.html