[BSERIES18C407]

• Sup people's new to forum/ Nissan's so kinda learning how they work, got a 89 SE 5spd bought with tired motor so swapped in a 2000 xterra/pathfinder vg33e not sure which one but has always been in limp mode from day one code 51 after purchasing injector,dist,ecu with no luck, understand the injector/tbi operation but couldn't find anything wrong injector circuit,so just went and installed 33 motor and swapped all sensors/eng harness over, it ran but with same issue unfortunately it took a drive in it too find out problem remains but this time had to pull back home after analysing everything i found my fuel pump isnt priming or injectors aren't spraying well after many many many weekends spent up stupid late tryin to figure this shit out before i blow a gasket and put a stick of dynamite under the gas tank this my last chance of ever getting this thing running have owned it 3yrs know and drove it maybe 4 times, (so ashamed of myself ) !! But i dont quit easy and could've long time ago but to prove everyone i know wrong about it being worth the trouble i want this thing to run like it should be with the record of dependability they're known for hell wouldn't mind getting the late 80's single turbo manifolds and boost it being most my friends got full size chevy and fords lol but like to be different rather than follower any help greatly appreciated fella's.

 

[jp2code]

Unplug the injectors, one by one, and see which one doesn't cause a worse condition. Replace that one.

 

[BSERIES18C407]

Unplug the injectors, one by one, and see which one doesn't cause a worse condition. Replace that one.

Its a tbi setup original engine was vg30i so there's only 2 injectors but aside from that ecu isnt powering up upon ignition being turned on so injectors isnt firing fuel pump isnt priming but if i unplug i believe furthest plug to the right if on passenger side looking at ecu service manual says to attach pin#6 blu/red wire to a ground to check something else but when i do that ecu will come on but unfortunately the plug isnt isnt pluged in with remaining other wires that are in it. Why has this been such a nightmare smh thanks for pointer though appreciate reading my issue.

 

[rogoman]

There's a fusible link that may have blown. Check for 12v at the safety relay. Here are two pictures:

:

 

[jp2code]

After checking the fusible links, check the fuses to see if the one going to the ECU is good. The ECU controls when the injectors fire. If it doesn't work, your engine will not crank. If you are not going to use the ECU, you will need to do a Weber carburetor swap.

 

[BSERIES18C407]

Man i think tried so many different things i cant even think of what im doin anymore, ive got the fsm and did everything it says and yet the problem is still current, i just figured out if i jump 2 pins on main relay with it unplugged ecu will come on fuel pump still not priming but ecu works so i did the main relay procedures and all checked out ohmed the relay itself and again checked out so it seems somehow there's a grounding issue in regards to ecu/relay not working but it would lead me to think something with my key ignition switch possibly? Is this a possibility maybe im not one to give up especially when its my money dumped into it but im on my knees just about and sometimes wanting to light a stick of dynamite under this nightmare, until i catch some air along with a break from it , and the carburetor was a thought but its not practical enough as far as weather changes but was thinking hard about it sorry for long reply just beem trying everything possible so appreciated you guys getting back at me with help.

 

[BSERIES18C407]

There's a fusible link that may have blown. Check for 12v at the safety relay. Here are two pictures: View attachment 6343 :

View attachment 6342

Tried this and to my knowledge everything checked out,but safety switch this is what i did to figure out 51 code truck has had from day one with original engine in place.

 

[BSERIES18C407]

Will look into safety switch though and let you guys know what results are.

 

[jp2code]

I have heard a lot of owners talk about the ignition switch going out. It would seem odd that it's failure would coincide with your engine swap. Possible though.

 

[BSERIES18C407]

Ive heard similar things something about ģround signaling,but aside from this as luck would have it, i was about to wrap up for the night and due to my devotion to figuring out why ecu wont come on i decided to try one i bought at the time i was trying to figure out the infamous code51 which at present time the legend continues on to the jdm vg33e currently in truck, to plug ecu in and see if same results occur, and wouldn't you know dame thing comes on, smh so some where along this nightmare the original ecu got burnt or something, which strange being everything thing ive tried has been from the fsm but that's good news and a progress, unfortunately no good story ends with a victory, dam fuel pump still isnt priming and ohmed relay checks out, checked voltage supply at relay inputs also checks out so what am i missing fellas? Also code 51 haunts over truck still which at point of converting to mpfi more efficiency and power from engine made when all problems are fixed of course any ideas to why relay isnt doing its job for fuel pump ? (Yes fuel pump works and yes fuses are good) so thats crossed out any help greatly appreciated guys.

 

[rogoman]

Ive heard similar things something about ģround signaling,but aside from this as luck would have it, i was about to wrap up for the night and due to my devotion to figuring out why ecu wont come on i decided to try one i bought at the time i was trying to figure out the infamous code51 which at present time the legend continues on to the jdm vg33e currently in truck, to plug ecu in and see if same results occur, and wouldn't you know dame thing comes on, smh so some where along this nightmare the original ecu got burnt or something, which strange being everything thing ive tried has been from the fsm but that's good news and a progress, unfortunately no good story ends with a victory, dam fuel pump still isnt priming and ohmed relay checks out, checked voltage supply at relay inputs also checks out so what am i missing fellas? Also code 51 haunts over truck still which at point of converting to mpfi more efficiency and power from engine made when all problems are fixed of course any ideas to why relay isnt doing its job for fuel pump ? (Yes fuel pump works and yes fuses are good) so thats crossed out any help greatly appreciated guys.

You just said that when you replaced the ECU, the truck started up. In that case the fuel pump is working. So what is the actual problem at this point?

 

[jp2code]

Relays go out. Try putting 12V across the terminals and see if the relay clicks on.

 

[BSERIES18C407]

You just said that when you replaced the ECU, the truck started up. In that case the fuel pump is working. So what is the actual problem at this point?

Quote= ECU COMES ON DOESN'T SAY ENGINE IS RUNNING OF WHICH WAS NEVER STATED,however i will repeat again incase someone else is confused for some odd reason, was having issues with fuel pump priming initially upon diagnosing this problem somewhere along the the ecu suddenly stopped working (dont know how this happened or exactly when because was focused on relay's and fuse links etc. After realizing that started checking why it didn't come on (power,grounds, what fsm procedures called) then before was finished for the night i looked at another ecu i bought when original engine was in truck and having code 51 problem which after ecu,distributor and new injector bought still continues on with current engine but is reason for having second computer to have and plug in ?

 

[BSERIES18C407]

Relays go out. Try putting 12V across the terminals and see if the relay clicks on.

Ok so basically add 12v to the relay itself to verify it makes click sound, ok cool will let guys know results just at moment i got truck at a storage facility cause HOA doesn't allow mechanic work and when installing engine was only choice bur know this Coronavirus bull shit limits time to do alot married with 3 teenagers so hard to disappear for some automotive session's smh but will check out and thanks again for the help.😏

 

[jp2code]

After realizing that started checking why it didn't come on (power,grounds, what fsm procedures called) then before was finished for the night i looked at another ecu i bought when original engine was in truck and having code 51 problem which after ecu,distributor and new injector bought still continues on with current engine but is reason for having second computer to have and plug in ?

I think you might have a slew of issues going on, and it sounds like you kept making unrelated changes when you had issues, and now your system is all fuked up.

So with the VG33e engine, did you use your existing throttle body injection system or are you trying to get the VG33e engine's multiport injection system to work in your 1989 truck?

When you mention the multiple ECUs, which 2 do you have?

 

[BSERIES18C407]

I think you might have a slew of issues going on, and it sounds like you kept making unrelated changes when you had issues, and now your system is all fuked up.

So with the VG33e engine, did you use your existing throttle body injection system or are you trying to get the VG33e engine's multiport injection system to work in your 1989 truck?

When you mention the multiple ECUs, which 2 do you have?

Lol it probably would seem this way if reading this essay of things done but very mechanically inclined and have done more swaps than i got fingers unfortunately these are hondas and a friends f150 which helped him install a 351 out of a ski natique boat, but have no actual experience with Nissan's even though have decent amount of knowledge of the stupid fast jdm engines sr16/20vet,rb25,26det etc. But as for what i used for swap is basically everything from the original engine only head,block and front accessories- pwsteering,ac and alternator everything else is original from truck but has thousands of grounds from what i can see and being 1989 it shows it ive gone threw as many as i can find cleaning surface and cleaning copper surfaces but its the little things that those familiar with these trucks common issues that need to be addressed and its these things that im trying to address

 

[jp2code]

If the Nissan Hardbody has a code stored in the ECU, the trucks will run in limp mode until the codes are fixed.

 

[BSERIES18C407]

Wow its been for ever it seems !! Sorry so long but did some testing on that relay buisness and fuel and main check out fine and at this point 2nd computer is working fuel pump is priming when ignition switch is turned on, and if squirt some fuel into throttle body motor fires up immediately until fuel is burned and then quits. So injectors arent firing but are getting 12v and obviously getting spark since fires up if fuel is added so now its its something the computer isnt receiving like signal or something also my tachometer barely moves whenever attempting to start it without adding fuel. It should clearly be moving whenever engine is cranking correct?

 

[BSERIES18C407]

Oh and as for question about engine codes i cant get it to run so not sure if there could be a code generated could it ? But the only code ive ever gotten is 51 and well before with old motor it would start without a problem just wouldn't rev past 2800. So this problem is still around but been told it could be oxygen sensors and coolant sensor thats causing the ecu to see something it doesn't like so it enters limp mode just cant do anything if wont even start and run so im in the dark on the injector circuit crap, anything that can help with mystery truck would be greatly appreciated guys.

 

[jp2code]

The injectors could be blown or shorted. When you apply 12vdc to an injector, you should hear it click as the coil inside it is energized and the injector opens. It should click again after you remove power and it closes.

Also check the resistance between the terminals. The newer injectors expect 12 to 14 Ohms, but I think that the older ones like you have should be around 6 Ohms.