[junkyer]

I have a 1988 Nissan P/U XE 4WD with a z24i engine. Under accerlation or under no load at all it misses, hesatates, or bucks whatever you want to call it at 2750 RPMs everytime. I have a code 51 on my ECU but the manual says it is for v6 engine only. I have been told that it may be the ignitors or ignition control modules for the coils but is there a way to check them before paying out a $100 dollars each? I have fire on both coils it is just seams like there is a rev limiter kicking in at 2750 RPMs. Please help if anyone knows what the problem maybe.

 

[junkyer]

Oh yeah it is TBI

 

[zanegrey]

disconnect the bat for 5 minutes or so.

then start truck. let warm up.

then read codes again

to check coils pull the wires off one at a time to see if they are getting spark..

both sides will spark at idle..

51 is injector circuit.

the wires leading to the inj. have a service loop of sort..

so pull the tape off to the middle of the loop.

that is where the 2 tbi wires merge into 1 wire that goes to the ecm..
it has a copper or brass crimp.

that crimp gets corroded and can lose its contact .. check it..


also check the fusible links for looseness and corrosion..

 

[Nissan HB SS]

2750 rpm skip

Its the Mass Air Flow Sensor. 400 bucks from Nissan. If you haven't fixed it already.

 

[brookwood61]

Mine did that, when the ground on the computer(along with other grounds on the truck). Once I grounded the computer to the floor, it was fine. Go Figure??
Good Luck