Barely runs, pig rich, after socketed '88NA ECU swap. HELP?!

Sounds like I was mistaken on ECU choice then. I was under the impression that if a guy added dropping resistors everything would be fine. I mean Hell, its on Jason's site as a write up.

It makes sense if the low impedance injectors require a faster reaction time and the high impedance ECUs are slower, it'd hold the injectors open longer and flood the engine. I ohmed the injector grounds anyway, 7.5ohms.

Now, I don't have Nistune. Just socketed for it with a stock tune on the EPROM - if it makes a difference.


Any thoughts on the MAF and CHTS codes and why the engine can redline without the MAF?

i think by stone tone you mean stock tune just the capability of removing the stock rom and putting the nistune board in if you feel later, right?
either way, like i said - I do remember some having success with injectors resistors only… but there is definite latency difference on the maps.

thats why i don't think i'd ever bother running an ECU that requires resistors. I'd rather run one that has the capability of both high and lo z.

Correct, just a removable chip.

Yeah that makes sense. I'm retarded lol. There I go thinkin' again!

are you sure you socketed the board properly? it's very tough to work on nissan boards because the pads lift VERY easily, and once you do that, you have to jump wires to surface mounted devices, which sucks balls.

any one of those pins acting weird will either make the car not run properly or act really weird.

I didn't socket it, I wouldn't trust myself and my soldering iron is way to big for that.

Have you verified that it's running the correct map?

I've tried two other EPROMs.

I took the truck for a drive real quick to see what it would do for shits and grins. Its got a fucking shit load of power, under half throttle. Full it sputters and pops, but half throttle feels like normal full throttle lol.

I think I'm being sent another ECU today.

ok… so the car runs fine but not at full throttle? unplug your o2 and change your distributor and ptu to a pwr-2.
just try it if you have spare parts lying around. sounds like my issue with my maxima distributor i had. switched to 88 z31 and it was fine.

Shouldn't rev over a certain rpm with the maf unplugged. I would look into that if this is unchanged after you try another ECU. My shit won't even start without it.

No. It doesn't run fine at all. Its as rich as it can get, but just happens to drive okay in a very narrow throttle/RPM range. I don't have an O2 sensor and I have the correct dizzy. Remember Careless, the truck ran perfect before the ECU swap.

I couldn't believe a Nissan revved out without a MAF. Weird as shit.

Order of operation: Drove good running truck into the garage, removed '84NA ECU, broke it, installed dropping resistors, installed socketed '88NA ECU with stock '88NA tune, truck barely runs and won't idle unless I induce a huge vacuum leak.

I made a video, this is with the MAF unplugged. Plugged or unplugged there's no difference. when its idling I have my foot on the gas.

https://www.youtube.com/watch?v=BQJBZhXOZts&feature=youtube_gdata_player

Haven't seen the video(I'm at work) but if the ECU is not reading the MAF how will it know how much gas to i ject into the engine. I believe the ECU is functioning properly. Your wiring is incorrect. Faulty wiring is fooling the computer. Until the system go into limp mode when MAF is unplugged…ya shit ain't correct. Fix or buy…I have a nice 85 harness.

We shall see when I get the new ECU. Like I said I have tested the wiring many times and there's nothing wrong with it. The ECU isn't going in to limp mode, unless the '88-'89 ECUs don't have the 2,200RPM limit when in limp mode.

If there was something wrong with the harness this thread would not exist as the problem would have been fixed long ago. I wish it was the harness.

The truck ran perfect before he pulled the ecu. I heard it run the other day and went over there to listen to it. It runs just like it would with the incorrect tune like a jwt tune or something. Seems as though latency is way off......