Ok, so I swaped my 83 ECU for a 85 300ZXT with no problems. The car fired up and idles like a champ. The issues start when throttle is applied. The car coughs and backfires through the air cleaner. To me it's acting like it's starving for fuel. Has anyone experienced anything like this with a swap, and if so, how was it remedied?

 

Did you follow each step of the wiring "to the t" ?

Where did you get your MAF? Was it tested before it was removed from the car?

This sounds like what happened to WreckedJ30 when he toasted his MAF after I did his swap.

 

I followed it to the letter and went back over it multiple times for confirmation.

I got the MAF from a wrecking yard and it was not tested.

From what you are saying it sounds like the MAF could be damaged. If so, is there a way I can test it? Thanks for the help.

 

It may be hard to say, but does the car if you can get it to rev, does it seem to hit a brick wall at 2000 RPM? If so, then it's definitely your MAF. I once left my MAF unplugged by accident, and my car would barely drive.

 

The car will rev, but only if gas is applied very slowly. If I stomp on the throttle the engine will stall, but not die. To me it acts like it is starving for fuel as the throttle is increased. The idle is flawless. This is very frustrating.

 

If the car ran fine before the swap it's the MAF. Take it back to the junk yard & get a refund.

 

After careful thought and much research I have decided to go with Megasquirt and got my quote today. Not to bad on price. Hopefully I will be ordering my system within the next week or so. Can't wait....Only bad part is my Z will be down for a while.

 

All because of a bad MAF? Well... let us know how it goes!

 

I'd say get another MAF at least to drive the Z in the time being, I''d almost say get another MAF and go Nistune. This way you don't have to do anything to your harness. You can keep everything the way it is and control your fuel maps, etc. It's certainly not near the MegaSquirt level, but if you're running a mostly stock setup I'd say you don't really need all the additional spark timing, etc of MS.

 

Duowing under normal circumstances I would absolutely agree with you and stay where I'm at. The reason I'm looking for the change is the problems I'm having with small electrical issues and this 25+ wiring system. On top of this, as with most Z owners, I do plan on eventually modifying the engine and fuel and MegaSquirt seems to be the best bang for the buck. We'll see though, as I am still in the research gathering phase of this change over.

 

I'm actually about to go Nistune myself. Anyway all of a sudden my car is doing this sort of thing. It idles fine, but only when I start the car it will act like it wants to die, then idle really poorly it sputters and pops for a bit, then it all clears up and everything is fine. I'm not getting any codes for the MAF, so I think I'll mess with checking my MAF connections first and go from there. This is annoying. I could probably always pull the MAF out of my 87' ZXT for testing.

 

Check your plugs since you recently did the Seafoam treatment. I usually have to change mine after using Seafoam as they tend to foul out.

 

Hmm, thanks for the info lifegrd, I'd have never even thought of that. I figured it was one of two things, I started messing with the wiring, by putting it into split tubing and stuff, so I was thinking maybe I jerked something or the seafoam really messed something up.

I'm not sure if the problem was taken care of or not. I replaced all my plugs, and when the car started up it seemed kinda sluggish and odd then it sorta straightened out. On the way to a mechanic I knew the car was running kind of odd, right around 2000 rpm it would miss and kinda stumble/hesitate, then it would start to go. Idle was unstable and lumpy. Then I got on the freeway and thought maybe I've got some buildup, or who knows what still floating around that wasn't burned off due to fouled plugs? I floored it ran it to about redline, afterwards when I got off the freeway idle seemed to have smoothed out again.

Anyway I got a nut welded onto my exhaust for the 12mm Titania O2 sensor, so now I just gotta wire it up and then I can run my 86' ECU properly. Gonna order Nistune in a bit here too.

 

Just ordered/made the payment for Nistune. I'm looking forward to that, I'm gonna be ordering a wideband soon to go with it. Right now I'm looking forward to Nistune just to be able to make some good fuel maps to pull better mileage out of this car. I'm gonna be ordering an intercooler and all that stuff soon as well.


Anyway on topic of Z31 ECU Swap, I got my 86' ECU installed, I got the nut welded on for the 3-wire Titania, got that all wired up and hooked up. Man the car runs soooooooooo much better now. That stupid lean surge in the open-to-closed loop transition on warm-up is gone. My idle is smoother, it just seems like I have a bit more power.

Oh thanks again for the plug recommendation lifegrddude that definitely seemed to help. My car ran way better yesterday except for the fact that I accidentally left injector plug 6 disconnected.