intermittent hestitation issue on boost / running rich

I suspect it's the afm or the connector to it is corroded reading a little low across the whole range

what car is your distributor from?

Hows your PCV valve look?

Breathered to atmo
Plenum has a bolt through the opening

How are your vacuum readings? Could be a vacuum leak, or maybe the coil putting out a weak spark. I don't know how the Z31 coils are but I see alot of coils that cut out under load and cause hesitation issues with vehicles at work. Have you changed your cap and rotor?

So I tried the MAF test again as per FSM.

I got to the troubleshooting method below (as shown in picture) and measuring volts from B to D only shows me 8.36 volts. (battery is putting out 12-13v as I checked it also).

Looking at the flow chart diagram it mentions to check E.F.I relay and the harness. What would you guys do from here? Is the E.F.I relay in the drivers kick panel? If that tests good I'm thinking I should pull out my harness and go over it thoroughly.



EDIT: I was reading 8.4 MILLIvolts. It's actually not even giving me a reading.

I've tried 2 different distributors and interchanged Nissan and a Bosch dizzy cap.

I have a brand new rotor and brand new Nissan dizzy cap to try.

Vacuum is over 20. Coil has been tried in the past but will try again if looking into the MAF wiring above does not yield any results.

double post

Swapped a new ECU in a week ago. Haven't had the hesitation issue since.

The previous ECUs had burn marks caused by a faulty fuse in the fuel pump circuit.

are you getting the code 22 fuel pump circuit when you checked ecu codes? I am trying to figure out if this is my problem too. I replaced my fue pump so im assuming thats why the code is triggered.

did you do the fuel pump wiring harness modification?

I followed redz31's website on how to install from his FAQ like a year ago. I dont remeber a wire harness modification. My pump primes for 5 seconds and turn off just like its supposed too.

Could it be boost spike? I had similar problem with full throttle about 3/4 way thru 2nd and 3rd (autocrosses). We changed the boost controller to a custom 1 atmosphere unit and the problem went away. Should also work for a stock 7 lb unit if yours is bad.

I did not have the fuel pump 22 code appearing.

This problem still occurring. The ECU I used just hid the problem a bit. @ 0 boost AFR will drop down to like 9.7:1
As boost builds though AFR goes to like 11-12:1

Thinking about what my next plan of attack is.

I eventually figured out the problem. The chinese turbo I was running blew it's seals within the first 1000-2000km of use. All oil was going through the intake/engine.

Replaced that piece of shit with another spare Chinese piece of shit and the problem went away.

China turbos are best turbos