rx_prez

Well I posted this in the 2nd gen forum a while back, but since there is such a high volume there I figured I may have more success here, among the smaller community of Canadians. Let me know what you think, any help would be appreciated -->running out of ideas

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/engine-dies-giving-gas-idle-444052/

thanks,

Dave

Amur_

Does this happen all the time or only under load?


Throwing out some ideas...


I didn't see air filter listed in there. Have a K&N? Clean it.


What about air intake passages (meaning before the air fiilter)? Maybe the poor girl inhaled a newspaper or something. Have a look.


What about voltage *at* the injectors when you step on the gas? HAILERS can guide you on how to check that.



The preceding technical advice was not authorized by RXcetera. Ya pa-pa!

rx_prez

It does happen all the time, under load or not.

Me filter is a cheap ebay filter for now, its brand new. I also though this could be the porblem and tried taking it off altogether to see what would happen, and the same thing happened.

No intake passages left, they were all removed minus the main tube.

That voltage thing sounds look a good idea, im going to look into it and hopefully give it a try today.

thanks alot,
Dave

rx_prez

And just so you know its not only from idle. If i hold the throttle at 2k rpm or any rpm then give it gas the same problem occurs. Although it doesnt tend to be quite as bad as when I do it from idle.

ROTRY PWR

iTrader: (13)

3 issues:

1. Injector resistors possibly blown, your car will run but with the symtoms you describe.

2. Mazda decided to go from low to high impedance injectors somewhere during production of the 88 models so earlier cars have low`s and later ones have high`s. Make sure ou have the correct ones for your car and they didnt mixed up during the R+R.

3. With our cars close to (FC) 20+ yrs the wiring harness is pretty brittle from your R+R their might be some issues with the harness. I would thoroughly check each indivual injector wire and connector to make sure they are all OK. Repair or replace anything that looks faulty.

Your problem is with either injector/wires or resistor pack.

Amkard

rx_prez

I have the low impedance version without the resistor pack in the car, so that rules that out. also the injectors i got from ebay were the same (low impedance) and he had said they were from and 88 also (i checked anyways). I was acctualy reading about this this morning on old posts and decided to go double check - no resistor pack.

I will try the wires thing, it was suspicious to me before.. my only qualm with that is that the ONLY time it does that is when it is given gas. i think if they wires were shady it would randomly happen at other time to no? either way i will try this, the problem has to go, and its VERY annoying. I want to drive.

thanks
Dave

rx_prez

Tried a few things. without taking the UIM off tested the secondaries. it read a 0.4 ohm resistance between the ecu and the injector on both, is this normal? they both showed 12 volts when key was turned to on (acctually all 4 did at the ecu). at idle they read a obout the same but the secondaries read a 11.4 volts at the injectors. im guessing that that 0.4 ohms of resistance may be causing some problems. The secondary injectors showed the voltage to be decreasing when revved esp above 3k when measrued at the injector. i measured the bottom ones at the ecu, and it seemed that the voltage remainded the same when i revved the engine. In fact between 1k and 4k it only lowered 0.20 volts on both primary injectors at the ecu.

im starting to think my harness is just junk since its so old, i was intending on going stand alone and am not sure if its even worth the time trying to fix if i am going to do that. Asssuming of course its the harness thats junk.

would you recommend runnign new wires to the injectors? in the wiring diagram there is some kind of connector where all the injectors ground so i guess i would have to run the wires through there too. that made me remeber. i tried putting a direct ground to one of the injectors thinking that maybe it was a problem and since they all ground at the same point maybe it would help. the wire just got extremely hot and would have metled if i didnt take the wire off. should there be that much current runnign through them?