1JZ rev problems - Toyota Nation Forum : Toyota Car and Truck Forums

Menace_121 · 07-25-2009, 01:26 AM

hey a buddy has brought me his 1jz 89 supra that is havin a reving problem, it wont go passed 3000 rpms he has an aftermarket ecu but unfortunatley i havent asked which kind yet, but hes sent the ecu in 3 times and gotten new ones and nothing has changed, now over time its gotten weaker, sine about a week ago its dropped to not wanting to rev over 1000, was wondering what possibly i should look at, i have worked on a 1jz before so i know what im lookin at and what not but i did it all myself and didnt on this so just wnna get insigh before i start testin stuff, i was thinkin possibly the TPS is wired wrong or getting a wrong lead, what u guys think, thanks

Menace_121 · 07-26-2009, 02:33 AM

well i went and looke at it today, guess it is running stock ECU but only 1 of the injectors were pulsing so hes tkin em down to get cleaned and rebuild and that should sole the fuel cut issue

Jeeves · 07-27-2009, 11:39 AM

Only 1 of 6 injectors were pulsing? The car would not run on one injector.

Fuel cut does not happen due to injectors. Fuel cut is a computer controlled mechanism. Is the car throwing any codes? The rev limits all sound like a dead MAF more than anything else. Try unplugging the MAF and see if your symptoms change.

Menace_121 · 08-31-2009, 12:44 PM

Quote:

Originally Posted by Jeeves

Only 1 of 6 injectors were pulsing? The car would not run on one injector.

Fuel cut does not happen due to injectors. Fuel cut is a computer controlled mechanism. Is the car throwing any codes? The rev limits all sound like a dead MAF more than anything else. Try unplugging the MAF and see if your symptoms change.

oh ya i know i was just menaing the fuel loss, and only 1 was pulseing strong, they were all pulseing but the other 5 was really weak, i had the same problem in my mr2 the just needed to be cleaned, havent heard back from dude yet, we'll see if that fixes it

Jeeves · 08-31-2009, 01:22 PM

Still shouldn't cause fuel cut. Fuel cut is entirely ECU/sensor related. Could cause it to run rough/lean/poorly though.

Menace_121 · 08-31-2009, 01:37 PM

Quote:

Originally Posted by Jeeves

Still shouldn't cause fuel cut. Fuel cut is entirely ECU/sensor related. Could cause it to run rough/lean/poorly though.

Ya i know, im meaning they arent feeding the cyl with sufficent fuel caus they are clogged, gunked up ect ect, was just refering to the cut as in a loss, the ecu i know manages this but since the inj are clogged and cant pulse the sufficent ammount of fuel, but like you said it was running pretty rough with 1 cyl only getting the proper fuel haha

ddouglas77 · 08-31-2009, 06:14 PM

Could very well be, also, a bad catalytic converter-I am disregaurding the "weak" injector pulse as that sounds to be BS. Check exhaust flow.

Menace_121 · 09-01-2009, 10:00 PM

Quote:

Originally Posted by ddouglas77

Could very well be, also, a bad catalytic converter-I am disregaurding the "weak" injector pulse as that sounds to be BS. Check exhaust flow.

sounds to be BS?? thats exactly wat the problem was on my 1j and my 3s its not a BS issue, if they dont pules theres no fuel, and the cats good btw

Jeeves · 09-02-2009, 03:15 PM

I will say that "Weak Pulse" isn't a good term. "Poor flow" or a "dirty injector" is a far better term.

Menace_121 · 09-02-2009, 08:59 PM

Quote:

Originally Posted by Jeeves

I will say that "Weak Pulse" isn't a good term. "Poor flow" or a "dirty injector" is a far better term.

haha ok my bad, physically the injector had a weak pulse by touch, but they are dirty and not getting sufficient flow, that should clear it up haha my bad