1jz over fueling

Johnsupra · 04-02-2011, 11:32 AM

my 1jz is over fueling realy bad it wont pass 3000rpm i have tried fuel pump,injectors,coil packs,map sensor,intercooler,ecu,and every sensor and unit that is in the engine bay . can anyone please help

Green7mgte · 04-02-2011, 01:30 PM

when you say over fueling do you mean running rich?
do you get backfires things like that?
First lets start by checking what codes you have.
off the top of my head.. Fuel pressure regulator?
TPS, MAF, ECT, and then O2. The O2 sensor is the last on this list

post back with codes. oh snap you said Ijz. bummer I've never owned one.
Perhaps someone else can chime in.

Johnsupra · 04-02-2011, 02:08 PM

Quote:

Originally Posted by Green7mgte

when you say over fueling do you mean running rich?
do you get backfires things like that?
First lets start by checking what codes you have.
off the top of my head.. Fuel pressure regulator?
TPS, MAF, ECT, and then O2. The O2 sensor is the last on this list

post back with codes. oh snap you said Ijz. bummer I've never owned one.
Perhaps someone else can chime in.

ya running rich and backfiring at not giving any codes everything is coming up ok

Green7mgte · 04-02-2011, 02:14 PM

hows your timing?

Travis89Turbo · 04-02-2011, 04:12 PM

Quote:

Originally Posted by Johnsupra

ya running rich and backfiring at not giving any codes everything is coming up ok

You probably have leaking capacitors in your ecu. I kno you said u tried other but 95% of 1j ecu have leaking capacitors I had to replace mine not even a week ago.

The good thing is that it is easy to do if u kno how to solder. And about $2 for parts. Here is a link.

http://www.toymods.org.au/forums/sho...placement-info

cre · 04-02-2011, 08:31 PM

Knock is another possibility.

Johnsupra · 04-02-2011, 10:36 PM

Quote:

Originally Posted by Travis89Turbo

You probably have leaking capacitors in your ecu. I kno you said u tried other but 95% of 1j ecu have leaking capacitors I had to replace mine not even a week ago.

The good thing is that it is easy to do if u kno how to solder. And about $2 for parts. Here is a link.

http://www.toymods.org.au/forums/sho...placement-info

i have tried a ecu i know is working perfect and its stil the same

Johnsupra · 04-02-2011, 10:39 PM

Quote:

Originally Posted by cre

Knock is another possibility.

tried that to is there any relays or units inside the car that can cause this

Travis89Turbo · 04-03-2011, 12:19 AM

Quote:

Originally Posted by Johnsupra

tried that to is there any relays or units inside the car that can cause this

No.

You could always get a piggy back system and an a/f gauge. The 1j runs rich from the factory.

A dirty airfilter can also cause it!

Check your spark plugs. gapped between .020 to .028 all 1j are really picky when it comes to spark plug gap. mine has to be set at .024 EXACTLY or it will putter.

cre · 04-03-2011, 01:53 AM

No, extra rich fuel and reduction in timing is a function of the ECU in the presence of ping and knock. If you have changed the octane of the fuel you're using and the climate hasn't changed significantly a ping could be bad news; If it's gotten hotter and/or drier and you aren't using a high octane fuel you may want to try it and see if performance improves.

How did you test the MAP sensor and the IAT sensor?

04-02-2011, 11:32 AM	#1
Johnsupra Stock Join Date: Nov 2006 Location: galway, ireland Posts: 9	1jz over fueling my 1jz is over fueling realy bad it wont pass 3000rpm i have tried fuel pump,injectors,coil packs,map sensor,intercooler,ecu,and every sensor and unit that is in the engine bay . can anyone please help

04-02-2011, 01:30 PM	#2
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	when you say over fueling do you mean running rich? do you get backfires things like that? First lets start by checking what codes you have. off the top of my head.. Fuel pressure regulator? TPS, MAF, ECT, and then O2. The O2 sensor is the last on this list post back with codes. oh snap you said Ijz. bummer I've never owned one. Perhaps someone else can chime in. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

04-02-2011, 02:14 PM	#4
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	hows your timing? __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

04-02-2011, 08:31 PM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Knock is another possibility. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

04-03-2011, 01:53 AM	#10
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	No, extra rich fuel and reduction in timing is a function of the ECU in the presence of ping and knock. If you have changed the octane of the fuel you're using and the climate hasn't changed significantly a ping could be bad news; If it's gotten hotter and/or drier and you aren't using a high octane fuel you may want to try it and see if performance improves. How did you test the MAP sensor and the IAT sensor? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->