1JZ Running Issues, Bad MAP???

[1JayMK3]

I was sitting at a light and it stalled, no big deal.. Started it up and was fine. Got onto the highway and got into boost and all was good, turned off and while turning a corner it sputtered a bit, wideband at this point reading 10.0.

I shut it down, fire it back up and still brutal rich, pretty much rolling coal out the rear. Got it home and checked around, thinking it might be a MAP Sensor causing the issue, the car with the prior owner went through one MAP Sensor, he replaced it with this current one off of Ebay. It sounds like it has a 2 step if I try and give it any gas at idle, stalling out, running pig rich (10.0's) and tons of fuel burning.


Have read quite a bit and it usually comes back to leaking capacitors in the ecu OR bad Map's. The prior owner of this Supra had the exact same issue, 100% and it resulted in a bad MAP, causing it to be extremely rich, lean out under normal driving, scattering idle and stalling out. Exactly what it does now.



Sorry for the long explanation, just trying to cover all ground in one message, hope you're all able to give me a hand,

Thanks!

 

[Turbo Habanero]

A bad boost leak caused me to have this issue also.

Do you have a afpr ?

And yes a map can cause this.

2j map sensor will work plug and play

 

[mkiiichip]

Try testing your map sensor. There is some good info here on page 5.
http://www.autoshop101.com/forms/h35.pdf

 

[1JayMK3]

Try testing your map sensor. There is some good info here on page 5.
http://www.autoshop101.com/forms/h35.pdf

Thanks very much, will read up on it!

 

[1JayMK3]

A bad boost leak caused me to have this issue also.

Do you have a afpr ?

And yes a map can cause this.

2j map sensor will work plug and play

First thing I looked for was boost leaks, couldn't find a thing... But the vacuum was still good...I'll take another good hard look.

I don't have my AFPR on the car yet.

I'll have to order a MAP for the car as I live in the middle of no where, no one to even simply try an borrow from to see if that is the issue which sucks!

Thanks for the help though!

 

[Poodles]

Not hard to check the MAP sensor if you have the necessary tools to check it.

Checking the ECU is pretty easy as most of the time the caps will be visually bulging when they're bad (an ESR meter is the best way, but visual inspection is usually enough)

 

[1JayMK3]

I'll try and check that MAP today! A friend will be bringing over his voltmeter after for me to use. I was out checking it again for leaks and not a single thing, went through all my hard pipes and all are good and tight.

I unplugged the MAP and ran the car and it runs the exact same, not sure though if it goes into a fault/dumby mode though when unplugged causing it to remain running the same?

I have the computer out as well and will be inspecting the caps today to check for bulging/leakage.

 

[f00g00]

Faulty PCV valve? Mine would have intermittent white smoke and run rich like yours at 10 AFR's and would clear if I rapped on the throttle alot. I tried the TPS and an ECU, same issue, finally changed the PCV valve and fixed both problems.

 

[IBoughtASupra]

A boost leak will not make a JZ idle rich.

I vote MAP as that determines the load but check the caps though. What source are you using for the MAP sensor? Any filter?