[breezeflow]

had crazy cracks under my coilpacks, just replaced them with brand new denso coilpacks. The car is much much better, but when I hit ANY boost it will go full lean!

Stock 1jz non vvti, blitz air intake, blitz dual exhaust,
-aem wideband 30-4100
-ecu is mint, no leaks or bad caps, looks brand new!
-coilpack connector/clips are fine

 

[Jdmsup]

Fuel pressure or filter?

 

[breezeflow]

Im going to check the fuel filter tonight, not sure how to check fuel pressure though. Didn't know a bad fuel filter can make it breakup to the extent of any boost coming on

Fuel pressure or filter?

 

[Wreckless]

It's uncommon but if it's a factory original fuel pump, that could be failing or there could be a bunch of junk/dirt/whatever in the fuel tank. I've seen some nasty old fuel tanks that had a bunch of crud in them now that these cars are getting old.
You should replace the fuel filter first and see if the behavior continues, though. If replacing the filter cures the issue, definitely check the tank and pump to make sure it's clean.

 

[220]

Verify the map sensor part number is for a 1J, and chech the vacuum hoses.

How lean is it?

 

[breezeflow]

Will verify map sensor tomorow. Can I test it with much a multimeter? WOT will have it full lean - - - and obviously followed by misfire

Verify the map sensor part number is for a 1J, and chech the vacuum hoses.

How lean is it?

 

[breezeflow]

Update guys: it leans out full lean under WOT!!! To verify this I put the car in a high gear at low speed (2k in 4th or 5th) and went WOT, the Afr reading will immediately go to full lean - - -, even if I press the throttle fully for just half a second and let off really quickly, the Afr will be full lean. It could be the map but could it also be the tps? Any other input/possibilities much appreciated.

 

[breezeflow]

BTW I've done a compression test with 170 on 5 cylinders and 175 on one. The plugs are bkr7e gapped to .20 for diagnosing this misfire. The plugs are not dry or fouled they are normal

 

[220]

I'm just wondering if it's the right sensors, in the first place. Seems like the ECU doesn't know there's pressure in the manifold, and doesn't add more fuel.

 

[breezeflow]

89420-24040 - Map sensor (1JZ)

Its the right map sensor. Trying to look up how to test it

 

[breezeflow]

Guys, wondering if bad ignition can cause plugs to go bad?? My plugs have been in there with the badly cracked coils for a while before I got new ones recently

 

[220]

It wouldn't explain lean conditions. Does the guage behave normally, otherwise? It doesn't go full lean during idle or normal cruising does it?

 

[breezeflow]

Idle and cruise at 14.7, full lean when coasting

 

[breezeflow]

I have done a compression test at 170 on 5 cylinders and 175 on one

 

[breezeflow]

While running:

Unplugged IACV - no change
Unplugged TPS - change
Unplugged all 6 coilpacks connectors one by one - change on all 6
Unplugged MAP - car died immediately
Unplugged o2 - big change lots of bogging

Any input please

 

[220]

This is an interesting issue. I suspect something is wired backwards. It could be the ECU, but they usually run rich when they go bad.

 

[breezeflow]

This motor isn't a swap, its the factory motor and ecu (jzz30 Toyota soarer). The ecu wires couldn't be wired wrong, all original factory harness.

 

[220]

If you haven't followed up with Wreckless' suggestion, you should.

I've just been offering alternatives because I figured you tried it already.

 

[breezeflow]

It's uncommon but if it's a factory original fuel pump, that could be failing or there could be a bunch of junk/dirt/whatever in the fuel tank. I've seen some nasty old fuel tanks that had a bunch of crud in them now that these cars are getting old.
You should replace the fuel filter first and see if the behavior continues, though. If replacing the filter cures the issue, definitely check the tank and pump to make sure it's clean.

Wreckless, thank you for your knowledge! I pulled the fuel filter and out of it came dark brown liquid, there wasnt much big hard chunks or anything like that, but i think there may have been some tiny particles of some sort. I will be checking the fuel pump and fuel tank. I got a fuel filter from a local part store but it wasn't the right fit, made sure to note down the old filters part # before putting it back in as the new one didn't screw up to the 'out' side of the fuel line.

Knowing this now, is there anything else you can suggest?

 

[BoostFiend_MK3]

Check for volume of fuel. then check pressure. could be a filter.