1jz cutting out, going lean, wont rev past 2500rpm

[kamikazemkiii]

I cant seem to get my 1jz to rev past about 2500 rpm before it cuts out and goes lean, i have no idea what to check codes. They guy who did the swap didnt wire in diagnostics... I have already replaced the fuel pump. Tested new fuel pump and the fuel system, holds pressure so im not sure what to check now. Could my afpr be giving me this problem? I have noticed that when i wiggle the soft line thats supplies the fuel that the afpr will either loose or gain about 5lbs of fuel pressure. Is that normal or could that be giving me my problem?

I am using the same map that the car has running on. Also tried adding fuel and that hasn't solved the problem either.

Mods:
61mm turbo
550cc injectors
TT fuel pump
Aeromotive afpr
Stinger ems


Thanks, Marcus

 

[kamikazemkiii]

bump

 

[Satan]

There have been several different fixes that have worked for similar symptoms. TRD87T went thru all the usual troubleshooting/changes and finally fixed by replacing a clogged/restricted fuel line (maybe the dampner too).

Others have replaced capacitors in the ECU, coolant temp sensor, and other misc sensors. Search for "2500 rpm issue" here and on Supraforums. Good luck!

 

[kamikazemkiii]

So their has been a similar issue?

Will check it out, thanks!

---------- Post added at 05:38 PM ---------- Previous post was at 05:33 PM ----------

I cant even drive the car ill be in 4th gear going 25mph and still goes 18+ afr. Any lower gear the car will just choke out and buck.

 

[kamikazemkiii]

Ill try messing with the TPS and with replace the fuel filter, any other ideas?

 

[Vrank!!!]

Ill try messing with the TPS and with replace the fuel filter, any other ideas?

Try the tps... I'm stupid and put it on the wrong way one time ( on the inside, I had the prong things on the opposite side of where they shoulda been) and it did exactly this, wouldn't go much over 2 grand and then fall flat on it's face.

 

[kamikazemkiii]

I dont see how, i havent messed with the tps???

 

[RacerXJ220]

A code is not going to show up with a Stinger EMS. Unless you put a stock ECU in, but then you'd need to use a JZ MAP sensor, but not with the 550's you have unless..... whatever....

There are just way too many things it could be.

 

[kamikazemkiii]

A code is not going to show up with a Stinger EMS. Unless you put a stock ECU in, but then you'd need to use a JZ MAP sensor, but not with the 550's you have unless..... whatever....

There are just way too many things it could be.

Yes thats the other thing, Im trying to narrow down the things it could be

 

[RacerXJ220]

When did the problem start?

Has the car worked fine previously with the mods?

Does it happen during free rev or driving?

How do you know it's lean? Wideband?

Make sure the vacuum hose going to the stinger is hooked up.

 

[kamikazemkiii]

Everything has been fine till about a month ago the problem started when a fuse blew leaving the car driveable but i wouldnt boost because it would get too lean and start cutting out. Then i installed a new fp and the same deal so i thought maybe the new fp was bad, so i bought a new TT fuel pump. I was cleaning up the engine bay and took the vaccume hose off the stinger and cut all the access off. When i went to drive the car after this problem started. Cannot free rev the car about 2500 rpm without it going lean via my aem wideband, driving is even worse with very little throttle applied the car is still very lean and cuts out.

 

[kamikazemkiii]

bump

 

[RacerXJ220]

Does it also run rougher than usual at idle or when you first start it up cold?

 

[kamikazemkiii]

Yes it fluctuates from about 800-400 and it has pretty good afr's till u rev on it any. I hooked up my laptop to it and the stinger only read at most 8psi vaccume. I did a compression test and every cylinder came out in the 120 range. Could a vaccume leak cause the car to act like this? or could it be a collapsed fuel line or clogged fuel filter?

Once throttle is applied and the AFPR looses a lot of psi, its in the 30 then usually dips to about 15psi then it starts backfiring and cutting out.

 

[kamikazemkiii]

bump

 

[Jostar]

Everything has been fine till about a month ago the problem started when a fuse blew leaving the car driveable but i wouldnt boost because it would get too lean and start cutting out. Then i installed a new fp and the same deal so i thought maybe the new fp was bad, so i bought a new TT fuel pump. I was cleaning up the engine bay and took the vaccume hose off the stinger and cut all the access off. When i went to drive the car after this problem started. Cannot free rev the car about 2500 rpm without it going lean via my aem wideband, driving is even worse with very little throttle applied the car is still very lean and cuts out.

Did you connect the vaccum hose back to the stinger??

 

[kamikazemkiii]

Yes

 

[86_sports_1jz]

damn sounds like we both have the same problem... i never figured mine out either... does your run really rough and idle really low? mine runs super rich, in the 9 afr at idel then runs super lean 16+ above 3k rpms i'm thinking about replacing my 550s for the hell of it cuz that was the last thing i put in

 

[oldsking]

Check your fueling system bro that car isn't getting enough fuel and even when we tuned the injectors it's the same, still super lean

 

[kamikazemkiii]

I unpluged the coilpack connectors while the car was running and nothing changed on #1 and 2, so Im going to swap coils with another cylinder and see if its the same thing. If it does the coils are bad but if it dosent, its probably some wires that are messed up. That should explain low vacuum and the reason why its running like shit right?

I am going to clean the fuel system too, it might be running rich actually because the way the coils are. No spark to ignite the fuel and its just raw fuel and the wide band cant read it