1jz cutting out, going lean, blowing fuses, Help?

[kamikazemkiii]

Alright guys i ask for help again, i'm not sure whats my problem this time

Well my problem started out last Friday afternoon, i was on the way home and the car shit off. I tried restarting it but it wasn't getting any fuel (also didn't hear the fuel pump kicking on). I call a ride, get picked up and come back. First thing i check is the fuse's. Find out the one is burnt slam out, so i replace it and i'm on my way. Well later on that day i'm driving once again and it blows out. This time i know whats wrong so i jump to it, this time with a 30amp fuse. Held up for awhile so i figured everything is good. Then it blowed so i talked with someone and they said more than likely it was the fuel pump getting old and just requiring more power than usual. So i replace the fuel pump and all that work for nothing it still kicked out the 15amp fuse i put in after replacing the pump. So i took it to my other friends house and we checked the relay and bolted it down, haven't had a problem since with the fuses so maybe it had been grounding out on the chassis and popping fuse's.

Heres the real problem, the car for some reason wont get into boost, when i say that i mean that when i attempt to make boost the wide band goes very lean and i have to back out. I'm not sure if its actually going lean or the gas just isn't being burned which the sensor wont read. When i do make a few psi it feels like its cutting out then the wide band starts leaning out. I'm not sure if its blowing the spark out but I've already re-gapped, installed 2 new pairs of plugs, tuned some, and still not sure whats wrong. I see black smoke and smell gas but i don't dare boost with scary AFR's. I really don't know what else to check, I'm still trying to learn more on the 1j's but not sure on this one. Maybe someone may have experienced this before or can offer some advice?

Not sure if its just a Coincidence or not, but the problem started to occur after i have the fuse issue.

 

[92TealSupra]

I wonder if your ECU blew a cap..

 

[staticpage]

I had a problem just like it. It took me a year to track down and it sounds silly. A friend had same problem after swap, and I think many posted problems are linked to it. I an article about earthing/grounding a month ago and talked to a shop that does a lot of swaps.
I installed a earthing/grounding kit and bingo all my cut out, stalls, hard starting, power surging, light dimming went away.
it's cheep to fix, easy to check just add a 4-8 gauge wire to the head mine was worn out and frayed in the sheath.

 

[f00g00]

Check the connection on the ecu that has the wires for the cps's, I was popping a code 13 after I replaced my caps in the ecu and I had a slight connection problem probably caused by reading from the plug to the cps's and bending the pins on the plug enough to have a bad connection.

 

[kamikazemkiii]

I forgot to mention that i the car drives great under vaccume, If it helps the mods are stinger ems, 550's, t61, walbro, afpr

 

[kamikazemkiii]

bump guys

 

[hvyman]

Never replace a fuse with a higher amp rating than whats supposed to be there or you will melt wires.

You have a wiring issue. Get a wiring diagram and go over all the wires in the circuit that is related to that fuse.

 

[suprahero]

When you say it's going lean, how lean are we talking and at what psi? It won't hurt you to go lean at two or three psi, but it should start going richer. Are you talking like 16's @ five to six psi or are you talking higher bost than that?

Have you switched your wideband with a friend to make sure it's not that? When I went to Texas last year, my wideband would never read richer than 13.9 for some reason. It was hard to race and stay in it while looking at that, but I stopped by a dyno in Louisiana and they verified that my car was running great......my wideband had just shot it's wad.

 

[kamikazemkiii]

When it starts going lean it doesn't richen up, they get about 18,19, and 20 after the first few psi. Just me thinking but i believe the signal isn't being sent to the fuel pump for when it starts getting into boost? possibility?

I cant even hit waste gate pressure (14psi) because i have to get out. I'm currently running 2 wide bands and both read very lean 18, 19, 20's before i get flamed, I don't boost.

Also feels like its studdering and i've re-gapped plugs maybe my coils ?

 

[suprahero]

It would be nice if you could see if the fuel pressure regulator was working. Is there a good vacuum source hooked up to it.? It just seems like it has to be in the fuel somewhere.

 

[kamikazemkiii]

Yes, it directly into the intake manifold.

 

[JPsToyota]

You're stuttering is probably because of your current issue. Don't go changing everything trying to solve this stuttering when it is directly related to your fuel issue, fix the fuel issue first.

Your fuse blowing sounds like a short to ground somewhere in your wiring. I had the same thing happen on a different fuse (AM2), turns out the harness loom was getting rubbed and would short one wire randomly if it moved in just the right position.

 

[suprahero]

Have you changed anything at all recently? Was it running perfectly and then it just started this? It just seems like it has to be in your tune or in the fuel pressure regulator.

Can you send me a link to your fuel maps to look at?

 

[kamikazemkiii]

Its was running great then i was on the way home one day and the car dies out, i get a ride home and come back. Turn the key to the power position and i couldnt hear the fuel pump. so i checked fuses and the efi fuse was burnt out a new 15 in and if blew off the bat. so i put a 30 to hold untill i got home. Later that day the 30 blew. I dont know what caused this, but it was all of a sudden and since i have had the boost problem. I just talked to one of my buddies and he believe's its the fuel pump even though its brand new. The car runs great but goes lean in boost. Their is no black smoke on the bumper with leads me to believe that the wide band is right.

 

[suprahero]

I don't know why your fuses blew. I'm guessing your problem has something to do with that. Are your fuel compensation maps all good? That couldnt' be the reason your car is running very lean could it? Has the weather changed in the last few days that would change the tune?

 

[kamikazemkiii]

The weather has been getting warmer accually so i dont think that has to do with it. Yes, my maps havent been changed so i dont think it has something to do with the stinger. Im going to check the wiring, then find a way to see whats happening to the fuel pressure when im supposed to be getting in boost

 

[suprahero]

any new news?

 

[kamikazemkiii]

Well i pulled the tank down last night, and replaced all the hoses and made sure everything is good and fresh. Tried to drive regularly and it went lean just, crimped the return hose and it took about 5 seconds to build fuel pressure when it should instantly. So i believe its the pump, ive got a new mk4 pump on the way. Pretty soon im going to redo the wiring once i find a diagram of the fuel pump wiring.