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whitechocolatelove

240z turbo swap NEED HELP!!!!

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so ive had this thing finished for some time now but i cant pinpoint why its running weird. if you stomp on the pedal to rev it, it will just start to choke and sputter. it will pull hard up to about 4k but then it cuts out. my a/f gauge says its running really lean. the injectors appear to spray good, the fuel pump puts out 30 psi, the green light on the ecu comes on when the key is one and ive replaced the 02 sensor and the tps. does anybody have any advice?? its desperately needed and i dont have anything else to drive!!! lol

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I just read about the same problem a few days ago. There are a few posts about this, do a search on L28et swap/turbo swap and you'll find tons of info on it.

 

Some things i recall from past searches about the car running lean was because the afm was placed upside down. Try putting the afm the same way it was mounted in the ZX on the side. Here's a link about it. Hope it solves the problem somewhat.

 

http://forums.hybridz.org/showthread.php?t=103142&highlight=afm+upside

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ok so i replaced the fuel filter again, ran some injector cleaner, checked the timing, checked the afm and checked for vacuum leaks and i found nothing. the only thing i noticed is that the fuel pressure at idle is about 38psi and when i open the throttle it actually drops. i tried using another one i have and nothin happened. the last thing i can think of is maybe the fuel pump. and i dont know if this could cause it but i have the 240 tach still hooked up even though its the wrong type. oh and i have the hot wire from the 240 harness hooked to the + post on the coil. could this outside power source confuse the computer?

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in the thread that shows how to do the alternator jumper the harness theyre using has different wires so ive gotta find out which is which and what to switch. haha that rhymed. anyhow i realized that im using the stock 240z return line! oops! that would cause excessive pressure to be held back and increase my fuel pressure. and ive drove it more and now know its running extremly rich with a fp average of about 8 psi over normal! i pulled the plugs and sure enough black soot. turns out the gauge is reading lean because it is running so rich.

so im gonna head out and buy some fuel line and see if that fixes the problem.

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well i didnt check the volume today. i guess thats kind of manadatory in determining whether or not im getting the right amount of fuel. at idle im at about 36 psi and under load its about 40-42. i got an intake backfire a couple of times so i went to adjust the timing and it was at 8 degrees! so i adjusted the tvs and then adjusted my timing but it wouldnt budge from 24 degrees. took it for a spin and the only difference is that is pops and backfires more. im thinking the afm is messed up.

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8* is about right at idle. Total timing is more important. If it's popping through the intake it's lean unless you've messed with the cam or dist. Are you sure it's 40-42 psi under load. I'm mean WOT up through the revs not just pulling the vacuum source on the FPR.

 

I just realized this was a turbo swap. Does this happen only when going a little into boost? Are you using turbo injectors? Is this a factory turbo efi setup?

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yeah its 40-42 at wot under load and doesnt change when the engine cuts out. it does it sometimes while taking off and starts to around maybe 2500 and gets real bad by 4k. it seems to do that no matter what the boost level is. i bought injectors from a member on here and i regret that i did because the pintle caps (and they were large brown caps like the turbo injectors and the tips were about the same size as the caps.) were cracked and they were covered in dirt. i didnt have them flow tested but the spray pattern looked pretty good. and yes this is a factory efi setup.

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i know i should have done that but the only reason why i havent flow tested the injectors yet is because im running really rich. but i went out and checked my afm boots again and sure enough the one between the turbo and afm was loose! :bonk: started her up and there was a pretty big difference but i saw that the number 5 plug was sparkin on the outside! i replaced the wire and nothing happened. checked under the dizzy cap, and the electrodes (i guess youd call em) werent looking too great. so i think before i have the injectors tested im going to do a full tune up and see where that gets me.

and yes i know i should have in the first place.

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i know i should have done that but the only reason why i havent flow tested the injectors yet is because im running really rich. but i went out and checked my afm boots again and sure enough the one between the turbo and afm was loose! :bonk: started her up and there was a pretty big difference but i saw that the number 5 plug was sparkin on the outside! i replaced the wire and nothing happened. checked under the dizzy cap, and the electrodes (i guess youd call em) werent looking too great. so i think before i have the injectors tested im going to do a full tune up and see where that gets me.

and yes i know i should have in the first place.

 

 

Why do you think it's rich? What's the plug gap? I'm assuming it's stock boost. I would keep it in the .025-.028" range to be safe.

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well ive tried replacing everything i could. literally! and it seemed to be the injectors that fixed it for a little bit and then it leaned out again (both sets of injectors that ive installed so far had the same results). someboday on zcar told me its probably varnish in my gas tank causing the problem since it can make it through the filters and is the reason i didnt have a problem with carbs except having to clean the float bowls all the tim! which makes sense because i tried some of the stp injector cleaner and it didnt cure the problem but it sure helped! so i bought a gallon of acetone and im going to drop the tank, throw in some marbles and the acetone and clean away!

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