fuel problem

Discuss the RB20, RB25 and RB26 series engines.
herndiggle
Posts: 37
Joined: Mon Apr 26, 2010 7:40 pm
Car: 95 s14 rb25

Post

i know i have no post, but thats because i had to make a new account cause i cant remember my s***.

anyways having a problem with my rb25. it was running fine, but rich cause i got 850cc and no tune. (haha) well anyways i went to start it up cause i had to move it and it turned over and immediately bogged out. i know its getting wayyy to much fuel but why, since it was driving and idling fine 12 hours ago. i was doing some troubleshooting and i found a few things. the white wire on my z32 maf (if i remember right is the 5v return wire) is a little questionable. three wires out of about 7 of the wires that run to my o2 sensor are pinched but there is no reason they shouldn't be getting power. pulled the sheathe off of one and looked fine.

things that i noticed were that my air/fuel gauge with the key tunred to the on postion is resting about 14.7. after about 20 seconds it will claim to above 18.0 not sure exactly what it goes to cause it goes off the aem chart. lol. it i start the car before it goes off the chart it idles just fine, then about 10-20 seconds later it boggs out. still running, but at about 400 rpm and no gas can be applied without killing the motor. if i let it peak out and try and start it then it doesnt want too. trust me im no trying to f*** up my motor but starting it over and over and trying to rev it to make it work like some people i know. i was just trouble shooting. i get some nice black smoke when bogged (of course). i was thinking my FPR is f*** but not sure (stock btw). looking for some help. sorry for the lengthy post but wanted to make sure everything was covered


mods im running are

t3/t4
z32 maf
apex fic
q45 tb
greddy knock off manifold
850cc's


mott6904
Posts: 679
Joined: Tue Jan 30, 2007 2:50 pm
Car: rb20 big turbo big cams s13, 97 kouki, turbo audi a4,turbo busa

Post

if you are running a z32 maf and 850cc injectors on a stock tune that is your problem. The gauge is normal it is just heating up.

herndiggle
Posts: 37
Joined: Mon Apr 26, 2010 7:40 pm
Car: 95 s14 rb25

Post

well the point is with in a 12 hours period it started doing this. i could drive it all i want before this started happening. i dont drive it unless i have too and i plan on getting it tuned very soon. only thing is i live 3 hours from any tuning shop and they aren't open on the weekends so its not like i can just go anytime. i hate to trailer the car 3 hours to find out i can't get it tuned cause my fpr, o2 sensor, maf, fuel pump, or whatever is bad. i looking for something more specific then "get it tuned"

i know that already

User avatar
RustspecS13
Posts: 928
Joined: Sat Sep 08, 2007 5:30 pm
Car: '74 260z and '88 300zx turbo

Post

Your spark plugs are likely getting coated in raw gas, so the more its ran as is the less likely they are to keep firing.

Does your oil smell like gas?

~Alex

herndiggle
Posts: 37
Joined: Mon Apr 26, 2010 7:40 pm
Car: 95 s14 rb25

Post

well im sure i am coating the plugs with fuel but they are still firing (all 6). i have yet to check and see if the oil smells like fuel but i wouldnt doubt it. need to change it anyways. ran a compression check and for a cold check it runs good. im changing the FPR today so maybe that will help if not ill just have to find some time to get it tuned

mott6904
Posts: 679
Joined: Tue Jan 30, 2007 2:50 pm
Car: rb20 big turbo big cams s13, 97 kouki, turbo audi a4,turbo busa

Post

put stock injectors, maf, and new plugs in it and see if your problem is still there. If its not then get a tune.

herndiggle
Posts: 37
Joined: Mon Apr 26, 2010 7:40 pm
Car: 95 s14 rb25

Post

yep. gettin a tune


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