Iv got a crx with a d15b vtec swap and from 0bd-0 to 0bd-1 conversion harness in it, other then that its stock. It's been having a weird fuel problem, was wondering if anyone else has experienced this. It will start up and drive fine no problems there, when you get on the highway and get up to about 65- 70 and have a part throttle acceleration it starts to lean out and begins to miss fire very badly until i slam it WOT until it stutters out of miss firing . I hooked up a wide band to make sure it was a fuel problem and when i start the car everything looks normal but as soon as i start driving and i get up to 65- 70 its LEANS OUT TO 20:1 . But here is the really weird part if i keep driving it for another couple of minutes or so the problem just disappears. The air fuel goes back to like 14:1- 15:1. Im wondering if the person that had this car before me has something weird with the wiring harness? Maybe the fuel pumps going bad or injectors? Its got to be something electrical. Please let me know what you guys think, thanks alot

 

WHat codes are you throwing?

 

I have one code and it only pops up only in a once great while. 17 the vss, it hasn't had a speedo cable since i bought the car.

 

You need to do a fuel pump flow test This will tell you if your pump is bad or if the lines are restricted that will deffinently cause lean conditions.

 

I hooked a fuel pressure regulator up to it today and when i had it set at 40psi it had the same problem. When i set the pressure to 60psi it went away but it runs was to rich once what ever the problem is goes away.

 

Fluel flow test not PSI. You need to disconect your fuel return line and stick it into a empty bottle.Then jumper your fuelpump power wires in the mainrelay( exactly the same way you jumper the ecu to test codes but in the main relay) then turn the key on and count to 10 then turn the key off. By doing this you will run your fuel pump with out the engine running and it will tell you how things are flowing. As you can see from the pictures you should have atleast 7.8 ounces in 10 seconds or less. I had a simalar problem on my friends crx it turned out to be the fuel feed line to the rail. The banjo fitting and nut were mixed up and not letting enouf fuel in.

 

When it was doing it in your friends car would it just go away and would not come back until you shut the car off and got up to 70 again. Ill test the flow out thanks alot for that diagram. I really hope its not something electrical

 

Im only asking because im really low on money lately and i can't really afford to buy something i don't need. Thats why im trying to pin point it. thanks for your help so far.

 

any word on the progress of the problem verry interested in what it could be seeing im having a similar problem!