70 psi fuel at 15-16 psi,38 psi at idle?????

[turbo96max]

I have a small problem with my 86 grand national. The car was adjusted by Rick Harper, he adjuste the tps, iac motor, fuel pressure at idle when i took the car in for some oil leaks. Now , I had closed the boost controller to 10 psi before hadn since the car wasnt running right. He adjusted the tps bc it was not seeing full throttle before. I got the car back and it starte poping at 11 psi, so he told me to put up the boost that it was too rich after 3500 rpm the ecu steps up the fuel. So i did and it got cleaner and cleaner, but he told me that i should be able to run 17-18 psi on 93 pmp gas and the 93 chip . i have a huge front mount, a pt54, 3 inch downpipe, full exhaust, 42 lb re injectors, 3 inch intercooler pipes, new maf. the car now pops after 15 psi, and the fuel pressure is about 70 psi at 16-16 psi.He told me that was too much fuel pressure and that could be y its poping. But he has never seen a car raise psi like that, that maybe since i dont have the tanks canister hooked up, so the pressure maybe building in the tank??? any suggestions? can the coil be weak? will the car be too rich at 70 psi and 15-16 psi? i am running 14 psi now and i get 60 psi fuel and it runs ok. i think the car runs better at a little bit below full throttle.

 

[SMS]

Your fuel pressure shoulds follow the boost right up. Meaning if you have 38 psi at idle, you should have 54 at 16 pounds of boost. What chip are you running? Is it supposed to be set at 38 psi, line off, at idle? If you have a restriction in the return fuel line, it could cause the FP to go crazy too.

 

[turbo96max]

I have a redish orange street chip, im not sure who its from. it may be red armstrong. the thing is that its supposed to be 1:1 fuel pressure increase, but its acting like a fmu, and the pressure is climbing more tha 1:1 above 15 psi, like 1:3, do you think that i should replace the return line? can the canister not being connected make a difference, bc its supposed to release fumes and pressure out of the tank???? this has megoing nuts....

 

[SMS]

Don't think the cannister has much to do with it. I would examine the return line for any damage, and maybe disconnect it and blow air through it to see if it's clear. Can you try another fp regulator?

 

[turbo96max]

I am going to blow through the return line tomorow and post the results. If it had some restriction, what would it be? old rotten hose material maybe? maybe ill try putting the pressure at the bare minimum ,like 32 or something as long as the car doesnt turn off, and see how high it goes ?

 

[SMS]

If you're not sure who made the chip you have, are you at least sure it is burned for the injectors you are running? This has nothing to do with the fp problem, just another possible link to the poor performance.

 

[DavzGN]

Is the connection to the boost gauge leaking? A leak between the engine and the gauge would cause the guage to read low.

David

 

[cabech984]

Yeah, check your boost gauge connections/ line!! I thought a made a 110mph pass on only 12psi and a TE-44 turbo!! Fixed the leak and it was more like 20psi!!