Fuel pressure help

[1990turbo]

I just got my new motor running and am working all the bugs out. It is a dart 331 with 76mm turbo 55lb injectors. I turned the pressure up from 30 to 40. I am just wondering if its enough. There is no cats on it and i feel that the exhaust should smell a little richer of fuel. Any opinions?

 

[90stang5speed]

I would recommend that you get an Innovative Technologies LC1 wide band sensor and gauge for your air fuel ratio. Stock fuel pressure should have been around 38-40 psi already. Im going to be running a 76 mm turbo too and have 42 lb injectors but also use meth injection. I would think your injector size will be OK as long as you have upgraded the pump as well. Do you have a way to tune for the bigger injectors and a way to retard timing as the boost increases? If not you might want to look into that also. Im no expert but, it seems to me that without a way to tune, it would have to be overly rich at idle & cruise & have the timing manually retarded so that it would be safe under boost. Seems like that would make it run like crap unless you were at WOT. hope that helps. good luck with it.

 

[Rick 91GT]

You should have it set at 38-40psi with the vac disconnected, the EEC will trim the fuel to try to get it to a proper air fuel.

Do you have a chip or tuner on the car? Typically with a large injector I am pulling a lot of fuel out at idle to keep the plugs clean and not wash the cylinders out. If you don't I highly suugest having it tuned.

 

[1990turbo]

You should have it set at 38-40psi with the vac disconnected, the EEC will trim the fuel to try to get it to a proper air fuel.

Do you have a chip or tuner on the car? Typically with a large injector I am pulling a lot of fuel out at idle to keep the plugs clean and not wash the cylinders out. If you don't I highly suugest having it tuned.

AS far as getting it tuned i am having trouble finding someone to do it around Portland. It has an Excell Calmap fmu. The pump i think is 500lph. It does run a little crappy at idle and better when on the throttle. I do need to get an a/f gauge hopefully next week. At total timming its set at 28deg. and seems to have stopped pinging. Also its running a little cooler now. I saw temps up to 230 but was also stop and go traffic. I just spent $4000.00 on this short block and dont want to break it so any help I can get i will take.

 

[Rick 91GT]

AS far as getting it tuned i am having trouble finding someone to do it around Portland. It has an Excell Calmap fmu. The pump i think is 500lph. It does run a little crappy at idle and better when on the throttle. I do need to get an a/f gauge hopefully next week. At total timming its set at 28deg. and seems to have stopped pinging. Also its running a little cooler now. I saw temps up to 230 but was also stop and go traffic. I just spent $4000.00 on this short block and dont want to break it so any help I can get i will take.

230 is too high, you may be burning fuel in the exhaust...28 degrees timing under boost will be too high, youll be like 20-21 tops with 10psi or so (all depends on your specific combo)

Whats the complete combo?

Id get it to a tuner ASAP, sorry I don't know any dyno tuners up in that area.

 

[1990turbo]

230 is too high, you may be burning fuel in the exhaust...28 degrees timing under boost will be too high, youll be like 20-21 tops with 10psi or so (all depends on your specific combo)

Whats the complete combo?

Id get it to a tuner ASAP, sorry I don't know any dyno tuners up in that area.

Dart 331, f303 cam, 76mm Turbonetics, ported cobra intake, 55lb injectors, Accel Calmap, 500lph fuel pump, MSD 7AL2, Blaster coil, stock dist. Running premium fuel 9.0:1 comp. HKS electric boost control right now turned all the way down about 6psi i think. So you think i need to retard the timming more?

 

[90stang5speed]

If you dont have a tuner, it might be a good idea to take more timing out. On my 90 with an A9P EEC there is a WOT vs RPM timing and factory is only 24* Also, an area that I think you might have problems is at part throttle and building boost. I dont remember what the factory timing tables look like there but they are based on RPM vs load. Like Rick said, you might want to pull timing back to about 20*. With the SPOUT out I think that means your base timing would be set at like 6* I use the TWEECER RT & tune mine myself. there are other tuners out there that I hear are cheaper. You will want binary editor and EEC analyzer AKA (BE & EA) to go along with the tweecer RT or other tuner if you want to do it yourself. once you get the wide band in, I think a good AFR to shoot for is around 11.5 at WOT for boosted cars. Once you get a base tune you could the play with adding a little timing (1-2* at a time) or leaning out just a little. Snow performance says they recommend 12.5 AFR with water/meth injection.