Fuel System Advice??

[jeepzj94]

I did a lot of searching and reading but can't seem to find one thread that puts all my questions together with a defenitive answer. My setup is as follow: 94 gs converted to turbo. 60 trim turbo, 550cc injectors, stock n/t FPR, 255 fuel pump, turbo ecu, turbo MAF. My car runs super rich and really isn't fast at all. I know that the majority of the problem is with the fuel system. My question is, until I get a budget together to get a wideband, and sometype of tuning device, SAFC, dsmlink etc.....would I be better off just finding a set of stock turbo injectors to put in instead of the 550's? Would that lean my car out any and make it run smoother and faster. At idle, the car very noticeably misses, I'm guessing because of the overrun stock FPR. And won't pull past about 5k, just starts hesitating, sputtering and popping. I don't believe its fuel cut, I think its just drowning in fuel. Or should I try to find a good deal on an SAFC along with an AFPR and keep the 550's in. Also, I've read a few things on disconnecting the vacuum line on the stock FPR?? Should I be running it this way?? O2 sensor is in good working order, and the plugs and wires are brand new gapped at .028. No boost leaks. Also, only running 9lbs of boost since i'm still on stock n/t internals. Shoot me some advice!!

 

[LocknessMonster]

i would try and get a good deal on an safc and wideband. Between the two of those u can get the car running with a better afr.

 

[nlzn]

The car is going to slug without any type of fuel control. You can go back to the stocker injectors and it should help some, but really to fix the problem you are going to have to shell some cash. (be careful, not enough fuel is going to cost you way more than too much with those high compression pistons)
Wideband is optional. Im assuming your car is running waaaay too rich, you could benefit from a narrowband AFR reading and get it to run a ton better. But, wideband tuning is where it is, tuning at 12.2 and 12.5 can be the difference in 20% power on some motors.
Best advice like stated above, get a cheap safc and some type of FPR would be highly helpful and that setup will come alive

 

[Aphix]

You need a AFPR. Especially if you're running a 255lph with the stock nt FPR.

 

[KelTsi90]

You can get an Maf-T or Safc to compensate those injectors. And yes you will need a fpr. Always use 93oct gas. I'm using the Maf-t with 550's, I've set the fuel pressure at 42psi and lean out a little on the Maft and it pulls nice...

 

[Brutus]

I did a lot of searching and reading At idle, the car very noticeably misses, I'm guessing because of the overrun stock FPR. And won't pull past about 5k, just starts hesitating, sputtering and popping. I don't believe its fuel cut, I think its just drowning in fuel.

You answered you own question. You are overrunning your fuel pressure regulator. The stock regulator cant handle near the pressure that a 255 pump (which you dont need for 550's and 9psi) puts out. Get a real one with a gauge and set it correctly. Another fix would be to put a stock fuel pump back in the car.

 

[jeepzj94]

You answered you own question. You are overrunning your fuel pressure regulator. The stock regulator cant handle near the pressure that a 255 pump (which you dont need for 550's and 9psi) puts out. Get a real one with a gauge and set it correctly. Another fix would be to put a stock fuel pump back in the car.

Would the stock fuel pump still be able to adequately supply the 550's with 9lbs of boost and not cause me to run lean? If so, then that is what I'll do just until I get enough overtime in to go on a fuel system shopping spree!

 

[spyderturbo007]

You need to pick up a SAFC, DSMLink, etc, or pull those injectors and replace them with stock 450's. You're running 18% richer than stock right now, since the ECU can't compensate for the larger injectors.

I'm suprised you don't have a FT malfunction CEL right now.

Can you be a little more specific with regards to the parts you installed. For example, I'm assuming it's a 1g turbo ECU, but is it from an automatic or a manual? Also, the MAS you're running, is that from a 1g or a 2g? Those things do make a difference.

 

[jeepzj94]

Yes, the ECU is from a 1g with a manual tranny. Also, the mas is from the same car as the ECU, a 1g turbo. And no, I have no CEL on. The car is my daily driver, and I don't have a set of stock turbo injectors to put in it. But I do have the stock fuel pump I can swap back in. Would this be an ok fix until I can get the AFPR and SAFC?

 

[spyderturbo007]

You'll be overrunning the FPR with that pump, but your biggest problem is the injectors. You really, need something to compensate for the larger injectors or pick up a set of 450's until you can save the money for a SAFC or DSMLink.

 

[jeepzj94]

You'll be overrunning the FPR with that pump, but your biggest problem is the injectors. You really, need something to compensate for the larger injectors or pick up a set of 450's until you can save the money for a SAFC or DSMLink.

Is there a difference between the stock n/t and turbo fuel pumps?? And do you mean if I use a stock turbo fuel pump I will overrun the n/t FPR?? I think I'm just gonna park this thing and drive the gas hog jeep until I have the money to set it straight. But even with it running as rich as it is, it still gets better mileage than the jeep .

 

[spyderturbo007]

I have no idea about the N/T fuel pump. I have very limited knowledge when it comes to N/T's, well, actually no knowledge. But since you are running a turbo ECU and MAS, the way fuel metering works is exactly the same.

Do you know the flow rate of the N/T pump?

Basically, I was saying that the majority of your running rich problem is caused by the 550cc injectors and no compensation. The 255 pump is also causing problems, but not as much as the injectors. I think your idea to park the car is a good one, only because running really rich is also dangerous. Just make sure once you get everything straightened out, that you change the oil and replace the plug wires.

All you really need right now is a SAFC and an AFPR.

 

[jeepzj94]

No, I don't know the flow rate of the n/t fuel pump. I assume its probably the same pump that is in the turbo cars.

spyderturbo007: Thank you for all the input and advice....Definitely gonna park the car till I get the AFPR and SAFC. Don't want to get stranded cause I foul the plugs out and give myself a bigger headache then I already have. (Excessively rich exhaust fumes in the cabin are no good)