Fuel Pump Destroying my MPG?

[BlackMount]

FYI I did some searching on this and it really didn't help me

I have 1990 Laser RS Turbo

engine Mods

5 Speed
MBC set @ 15 PSI
14B Turbo
Tubular Manifold
Aftermarket Fuel Pump
Oil Cooler
NGK plugs
Stock Injectors

bought the car about a month ago, and just recently I have been getting REALLY bad gas mileage. my last tank of gas lasted me 170miles (and I had been babying the hell out of the thing)
The first time I filled the car up completely when i bought it I got about 240 miles on a single tank (and I did alot of ZOOM ZOOM that week too including more then 1 Top Speed Run 139 so far )

Part of it is because I have a bad ECU, but I've HAD a bad ECU and i had decent MPG before.

just today I was doing some errands, and I hopped on the interstate for a good 2 miles, and it drained 1\2 a quarter of my tank. In town if I baby it, i get pretty decent MPG it seems.

Is it because of my Fuel Pump? I don't know what pump exactly it is, all I know is it probably the typical Walbro 190LPH or 255LPH. If that's my Fuel Problem I will Happily trade for a Stock Turbo Fuel Pump straight up, no strings attached. I don't need this fuel pump because my car is a DD, and I don't do serious enough racing, or push enough boost I think to need it.

P.S (My Fuel Pump has not had the "Re-Wire" could this be part of my problem?)

HELP

 

[BlackMount]

I'm pretty Religious on maintenance, and all maintenance is up to date.

I just need my ECU fixed, problem is. I don't have money to do anything at all except get my self back and forth to work right now. The Car doesn't miss at High RPM's AT ALL its only at low, and low mid RPM's.

Paying Attention to my Aftermarket Boost Gauge my car only misses when my boost gauge is reading less then 15 lbs, but more then 0 (usually about 3-10 lbs is when it misses the most). If I hit a full 15 lbs by the time I hit 3K I'm gone and the car will pull EXTREMELY hard. usually about 3\4 of WOT will get me to 15 lbs in time, any more and the motor bogs and cuts out, any less and the boost wont build fast enough.

EDIT: I can still Brake Boost with a good launch with out any problems at all. (more like clutch boosting but same concept and works almost the same way, except it's hard on my clutch but i got a nice stage 2 layin around I'm gonna be installing this spring )

 

[KazooGS-T]

So did you check for a boost leak?

 

[BlackMount]

So did you check for a boost leak?

Yes, All my Turbo Plumbing Hoses, Coolant\Water Hoses, Vacuum Lines are BRAND New.

No boost\coolant\air\oil\exhaust leaks

 

[ramsack]

well i got a fuel pressure gauge, and with the vacuum line unplugged i read 60 psi, and 42 psi plugged in! so i swapped in another fpr and it's at 44 psi for now. just waiting for this stock regulator to get ruined and work its way back up until i can get an afpr. the car boosts a little better now, but there is room for improvement.

 

[LiquidX]

Yes, All my Turbo Plumbing Hoses, Coolant\Water Hoses, Vacuum Lines are BRAND New.

No boost\coolant\air\oil\exhaust leaks

I don't know if you actually performed a boost leak for you to answer "yes" or you are just saying that you don't have leaks because you have new lines.

Remember, anytime you change, alter, adjust couplers you should ALWAYS perform a boost leak test to be sure that the seals you made are solid. Zip tie all vacuum lines at the nipples too. Many places can leak and I actually had a boost leak in my AFPR at the screw adjustment. So be sure to get that done since you changed your parts.

For the ECU, you need to get that fixed so try to find a ride to work/school for a few days while it's sent out and repaired otherwise find a temp. replacement from someone.

 

[BlackMount]

I don't know if you actually performed a boost leak for you to answer "yes" or you are just saying that you don't have leaks because you have new lines.

Remember, anytime you change, alter, adjust couplers you should ALWAYS perform a boost leak test to be sure that the seals you made are solid. Zip tie all vacuum lines at the nipples too. Many places can leak and I actually had a boost leak in my AFPR at the screw adjustment. So be sure to get that done since you changed your parts.

For the ECU, you need to get that fixed so try to find a ride to work/school for a few days while it's sent out and repaired otherwise find a temp. replacement from someone.

I wouldn't have bought new Turbo Plumbing if I didn't have a Boost leak. Why replace something that's working properly?

and thanks for the help bout the ECU, but your just echoing whats already been said 40 times on this thread, and its something I already know.

 

[LiquidX]

I wouldn't have bought new Turbo Plumbing if I didn't have a Boost leak. Why replace something that's working properly?

and thanks for the help bout the ECU, but your just echoing whats already been said 40 times on this thread, and its something I already know.

What I was saying is if you replaced the parts or even took off a coupler you still want to perform a new test to ensure that nothing is leaking anymore.

 

[ramsack]

yeah i agree. tests are free and with something like carpentry or whatnot, you measure twice and cut once.

 

[dsmfa9nutter]

You want to solve your problems? Get an afpr and a new ecu (or fix the one you have). That's it, all that's to it.