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Topic: baaaaad gas mileage (Read 3235 times) previous topic - next topic

baaaaad gas mileage

So i am getting between 10-12mpg. I have stock injectors and stock fuel pressure and rarely get into boost. I dont have the EGR hooked up either. I drive up a steep hill everyday for school but i get to coast down it coming back. Ive never heard of a 4 banger getting this bad of gas mileage. My friends 800hp evo gets about that driving in town. Any suggestions?
1987 turbo coupe 5speed: Boport stage 3 head/2.5 cam , Precision stage 3 50trim .63 turbo, Tial 38mm wastegate, Jangus gutted/ported intake manifolds, 60mm tb, Jangus open dumptube, Jangus 3" elbow, Perrin boost controller,Esslinger adjustable cam pulley, Esslinger small crank pulley, stinger FMI, RFL BOV, Spec stage 3 clutch, B&M short throw, 140 speedo, Walbo 255lph, BBK fpr, 3G alternator, ARP studs.  Be faster... :poke:

baaaaad gas mileage

Reply #1 –
That sucks!  :(

I am going to go ahead and ask the obvious questions.

Have you given it a recent quality tune up?
Is there any other symptoms (any stutters, coughs, hiccups, overheating, etc)?
Are the rear brakes holding?
...and there was light!

baaaaad gas mileage

Reply #2 –
What are your a/f ratio's like and what tuner?
[SIGPIC][/SIGPIC]
1974 maverick lsx powered turbo car SOLD
1973 maverick Tijuana Taxi Tribute
1957 chevy LSX Turbo project (race car)
Owner of Joe Dirt Fabrication

baaaaad gas mileage

Reply #3 –
Codes.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

baaaaad gas mileage

Reply #4 –
I gave it a full tune up with the big turbo swap a month ago (besides a fuel filter).
sometimes when i take it out of gear, the RPMs fall to about 500.
My A/R gauge broke so im not sure. Im getting a new put in soon. No tuner yet.
I havent checked the code BUT its been throwing a code after about 20 minutes driving.( ive been super busy with college.)
So im guessing i should get the code checked out first thing huh? and go from there?
1987 turbo coupe 5speed: Boport stage 3 head/2.5 cam , Precision stage 3 50trim .63 turbo, Tial 38mm wastegate, Jangus gutted/ported intake manifolds, 60mm tb, Jangus open dumptube, Jangus 3" elbow, Perrin boost controller,Esslinger adjustable cam pulley, Esslinger small crank pulley, stinger FMI, RFL BOV, Spec stage 3 clutch, B&M short throw, 140 speedo, Walbo 255lph, BBK fpr, 3G alternator, ARP studs.  Be faster... :poke:

baaaaad gas mileage

Reply #5 –
Well, generally when you want something diagnosed, information relating directly to the cause is the first step. Even if you have to spend 5 minutes at it.

Your check engine light isn't a code, its a hard failure putting the car into limp mode so you can get home.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

baaaaad gas mileage

Reply #6 –
If it started with the big turbo, check to make sure VAM isn't being sucked open.

Also Temp Coolant Sensor and Air Charge Temp sensor can do that stuff.

Get codes :P
88 Turbocoupe: Coast High Performance 331 kit 28oz balance, Comp XE264HR14 cam, 58cc 185 afr heads, 1.7 roller rockers, Mass-Flo EFI (was POS to setup and their techline is a joke at best)
Full 1 5/8 primary equal length headers, 2 1/2 exhaust, Full manual reverse VB c4 and baked off clear coat "BECAUSE RACECAR"

baaaaad gas mileage

Reply #7 –
well when the check engine light is on, it drives just the same when its off. My coolant temp gauge shakes alot from time to time lately. Im taking my car into the shop tomorrow to get the codes. I was thinking my check engine light was on because my EGR isnt hooked up which is setting off my check engine.
everything is Motorcraft except the MSD coil for my tune up.
1987 turbo coupe 5speed: Boport stage 3 head/2.5 cam , Precision stage 3 50trim .63 turbo, Tial 38mm wastegate, Jangus gutted/ported intake manifolds, 60mm tb, Jangus open dumptube, Jangus 3" elbow, Perrin boost controller,Esslinger adjustable cam pulley, Esslinger small crank pulley, stinger FMI, RFL BOV, Spec stage 3 clutch, B&M short throw, 140 speedo, Walbo 255lph, BBK fpr, 3G alternator, ARP studs.  Be faster... :poke:

baaaaad gas mileage

Reply #8 –
Egr will not cause a check engine light. Let us know when we get codes.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

baaaaad gas mileage

Reply #9 –
That sucks, I thought my ranger was getting bad milage (19 - 20).
88 Cougar LS 5.0 .030 over, ported E7s with GT40 valves & trickflow springs, Proform roller rockers, HO cam, removed air silencer, K&N filter, smog pump delete, 2.25" dual flowmasters, Pacestter H-pipe & headers, HO computer, 65mm TB, Explorer intake, 19# injecters, 3.45s, rebuilt posi, and TCI shift kit.

baaaaad gas mileage

Reply #10 –
ALRIGHT i got a few codes!
14- erratic pin signal
23- TPS sensor
25- Knock sensor
34- EGR (took mine off)
41- lean always
65- over changing?

Im thinking the lean and knock is because my big turbo and colder air because of my front mount.
1987 turbo coupe 5speed: Boport stage 3 head/2.5 cam , Precision stage 3 50trim .63 turbo, Tial 38mm wastegate, Jangus gutted/ported intake manifolds, 60mm tb, Jangus open dumptube, Jangus 3" elbow, Perrin boost controller,Esslinger adjustable cam pulley, Esslinger small crank pulley, stinger FMI, RFL BOV, Spec stage 3 clutch, B&M short throw, 140 speedo, Walbo 255lph, BBK fpr, 3G alternator, ARP studs.  Be faster... :poke:

baaaaad gas mileage

Reply #11 –
14 Pip in the dist bad. This needs fixed. Could be tfi.
23 tps, obviously
25 knock sensor? don't know about these.
34 egr don't worry about this.
41 right side always lean. Generally means bad o2, or injector.
65 overdrive on off not cycled turing test. User error. This doesn't make sense to me. Do you have an electric overdrive onn off switch? If this code was 65 and act is below minimim, that would make a lot more sense.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

baaaaad gas mileage

Reply #12 –
Is the TFI the reason why i have erractic pin signal?
How can i tell if t TPS is bad?
Is the knock sensor ignition timing?
My o2 is brand new so im guessing injector. Would more dense air from the FMIC be doing this though also?
I do not have an over drive switch. Atleast not to my knowledge.
1987 turbo coupe 5speed: Boport stage 3 head/2.5 cam , Precision stage 3 50trim .63 turbo, Tial 38mm wastegate, Jangus gutted/ported intake manifolds, 60mm tb, Jangus open dumptube, Jangus 3" elbow, Perrin boost controller,Esslinger adjustable cam pulley, Esslinger small crank pulley, stinger FMI, RFL BOV, Spec stage 3 clutch, B&M short throw, 140 speedo, Walbo 255lph, BBK fpr, 3G alternator, ARP studs.  Be faster... :poke:

baaaaad gas mileage

Reply #13 –
TPS, poke a wire with voltmeter (the one that goes 1-5 volts) move throttle to open and closed, if there is a dead spot any where its bad.
88 Turbocoupe: Coast High Performance 331 kit 28oz balance, Comp XE264HR14 cam, 58cc 185 afr heads, 1.7 roller rockers, Mass-Flo EFI (was POS to setup and their techline is a joke at best)
Full 1 5/8 primary equal length headers, 2 1/2 exhaust, Full manual reverse VB c4 and baked off clear coat "BECAUSE RACECAR"

baaaaad gas mileage

Reply #14 –
Get codes.

Also, you said that you swapped turbos.  Since you're running the stock ECU, did you reconnect the orange wire that was originally connected to the old turbo?  It's an O2 ground, and the 2.3T's on stock ECUs will run like ass if it's not connected.
Long live the 4-eyes!  - '83 Tbird Turbo