RickS

i need some help.
i have a 92 3.1 camaro. i used to get nearly 25mpg. lately it has changed horribly.
my car has 3.42's and the t5 trans. i have replaced the o2 sensor, got new plugwires, new distributor, cap&rotor, new plugs, oil just changed days ago(full synthettics), new oil filter.

also when the car has been sitting, it dosent want to keep running below 2.3k rpms in gear, unless moving over 6mph.
what is causing my bad mileage, and rough cold running?
mabie i need a new fuel filter? is my fuel pump acting up?

the gears are horrible on the beltway, ill run about 3k rpms in 5th going 75mph. still i never went through gas like this.
i left for schooltoday at half tank, and by the time i got home i had 1/4th tank left.
my school is 28miles away, so thats 56miles. i think the tank is a 15.gallon. gas has been getting real expensive so i have to use regular.

i am starting to think i want 3.08 gears damnit. someone save me
thanks in advance

RedIrocZ-28

I have a question here, Why is it that everyone with a lower numeric gear ratio than I, claims to be at a higher RPM than I am on the highway. I have an Automatic car with a .7 OD ratio with 3.73's and I am at 2550 at 75 mph. How can you have a T5 with 3.42's and be at 3000? That doesn't work right.

As for your gas mileage question, how many miles does your motor have on it? It could just be getting worn out.

90rocz

Double check your tune-up:
a couple of switched plug wires,
one plug wire off in where #1 should be,
timing retarded,(bumped or slightly rotated the distributor)
cap on slightly crooked,
coolant sensor bad or its wiring,


Any codes, check engine light???
Does it miss-fire a little?

brodyscamaro

i just got 6.2 mpg so yeah
lol

Markolc

RedIROC - your torque convertor may not be locked up?

RickS

i used to think i may have higher than 3.42's, but i dont think the previous owner put them in...
RedIrocZ-28
whats the final gearing of your transmission?
mine is the T5 has a final gear of .75


my dads 87 roc, had 3.73's and i asked him a wile back, he ran 3k at 70mph2...


plugwires and all the stuff is installed properly, i have no dead cylinders, no powerloss. i think the injectors are fubared

i do have an exhaust leak right at where the CC and t pipe connect, the o2 sensor may be getting false readings?
the o2 sensor is 2 1/2 feet from the leak.

brodyscamaro

if your torque converter doesnt lock it makes the cruising RPM higher then if it is locked

RedIrocZ-28

Rick, my OD gear ratio is .70:1 or however you arrange them. It checks out at thirdgen.org on their equations page. I am gonna go check that out again...

Ok, if you are in fact at 3000 RPM in 5th gear you should be doing 90.xx mph and at 2500 you would be doing 75mph

My calculations tell me that at 2500 RPM in OD with my .7:1 ratio and 3.73's I am running 74mph.

You have somthig wrong there or you have like 4.10's.

TheGreatJ

4.10s or some really severe clutch slippage. In a man. trans setup theres no other reason for cruise rpm to be that high.

Have you checked the car for just a flat-out fuel leak? Gas mileage shouldn't get that bad that fast.....it has to be goin somewhere other than the engine and the ground seems a likely candidate.

aziroc

well when i had my 355, i got like 8 mpg. i had prob like 250-300 hp out of it, so i had no clue y i was getting such a ****ty gas milage. *found out later the fuel pump was crap, and my lines were bad.* but now with my 406 *see sig for #'s* i get anywhere between 18-22 mpg.

RickS

i noticed my fuel pump just started this electric humm.
not the same sound it makes when the fuel lines are primed, its a different sound...
clutch was replaced 8k miles ago with an aftermarket one. clutch dosent slip

is there a way to see if my rear is non stock?
where are the numbers on it?
i know if i take ovv the cover, the numbers will be on the gears?
also in 4th gear its 1.0 on the t5

i think in order to change the fuel pump i have to remove the tank cuz its inside the tank right?

RickS

also, anyone ever hear of the trick where u put the car in its 1.0 gear and at som mph it will read the gearing on the rpms?

i dont know it, anyone?

aziroc

yea.. i beleive what u do is put ur car in D *not OD*and its either at 60 or 80 mph it tells u what gears u have by the rpms. *ex.. if at 80 u r ar 3200'ish rpms.. u ave 3.23.. if u r at 3400 rpms u have 3.42's*

RickS

i checked my rpms' at 3k at different gears...

3000 in 5th gear going 75mph
3000 in 4th gear doing 60mph
3000 in 3rd gear going 40mph

my rear tires are Pirelli supertouring 225/60r/15
the car can slip all of first, and depending on what type of pavement half of second

camaro6

I used to have a 92 3.1L too. The mpg was really bad. The most i ever got out of a full tank of gas was 170 miles. Thats about 11 mpg.