Benefits of Chip

Hello, I recently did a full rebuild on my 90 SC and am not getting the power or the decent fuel economy I was looking for.

First off, I know its not a smart car but i was looking to be better than my jeep.

So i overbored the block and machined eveything but other than that she is currently stock.

Would a chip increase power and economy? I am getting about 20 mpg currently.

It smells like it is running very rich and that mpg is based on pure highway driving.

Any advice would be appreciated.

Replace your 02 sensors and clean your MAF sensor. If it's running rich it's possible that cats have been damaged. How much vacuum does it pull while cruising at 70mph on level ground? Has the octane plug been removed?

A chip generally will not help mileage, but general maintenance can do wonders. Sometimes a certain amount of gain can be had from a chip, but stock highway mileage should be about 24mpg. 20mpg isn't all that bad but it could certainly be better. What oil do you run in it? Is it auto or 5spd?

02's have less than 5 thousand k on them. Maf was cleaned at the same time.

Very possible that the cats could be damaged.

It is an auto tranny.

On an all highway trip from Minnesota to Colorado last summer, my 89 five-speed averaged 28.5 MPG. I clean the MAF sensor regularly and have brand new plugs and wires. Also, I put in the highest octane gas I can find, usually 93 at BP or nonoxygenated if I'm near a station that sells it.

My SC is stock with no chip.

28mpg!!!
I wish I could get the 24mpg everyone talks about. I average 19-20 highway. Last long road trip I did from NY to NC and back I got 21 at the best from my 89 5-speed.

Guess I better clean up my MAF and figure out the best way to change the plugs.

But I'm not to worried as the old SC has been sitting in the driveway more and not been driven a lot lately. Hot weather in NC and my AC don't work.

I don't think a chip is necessary to achive low to mid 20s in mpg. I currently have a 90SC auto with 10% SC pulley, full intake with upgraded mass air and TB, 38lb. injectors, 190lph fuel pump, headers and full exhaust and I am averaging between 23 to 25 mpg on the highway. I would recommend doing a good tune up and close the gap on the plugs. Just my .02 cents.

I had like problem with everything replaced & found my TPS was out of calabration. If you have a non-OEM throttle body you must make sure it reads .93 at idle. I missed this some how till a CEL illuminated. This was on an 89 5 spd. The 1st thing weird was my cruise controll would add 3-4 MPH to my set speed... Go here & do an audit.

http://www.fordfuelinjection.com/

AB's91SC said:

I don't think a chip is necessary to achive low to mid 20s in mpg. I currently have a 90SC auto with 10% SC pulley, full intake with upgraded mass air and TB, 38lb. injectors, 190lph fuel pump, headers and full exhaust and I am averaging between 23 to 25 mpg on the highway. I would recommend doing a good tune up and close the gap on the plugs. Just my .02 cents.

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While your car seems to be running ok, its not optimal. You'll be right at the max that adaptive can work while trying to lean out your overly rich condition while cruising, and at WOT you're more than likely hitting 10 AFR or richer so you're leaving performance on the table.

For example, you went up 26% on injector size, which means that for every injector pulse the computer commands, you are dumping in 26% more fuel, so now adaptive comes in while your cruising and tries its best to pull that 26% out but here's the caveat, it can only do 25% either way... now lets look at WOT, the car is commanding a 10.9 AFR when you have your foot to the floor.... now add 26% more fuel to that.......

Just saying .....

Fraser