1990 Mustang 2.3L bad highway driving

90MustangLX2.3L · 09-09-2007

Like the title states my Mustang is probably the worst car I've ever driven on the highway. I will be driving at about 65 MPH and it's almost like the gas cuts out. Then it will back fire 10-15 times before the rear end fells like it'll rip out. I'll get a picture tonight of what comes out the exhaust.

sleeper_inc · 09-09-2007

When was the last tune up done???

Also check you're timing belt, it might be missing teeth

05Musclestang · 09-09-2007

sorta off topic but I took my '90 out the other day on the highway for an hour, definitly cleaned that car out. I burried the needle laughing. Didn't feel like we were going that fast but I thought it was funny that the thing actually went over 90 mph

sleeper_inc · 09-09-2007

I can get my car doing 100 before I have to back off

Aimbot1 · 09-09-2007

I can barely get mine to 70 /sadface

My'StangOpens · 09-11-2007

^then you need a long enough road or a tune-up real bad lol

spencer87 · 09-16-2007

Do a realy good tuneup. It should be able to go 85 before the factory speed limiter kicks in.
-plugs
-wires
-O2 sensor
-air filter
-clean the MAF sensor (there is a special spray for this, if you can't find any then leave it alone!)

If this dosen't help please post how the engine sounds at its top speed.

Blue Notch · 09-22-2007

Just curious, what should the rpms read at about 70mph?

Aimbot1 · 09-22-2007

mine is normaly at 1700 at 70mph
i can never get it to go over 2k unless I manualy shift

and yeah mine cant go over 70 cuz my exhast manifold ghasket is blown im fixxing this weekend so should be better if not /sigh idk WTF to do

Aimbot1 · 09-22-2007

Quote:

Originally Posted by spencer87

Do a realy good tuneup. It should be able to go 85 before the factory speed limiter kicks in.
-plugs
-wires
-O2 sensor
-air filter
-clean the MAF sensor (there is a special spray for this, if you can't find any then leave it alone!)

If this dosen't help please post how the engine sounds at its top speed.

BTW all that you said is brand new + alot of other parts new, and I just ordered my K&N and will be in tomarow

spencer87 · 09-26-2007

I have no clue as to what it could be then. Try getting your injectors tested, cleaned, or replaced, and check to see if the timing is correct. If this dosent help then i suggest taking it to a mechanic you trust.