Having a weird problem....

[1988WHTGT]

ok, when I'm cruising in 4th gear running about 50 mph my car jumps around and acts like it has a miss. But if I press the gas hard it accelerates great. Anytime that I've had a motor that had a miss it would sputter when I gave it gas. Have noticed any loss of power; it'll still break 3rd gear loose. Could I be having a fuel pressure problem? Or timing? Its starting to really irritate me and I wanna figure it out. I did a h/c/i swap on it back in March, but its been running fine. The only reason I think of fuel prob is that I've been getting 17mpg driving around a small town everyday and giving it hell.

 

[stang22]

It could be a number of things. Plugs, plug wires, cap, rotor, fuel filter, air filter etc... Basic tune up items. Is your car pulling any codes?

Tim

 

[1988WHTGT]

Haven't tried to pull any codes....and as far as the items you said, they're all new.

 

[1988WHTGT]

Also thinking it could be an O2 sensor??? Cuz its started to smell different too.

 

[stang22]

Haven't tried to pull any codes.

See if it is pulling any codes. O2 sensors, TPS, MAF sensor and a few other sensors could be the culprit as well.

Tim

 

[DJTR]

It might even be timing as well

 

[Thenemesis]

i think you might have a bad wire somewhere.... or ones shorting out and killing the fire to a cylinder and when you hit it the wire moves away from any metal to touch..

 

[1988WHTGT]

How do I go about pulling codes?

 

[90mustangGT]

I'd put my money on a TPS sensor.

A tps will due to wear develop dead spots, in which it will tell the ECU that you closed the throttle, in which the injectors will be shut off and/or the EGR will be opened. You then put the pedal down moving the TPS needle out of that range, now giving the correct signal.

 

[1988WHTGT]

I'll def check that out, but like a lot of the other parts on it, its not very old.

 

[1988WHTGT]

Oh ye, and I know Autozone can't check my codes since its OBD1 or whichever one it is that they don't check. Is there any way to do this without going and buying the thing to pull them with? I'm a poor college student, and really poor after building this motor.

 

[HISSIN50]

Oh ye, and I know Autozone can't check my codes since its OBD1 or whichever one it is that they don't check. Is there any way to do this without going and buying the thing to pull them with? I'm a poor college student, and really poor after building this motor.

Jrichker has links in his post that begins something like,
"Dump the codes..."

all you need is a paperclip. FFI also has code info, as do most repair manuals.

 

[TheUser]

I'd bet on the O2 sensor(s). Same thing has happened in my Jeep multiple times. What I think is happening is, it's not making the proper mixture due to a bad O2 sensor signal so it runs like crap, but when you floor it, it goes into WOT (which doesn't use the O2's) and runs fine. Definately check out Jrichkers post about pulling codes w/ a paperclip.