I have a '89 F-150 with a 302 engine. It has 160000 miles on it. It has a four speed transmission. When it is lugging,it misses and I experience power loss. Also, when I pull up to a red light the rpm's keep going up, then suddenly dropping. Any suggestions?

 

Could be a lot of things:
The exhaust manifolds of those trucks have a tendency to crack. If those cracks have been there for a while, you might burn your valves and hence the miss.
Then the emissions system might act up and mess with power and rpm's. Culprits there may be the O2 sensor or the EGR valve. Difficult to say if there are no computer trouble codes. Check your vacuum lines for leaks, your exhaust manifolds for cracks and apply vacuum to your EGR valve to see if it holds a vacuum.
The idle air control valve controls idle rpm's, you might want to check that too (could be clogged by carbon deposits).
Many things. Check some of it and let us know if it helped.

 

Thanks for the reply Bjoern. As a matter of fact, my manifolds did crack a few years ago and I replaced them with Hedman headers. I checked the vaccuum lines and did find a crack. I will fix that and replace my o2 sensor and EGR valve then get back to you. Thanks again.

 

Isn't the RPMS increasing at idle a symptom of a bad idle air control valve?

 

Isn't the RPMS increasing at idle a symptom of a bad idle air control valve?