289 Engine issue when put into gear.

[KnightRider]

Well after selling my 79 mustang back in 2000 We have finally acquired a 1965 mustang. We have had it about a week and a few days ago it the 289 "A" code, seems to run rough once its put into gear. It seems to idle just fine. I recently replaced the battery, alternator and voltage regulator along with spark plugs cap and rotor. I've also noticed wiring issues when I just up and lost power a few days ago and found cleaning off the connections at the starter solenoid solved the issue and restored power. When it is put into gear it acts like it is struggling to keep turning the engine, when the gas peddel is depressed it run just fine. It seems like the engine was recently gone though, starts great, dose not burn oil, sets you back in the seat when you get on the gas. Any ideas what could be possible contributiors to the issue or where I should start to try and find possible causes. Also a few days after replacing the regualtor and alternator the alt light tends to blink on and off until you get on the gas, then it stays off until a stop light or something.

Thanks,

Knight rider
1965 Mustang "A" code 289
1966 F-250 352 V8 Custom Cab / Camper Special
1958 Mercury Monterey MEL 383 V8

 

[horseballz]

KnightRider,
For the rough idle, check your ignition points (condition, gap and/or dwell) and your timing. For the ALT light, my guess is that your idle RPM is dropping low enough, from the rough idle, that the engine/alternator isn't turning fast enough to provide proper current. IE: if you fix the idle issue, it will likely cure the ALT light issue.
HTH,
Gene

 

[Az Pete]

Check the vacuum modulator if it is an automatic....C4 tranny. Otherwise, it is just getting the right tune on the engine.

 

[KnightRider]

Thanks for the info, I'll check the modulator. and see if that is the issue, It was converted to a pentronix electornic ignition before I purchased it. It has been ideling fine until a few days ago. Makes sense about the alt light. TIme to pull out the chilton from 1965

Thanks for your input I appriciate it!!

Knight rider
1965 Mustang "A" code 289
1966 F-250 352 V8 Custom Cab / Camper Special
1958 Mercury Monterey MEL 383 V8

 

[Az Pete]

Pertronix have been known to go bad. Might try a set of points and condenser if nothing else works.

 

[bartman]

Check all the vacuum lines, any leaks will cause bad idle. Been through that many times. Pertronix can go bad, I have had one for 5 years. I would look at vacuum lines first though. Bartman

 

[68RCodeConv]

Carburated engines can idle drastically differently depending on the climate. My 67 GT350 idles at 900 rpm on a cool dry day versus 750 rpm on a hot humid one. That is without changing anything.

It could be that a climate change has degraded your idle quality just enough to push you over the edge. Try adjusting the idle screws or simply increase the idle speed.