ClassicCar

TOM-WA-

My car runs fine at idle and accelerates fine till the
RMPs increase. Then in all gears it will not speed up.

It feels like there is a governor on the motor that will not allow
it to go past a certain RPM?

Any thoughts and what should I look for to trouble shoot?

THANKS

Geoff C., N.Z.

Sounds like either a bad fuel pump (not enough pressure to keep the fuel supply up), blocked or restricted pipe, blocked main jet, or it could be something as basic as low coil voltage (dirty ignition switch contacts or connections). You really have to go through a process of elimination to find such a fault. I had a similar problem on a '50 Pacemaker some time ago, and it turned out to be green gunk in the fuel line. I put STP carb cleaner in the tank which did the trick. Good luck.

RonS

Does it rev up in neutral? Do you have a standard or auto tranny? Have the carb(s) been touched recently? How about timing, as well as verifing if the advances are operating. Was the distributor removed and placed back in correctly? Is the coil wired properly for a positive polarity( if so, as original on 55 and older cars unless changed to -ground)? What year is the car? We could use some more info. Also a exhaust restriction could occur.

RonS

Right Geoff, forgot the fuel pump, Need to pressure and suction test.

Steve E

Years ago, while working as a mechanic at a Texaco station, a customer brought in a 65 or 66 Mustang, 6 cyl automatic, said it had no power & wanted it tuned up said the power had dropped off gradually. I tun ed it up, took it for a road test and it wouldn't go over 20 mph! Engine sounded great. By process of elimination finally got around to disconnecting the exhaust pipe at the manifold, it took off like a scalded dog, hooked it back up & took it to the muffler shop. This was shortly after aluminized pipes and mufflers came out. The outside of the pipe looked fine, but the inside had collapsed cutting an inch and one half pipe down to less than one inch! Replaced the exhaust pipe and that was the end of the problem! BTW, this was in 1966 or 67, so the car was almost new.

forjack842

If the throttle butterfly is all the way open it sounds like a high speed jet is plugged.
If it was stalling out at speed I would bet on a fuel pressure/pump issue

Jack

TOM-WA-

I am running an electric fuel pump and have a pressure regulator installed in line.

What pressure should I be running?

The car is a 3 speed stick shift

51hornetA

If the fuel pressure checks out ok check the condensor. Bad condensor can give these types of symptoms.

Park_W

I've seen two problems that can create this situation:
1. Bad ignition condenser (though in these cases the engine would barely run above idle)
2. Frozen centrifugal advance mechanism in the distributor. This one behaved identically to what you've described. Car wouldn't go over 30 mph. Found the advance mechanism rusty and stuck. Cleaned and light oiled, and all was well.

RonS

4-4.5 PSI. The electric is actually pumping, right? They can sound like the pump is at work, but little or no gas is moving through. Then the mech pump(if there is one) will be restricted, especially under load. What type of restrictor do you have? If it's a dial type, they can be suspect for accuracy.

Ken U-Tx

Weak breaker arm spring tension can cause point bounce or float at higher rpms, that would cause said "governor effect". Kenneth

Sarah Young

I think it's having sympathy pains for my Jet.

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