Car shakes violently accelereting at low speeds

Status
Not open for further replies.
I'd look at ignition and fuelling first, check timing and compression and if that doesn't bring you any joy then its YB time
smile.gif
 
the ignition is set at 12 BTC i think which is spot on in the middle of what ford reccomends which is 10 to 14, the carb is running a little lean though so i will look at that first
 
Originally Posted By: MolaKule
Universal Joints, worn splines?
+1
The young folks have forgotten what a driveshaft problem on a RWD car is like.
 
I'm on a Capri group on FB and a guy said this to me :
"You didn't adjust the timing did you as that will cause it to vibrate more at low rpm and speed as when on motorways your using fast running side of things including jets in carbs so it could be that, it's passed mot now try enriching it see if any difference. If I make mine too lean the whole engine rocks."
Does this make sense to you, it does to me
 
Only hot (not cold) rules out driveline (u joints, cv joints, driveshaft bearings, etc.).

My money's on a misfire. Bad plug, cable, coil, or injector...possible vacuum leak causing lean running but shaking is usually one cylinder not firing.

No check engine light?
 
Originally Posted By: Astro14
Only hot (not cold) rules out driveline (u joints, cv joints, driveshaft bearings, etc.).

My money's on a misfire. Bad plug, cable, coil, or injector...possible vacuum leak causing lean running but shaking is usually one cylinder not firing.

No check engine light?


Its a 75 Ford. The owner mentioned he leaned out the carb, I would try putting the carb back and seeing if it settles out a bit. You may be running rough under load while hot due to being too lean.
 
Wow, emissions checking a 41 year old car? We thought we had it bad here in the USA! My money's on the carb as well, especially if it started after the mixture was leaned out.
 
Originally Posted By: FordCapriDriver
Motor mounts are new, the u joints are a couple years old, could it be the driveshaft bearing?
only happens when the engine is up to temp btw


Only accelerating and only when up to temp? Sounds like a heat related ignition issue.

Carburetor in '75, so I would look there. I had one carb that I rebuilt, ran great when cold but then would not function 1/2 as well when warmed up.
 
Last edited:
The adjustment on the carb usually only changes the idle mixture. To change the running mixture you'd have to take the carb apart and swap out jets. Clearly no one has done that between when it was running OK and now.

So I'd be looking mostly at the ignition. Misfiring at low rpm and heavy throttle commonly is because the sparks are weak. Look at the cap rotor and coil for cracks. How old are the wires? Are they of good quality? Some parts store wires only last for a year or so. Idle the engine at night and look under the hood at ignition parts for any stray sparking.
 
I will look at the ignition and carb then, it has points ignition and a Weber 38 DGAS carb, and yes even classic cars here have to pass an inspection once a year where they check the brakes, emissions etc... mine usually passes the test just fine when the carb is set up right and the engine is nice and hot, somebody asked about a check engine light,my Capri has no check engine light
 
Status
Not open for further replies.
Back
Top