View Full Version : 86 ts6m carb accelerator pump question
tom26
06-08-2014, 12:12 PM
Boat is a 86' ts6m w/ pcm 351, holley 4160 carb.
What accelerator pump cam do you use?
Currently using holley 330 pump cam that came with a replacement carb and having stalling problems on accelerating from idle.
Thanks,
-Tom
92SupraComp
06-08-2014, 01:20 PM
Might not be the acc pump. Another cause of hesitation is the power valve.
In general...and this is very general...stalling is from a lean condition. A rough stumble is from a rich condition...and often accompanied with black smoke from the exhaust.
So, if your stalling, I'd first try a larger burst for the accelerator pump. Of course, look in the bore when you move the throttle and make sure the pump is actually working first. After doing that, if it runs fine for a couple seconds on acceleration and then stalls, you could have a power valve stuck closed.
Finally, if the boat has never run well with that carb, you might try going a couple jet sizes larger.
92SupraComp
06-08-2014, 10:52 PM
Careful about going to bigger jets. From PCM these things run VERY rich... If did a mild motor build and new Carb with the right jets or even efi, you would use much less fuel...
tom26
06-09-2014, 01:58 PM
I am sure the accel pump is coming in too late with the pink 330 cam. According to the holley chart it has the least amount of lift in the first degrees of rotation.
Moved the cam to the 1 position and shimmed the arm spring and it made a big difference.
As for the stalling it was during the initial jump from 600 to 900 rpm with or without load. Idles at 600rpm, over 900 rpm it runs perfect. From an idle if throttle opened to quickly it would stall.
Now with the cam moved it hesitates just a little and stalls 1 out of 10 times.
Still wondering what cam color or part # other people are running.
Going to try a new accel pump arm and the red holley pump cam (240)
92SupraComp
06-09-2014, 04:20 PM
speed up your idle. If you go straight to WOT or near it, that is too much for the motor...
Jetlink
06-09-2014, 04:32 PM
Speeding up your idle might not be feasible and if set too high to mask another problem might create other headaches.
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