Posted By |
Discussion Topic:
Accelerating before shift, then bogs down
-- page:
1
2
3
|
|
dggohl |
06-12-2016 @ 7:47 PM
|
|
|
Member
Posts: 33
Joined: Jun 2014
|
Hi, I just put a 53 mercury 255 into my 52 Mainline. At idle the car runs great. But when I accelerate just before the shift the car bogs down with that jerky motion, hesitation. I thought it might be the accelerator pump, replaced it, i little better but problem still persists. I also turned out the jets about a half turn. No change.
|
40 Coupe |
06-13-2016 @ 4:42 AM
|
|
|
Senior
Posts: 1698
Joined: Oct 2009
|
Make sure the distributor advance is working properly. Can do this with a timing light. Put a vacuum gauge on the engine and look for results.
This message was edited by 40 Coupe on 6-13-16 @ 4:44 AM
|
dggohl |
06-20-2016 @ 6:44 AM
|
|
|
Member
Posts: 33
Joined: Jun 2014
|
Hi, the timing is right on. I checked the vacuum and it shows on constant 18 on the gauge at idle. Could this be something with the fuel pump?
|
TomO |
06-20-2016 @ 7:10 AM
|
|
|
Senior
Posts: 7274
Joined: Oct 2009
|
I believe that 40Coupe meant for you to watch the timing marks when operating the accelerator. You should see the timing advance. Turning the idle mixture screws (what you called jets) will only affect the idle. Do you have the Mercury carburetor and distributor or the Ford ones?
Tom
|
dggohl |
06-20-2016 @ 8:17 AM
|
|
|
Member
Posts: 33
Joined: Jun 2014
|
I have the Merc carburetor on it.
|
dggohl |
06-20-2016 @ 8:18 AM
|
|
|
Member
Posts: 33
Joined: Jun 2014
|
And, the Merc distributor is on with the Ford distributor cap.
|
TomO |
06-21-2016 @ 8:16 AM
|
|
|
Senior
Posts: 7274
Joined: Oct 2009
|
Run the car until the engine is at normal operating temperatures. Shut off the engine, remove the air cleaner and operate the accelerator linkage while observing the carburetor. You should see 2 streams of gas. If you do not see them, your carburetor needs to be rebuilt. If you see them, the problem is probably in the distributor. Set the idle speed to 450 RPM. Disconnect the vacuum hose going to the distributor and check the timing. Adjust it if it is not 2degrees BTDC. Connect the vacuum hose and recheck timing. Accelerate the engine while watching the timing. It should advance. If you have a vacuum pump, try applying 7 inches of vacuum to the vacuum advance. It should hold the 7 inches. If not the diaphragm is bad.
Tom
|
juergen |
06-23-2016 @ 7:21 AM
|
|
|
Member
Posts: 259
Joined: Jan 2010
|
Tom, are you sure that the timing should advance on acceleration? I thought in normal cruise (high vacuum) the fuel ratio is lean and takes a longer time to complete combustion, hence maximum advance. On acceleration, the vacuum goes down, the fuel mixture is richer and less time is needed for combustion. So like disconnecting the vacuum, the timing is retarded.
|
TomO |
06-23-2016 @ 7:54 AM
|
|
|
Senior
Posts: 7274
Joined: Oct 2009
|
Juergen, you are correct during acceleration, the timing will not advance, but once the engine is at a steady speed you will see advance from the vacuum advance. There are no mechanical advance weights in this distributor, the timing is controlled by the springs inside the distributor and the vacuum advance. This is just a rough test. The better test is to have the distributor set up on a distributor machine by a qualified operator. Again, I am sorry that I did not make myself clear.
Tom
|
dggohl |
06-23-2016 @ 9:07 AM
|
|
|
Member
Posts: 33
Joined: Jun 2014
|
Tom, I have gas coming out of both jets in the carburetor. If it is the distributor, what would be at fault to cause the hesitation? Thanks in advance for your feed back.
|