| Slant Six Forum https://slantsix.org/forum/ |
|
| timing mark jitter https://slantsix.org/forum/viewtopic.php?t=34912 |
Page 1 of 1 |
| Author: | ppsi [ Fri Apr 17, 2009 5:36 pm ] |
| Post subject: | timing mark jitter |
I've got a slight stumble in my 65 dart at idle and I imagine underway as well. I tried adjusting my Holley 2280 as best as I can but it still needs to rev at 750 rpm to not stall and this means over a grand at idle (automatic). I did a total tune up-w-wires, cap, autolite #26 plugs, and the dist has a pertronic unit. It isn't a fuel volume issue but I suppose could be a carb issue but when I put the timing light on it (I have some sort of tube on the timing chain cover but I don't use this for timing) the timing stays steady at 3 degrees btdc and then it dips for one rev to about 6-7 degrees btdc and I hear the engine sort of miss-not a total misfire but a break in the otherwise smooth idle. This happens every 5-6 timing revs I'm thinking of putting a new coil on it but would greatly appreciate any other thoughts. BTW I'd like to replace instead of rebuild a BBD I have and would like a new BBD. Are these available at a decent price? |
|
| Author: | Mister_Perkins [ Fri Apr 17, 2009 6:26 pm ] |
| Post subject: | |
Have you rebuilt the carb? Sounds almost like its getting too much fuel. I know if I rev my holley 1945 up 5-6 times while idleing it will cut out a little bit. My exhaust valves are bad too though so theres always a little popping in the exhaust anyways, but it does just what your saying not a total miss but a pause in the idle. |
|
| Author: | ceej [ Fri Apr 17, 2009 7:32 pm ] |
| Post subject: | |
SlantSixDan may have some NOS BBD's left. Shoot him a PM. Have you fully checked the health of your distributor? Bushings, gear and so forth? CJ |
|
| Author: | ppsi [ Sat Apr 18, 2009 4:02 am ] |
| Post subject: | |
I have not pulled the dist to look at it. I figured I would get some experienced info here first and then take the past of cheapest and least resistance. A coil is cheap and I don't remember replacing it. I do want to change the carb regardless however so I'll see if SlantsixDan has one. Thanks Howard |
|
| Author: | Pierre [ Sat Apr 18, 2009 4:15 am ] |
| Post subject: | |
Did that tuneup include a valve adjustment? Wouldn't hurt to do a compression check too, this sounds similar to what mine did when one of the valves was burnt. |
|
| Author: | Reed [ Sat Apr 18, 2009 7:40 am ] |
| Post subject: | |
Is your engine original to the car? I ask because the factory wasn't using tubes on the timing tab in 65. Those tubes are for a magnetic pickup used in later (much later, like late 70s and 80s) motors. If the motor is original, someone might have changed the timing chain cover. What side of the motor do you read the timing marks from? Passenger or driver? Can you post a picture of your timing chain cover and timing tab? The reason I ask is that if someone has changed the timing chain cover only then the timing mark might be in the wrong place to give an accurate reading. |
|
| Author: | slantfin [ Sat Apr 18, 2009 11:48 am ] |
| Post subject: | |
Quote: if someone has changed the timing chain cover only then the timing mark might be in the wrong place to give an accurate reading.
What about finding an accurate TDC to check the timing mark? You can make your own mark with some paint if it's wrong.
|
|
| Author: | ppsi [ Thu Apr 23, 2009 4:51 pm ] |
| Post subject: | |
The motor is from a 1978 Aspen and I took it directly to an engine shop after getting it where they did the lower end while I did some head porting/blending. Then they did the installation of the head etc so it is not the original motor obviously. I will have to take out #1 plug to verify the timing/TDC because It has been a long time since I did this job and I can only recheck to verify and I'll set the timing at ??? I did check the valve lash and it is fine. The motor only has about 15k miles on it since rebuilt about 5 years ago. I rebuilt a BBD and it now runs almost smooth butit sounds like the timing is off because the sound it makes when turning it over to start it. Thanks-Howard |
|
| Page 1 of 1 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|