- This topic has 10 replies, 8 voices, and was last updated 7 years, 12 months ago by
.
-
Posts
-
Odd Question,
How much should a VW engine move within the engine compartment? I remember as a kit watching how much the engine rotated on a friend’s baja bug and it seemed like a lot. That was a long time ago. My engine does seem to move a lot on the rotation axis, at least compared to my other cars.
thanks, Greg
Hmmmm. Never noticed mine moving during the many times I’ve been back there revving the engine while adjusting timing and carburetor. Doesn’t seem to rock side to side at idle either.Of course now I might be able to see some movement if I actually watch closely next time, having heard it’s possible.And I actually remember when I first got my TDr, thinking maybe the VW engine will do just that, rock side to side because of it being a flat 4. I didn’t really know what to expect.Someone else might have ideas for you to check on. I’m thinking maybe flywheel/clutch not balanced, front pulley, or fan… could be anything I don’t know enough about. Not even sure how the engine mounts to frame.Here’s a link to YouTube (not mine) showing a newly rebuilt VW engine being started and running at low and medium RPM.Only rocks when cranking over at first and it’s just sitting on a cart outside of a VW bus, other than that I can’t see obvious movement (except camera).[TUBE]VPCZXrjg8iM[/TUBE]Startup is at 1:30 time into video.LRH2016-04-11 18:04:44
A very slight twist to the right is normal. Something like 1/4″ or so, at the right cylinder head tin. You typically won’t even notice it unless you’re at the rear of the car revving the engine then letting off it.
Anything really noticeable means your motor mounts are likely worm out and need replaced. They are rubber with metal plates moulded in. After years of use, and exposure to heat, air,oil, dtc., the rubber gets softer and the molded in metal mounting plates can come loose. There are two mounts on the metal cross-member that bolt onto the ends of the frame horns. These are easily replaced, once the engine is removed. It’s advisable to replace the front transmission mount at the same time. That one is more involved, since you must disconnect the shifter linkage and clutch cable (in addition to the two rear mounts described above) and slide the transmission back to remove the old mount. You may or may not also need to disconnect the Grounding cable (that grounds engine/tranny to the frame) and the starter wires depending on your unique car.
Early FF TDr on 69 VW pan
Slowly coming back from the ashes...Yesterday I did my first tune up on the Duchess.
Adjusted the valves, not hard all after reading the directions a few dozen times. They were all tight, I assume the shop adjusted them to .004, but could not verify as I do not have a .004 feeler gauge.
Found the oil leak, one valve cover gasket had not seated well and was pinched at the corner.Adjusted the points – slightly tight
Replaced the plugs – did not look too bad but had no idea how old they are.Still need to check timing and adjust carburetor. Idles much smoother with less engine wobble. Idles too fast, about 1150, starts to slow down and sounds like it might die, then recovers back to around 1150. Hope fully the timing and carb adjustments will solve this.
Did find the idle cutoff solenoid loose, tightened it up and the engine run-on went away.
All in all a good day under the car.
I love progress!
Nice work Greg!Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica RoadsterIf you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)
I have now had my car home long enough to work on it some. I had a friend come visit and he’s a mechanic, so he’s been helping me. First he fixed the throttle linkage that was bollixed up by the “professional”, who simply attached it backwards and to the wrong hole — it couldn’t return all the way back to idle. The revised linkage completely solved the idle problem and now it can even be adjusted. However, when we reduced it down to about 800 rpm, we noticed that the engine was really shaking a lot and you could smell unburned hydrocarbons.
My friend decided that it had a miss, but only an occasional one, which explains why the engine seemed to run okay for me. I think it has been this way from the start but I have driven it so rarely, and with the idle speed so high, that I simply never noticed. The miss is occasional enough that it’s not very noticeable at higher rpms. However, after thinking about it, I always wondered why my tach would occasionally jump very erratically. And no doubt if it was fixed, the whole engine would run so much better. It’s been screwed up since the start and I was just too dumb to know it.The “professional” had installed MSD 6 Offroad PN 6470 electronic ignition and MSD distributor, but used the old stock coil and plug wires. My friend tested the distributor using a crude method: He pulled each wire off at the distributor and saw how much of a shock he got at the distributor. He did the same thing at the spark plug end. Same result: Cylinder #s 2, 3, and 4 all gave a really good shock and #1 gave a weak shock. Now we are trying to figure out why.The distributor cap shows new and clean, nothing evidently wrong. My friend tried using dielectric grease on all the connections, shined up the connections on the distributor cap with fine sandpaper, and checked the gap on the plugs, all to no effect. Now he is trying to check the timing, although I do not understand how timing would cause a weak spark in only one cylinder. We also talked about having me replace the distributor cap and rotor with a new one from MSD, as well as going to an MSD coil and spark plug wires while I’m at it. I hope I am up to it and that it works — he has to go home tomorrow.Any other ideas why #1 cylinder would produce a miss?johnsimion2016-04-21 21:03:12
Sounds like your friend knows what he’s doing.
There aren’t many things that will effect the spark at only one cylinder.
Since he checked the spark
at the distributor, it is not likely to be a plug or wire but the easy way to check them both is to move #1 plug and wire to another cylinder and see if the “weak spark” moves to the new cyl also. If so, then replace both the wire and plug. (It is not always possible to tell if a plug is good by looking at it.)I would suspect the distributor cap. It is possible that #1 lobe on the distributor cam that causes the points to open when the rotor is pointing to #1 cyl is wiped. To cause the miss that you are describing, you might be able to see or verify this with a feeler gauge. Check the point gap at all 4 positions of the rotor, not just #1, to confirm. If #1 is significantly smaller gap than the others, then you would need to replace the distributor. Highly unlikely, but possible.
See if Kent or Ed (heck there’s a whole bunch of guys who may have a better idea than me) comes up with anything else. This is a very strange problem if it is not the cap or wire or plug.
FYI, my friend has now decided that the problem lies in the “non-MSD” coil. He told me to replace the distributor cap, rotor, AND put in the MSD coil that is made for the system. The stock coil came with the car when I bought it, and for all I know it came with the original donor car in 1979. Regardless, he believes that the stock coil may either have some bad wiring or else may simply be unable to provide enough electricity to fully power the MSD distributor. Or something like that. At least these parts aren’t ungodly expensive and I think I can figure out how to replace them. I also plan on replacing the spark plug wires and coil-distributor wire while I’m at it. If that won’t work, I’ll be stumped again.
At least the good news is that he got a lot of other work done for me. Apparently this kind of thing relaxes him while our wives chat-chat-chat. I will post that separately because I think the info might be useful to others.
- You must be logged in to reply to this topic.