Well, looks like I will be tearing into the 1500

[regularman]

Just yesterday I got all the hoses and everything sorted out on the 77 and finally started it up with the DGV on it. I get everything right except a persistant miss on number 4 at an idle. On a rev it picks right up. I tried the usual change the plug out,etc and it still misses on that cylinder at idle. I suspect a cracked valve or something close. The 1500 is new to me. I will first pull the valve cover off and check the clearance. I was told the engine had been recently rebuilt and if the valves were redone, it could be that they were never regauged after the break in and the valve is being held open a bit.

 

[Billm]

Check the cap and wires first

 

[Guest]

Check the cap and wires first

Then compressionj test,.

 

[regularman]

Lots of spark there

 

[nomad]

Right Kim, sounds like a valve. Hope its just tight and not burned. If you hook up a regulated air source (20psi) to a air fitting welded to a oold spark plug housing you can easily determine the leak without a tear down. Check out the MGA GURU sight for details.

Kurt.

 

[AN5Sprite]

Got a vacuum gauge? That'll tell you something...

 

[Morris]

How much idle advance do you have? I have heard that the DVG likes a lot of advance at idle. On my EFI set up, I run 30 degrees advance at idle and the car loves it. Try switching your vacuum advance from ported to manifold and see if that doesn't clear her up.

 

[regularman]

Right Kim, sounds like a valve. Hope its just tight and not burned. If you hook up a regulated air source (20psi) to a air fitting welded to a oold spark plug housing you can easily determine the leak without a tear down. Check out the MGA GURU sight for details.

Kurt.

I might do that. I think I have some of those I made to check this on motorcyles. Don't know if I have the right size though. Common problem on bike was people not doing the break in valve check at 1000 miles or so and the valves would wear into the seat some and end up with no lash and no seal. Simple air pressure in the plug hole and listen for the leak at the carbs or exhaust pipe. I hope its just the lash tightened up and can be fixed with an adjustment. That would be sweet. Otherwise it has all the signs of an exhaust valve problem.

 

[regularman]

How much idle advance do you have? I have heard that the DVG likes a lot of advance at idle. On my EFI set up, I run 30 degrees advance at idle and the car loves it. Try switching your vacuum advance from ported to manifold and see if that doesn't clear her up.

I've played with that. I got the distributor loose and I have not got it to hit on number 4 but on rare occasion at idle and its just hit and miss at that. Yeah the dgv likes advance but not having that that right will show up as the off idle hesitation most of the time, not just at idle. I kept thinking a vacuum leak. The vacuum port is on that side of the intake. I pinched off that vacuum hose and played with that and still #4 is missing. Its still going to be a few days before I can look at it again. Work work work and no play.

 

[Guest]

Might just be a vacuum leak. My manifold always loosens up on me.

 

[regularman]

Might just be a vacuum leak. My manifold always loosens up on me.

I keep hoping and looking for that. It does remind me of a subaru that that had that problem. I found that leak. I am thinking that is not it for this though, I will start on it again next weekend.

 

[Guest]

I like using a propane torch (unlit) to find vac leaks.

 

[regularman]

Ah, never thought of that one. I have used ether and wd 40 but this sounds good.
Hmmn, I have Mapp gas. I need to get a propane bottle.

 

[Guest]

Mapp should be fine. Good thing about using a gas is it''s hard to catch the car on fire.

 

[regularman]

OK, dug into it today. I cut off an old spark plug and tapped it for an air line. I turned the engine to where cylinder 4 valves were closed, then loosened the tappets and made sure there was no possibility of one of them hitting either of the valves. I shot 125psi of air into cylinder 4 where the miss was and the neither valve is leaking. oh, note !! make sure its not in gear when you do this!! the car lunged forward when the piston went to the bottom on #4. turning to where both valves were closed was a waste of time. After the cylinder is at the bottom, then back the tapped adjusters off enough to not touch the valves.
Anyways, 125psi and I could only hear a little blow-by into the crank case. I even took a screwdriver and pried each valve open a little to hear what a leak would sound like and each valve sealed tight as a drum.
I set all valve clearances and put the valve cover back on. The valve train is fine. I put a new set of points and condenser in it. Went to start it up and the distributor made a gear whining noise and spun around and the vacuum valve hit tight against the head. I had to turn the engine backwards to free the distributor up. I must have done something wrong. I pulled the distributor and will tear into it tomorrow.

 

[Guest]

Points on a 1500? Sounds like the dizzle is shizzle my frizzle. it shouldn'ta spun that bad.

 

[regularman]

Yeah, somebody put in a points type distributor before I got hold of it. Don't know what the deal is why they changed it out. The good part is that it looks the same as the one in my 71 so its the same points set and I just got in two new sets from VB because they were on sale. The have the condensers with the orange wire though and I don't really trust those. I bought a dozen Excell condensers off ebay a while back for five bucks and they seem to be great.

 

[Guest]

I bought a dozen Excell condensers off ebay a while back for five bucks and they seem to be great.

If in doubt, hook it to a good battery then toss it to the wife.

 

[JPSmit]

I bought a dozen Excell condensers off ebay a while back for five bucks and they seem to be great.

If in doubt, hook it to a good battery then toss it to the wife.

wow - your post and you "signature line" match.

 

[regularman]

I have tried to test them all sorts of way. In the end its a cap and the only way to truly know a cap is bad is to replace it with a new(hopefully good)one. Caps might still work well in one application but break down in another.
Just so we are all on the same page. Lots of electronic components were known by different names. I guess I grew up with knowing most of them and worked with a lot of vacuum tubes in civilian world as well as the military. I don't know if there is an actual list of these somewhere but here is a few.
Condenser = Capacitor
Choke = Inductor
Valve = Vacuum tube
There are probably lots of you who know more.
I was just listing this for those who wonder why a capacitor is called a condenser, the fact is that Capacitors were called condensers first.