bad distributor?

I'm starting to wonder if my distributor is wearing out. It doesn't have any play when I grab the rotor but a few symptoms are leading me to believe this might be the case.
On the freeway, even with an electric fan, removed stat, new water pump, aluminum radiator and tranny cooler, the car runs hot after about 10 miles. Now and then, often under increased acceleration, the engine backfires through the carb. And while freeway cruising, I can feel the engine short-out for a moment, for just a split second.
I run a Petronix System 1 and feel confident it's working correctly. Any thoughts, can I test the dizzy some how?

LaGrasta

First I would check the timing chain, new or old, for spretch by watching the rotor while turning the ballancer first clock wise then conter clock wise, any more then 5 degrees of delay when changing dirrection is too much.

Next I would check top dead center against the ballancer timing mark, they do slip.

Next I would check the ignition timing.

Lastly I would check the advance, both mechanicle and vacumm.

Hopefully you will find your problem in one of these areas. It sounds like you are running with retarded (no pun intended)timing.

I'll give your suggestions a try. I'm actually advanced to maybe 14°-16°.

Are you running the Load-a-matic still?

When you say it is shorting out for a second, would you call it a mis-fire or is the entire ignition system cutting out?
My Pontiac had a problem with the system cutting out entirely a couple of years ago.

Does the vacuum diaphram motor hold a vacuum? Pop the distributor cap off and suck on the vacuum line. Are you seeing the mechanism move when vacuum is applied?
Doug

+1 on the timing chain. How old is it?

Seriously, it won't skip a tooth unless massively worn, and stretch won't do that much to the timing in terms of what Anthony has described.

My money is on some issue with the Trepanix - either it's got out of adjustment or is lacking in either reliable signal or voltage supply. Checking with a timing light is the only way to discard this; ear or feel are not suitable references...

Nice thing about the Pertronix, you can pull it out and throw in a set of fresh points and condenser. If it runs OK, you found your culprit.

I have been thinking about this.
When a point type distributor gets wear on the plate, the dwell and gap will change from the movement.

A pickup, pertronix or otherwise, needs a tight gap to work best.

Wear inside the distributor can affect it. I don't know if it would be enough to cause your problems.

I can mail you a spare DSII setup to test it with. This might turn out to be one of those times when a distributor conversion makes a huge difference.

I don't think it will solve the cooling problem unless your distributor is real bad. But, it couldn't hurt. Unless you wipe out the gear and fill the pan with metal.

Any news yet, on the cause?

Stubby he's got a early block DSII won't go. I've seen pertronix work with as much as .050 airgap. I second throwing in a set of points and condensor and check it out. Check for true TDC on the balancer, if it slips it always go retarded. As for the runs hot put a new Tstat back in, you may not be keeping the water in the rad long enough to cool it at higher speed....or if when you were going through the freeze plug ordeal you put stopleak in it and now its plugged up.

I haven't seen this thread in days, then all of a sudden, it pops back up and shows me numerous responses, strange. At any rate, thank you for your advice.

I apologize as I haven't any real follow up for you. I have been working about 60 hours a week for the last 5 weeks in preperation for an upcoming trade show where my company displays (InfoComm09).

I have managed to find my positive terminal was not clean and tight and I cleaned that all up. At times the last few weeks, when starting, it would spark, but then nothing. I'd have to knock on the terminal or apply pressure to it. As Petronix must have a strong feed, I wonder if that could have caused any of this. This Saturday morning, I plan to participate in the Saddleback Church Father/Child car show so we'll see how she runs.
http://www.saddleback.com/blogs/communi ... entID=2453

I did buy another 180° stat to put back in. Removing it did nothing to help with overheating at all.

As for replacing the dizzy, if I have to, I might forgo the temptation of the $60 Autozone replacement and find the $400 for CI's DUI set-up. That is such a large amount of money when I've been so pleased with my Pertronix for so many years, but if it can deliver even an additional 5 hp (see website description), it would help as I estimate I'm only about 60hp at the wheels currently.

I'll report back again when I know more. Thank you so much for all your suggestions and test procedures. I wish you guys were around the corner, I'd love to do this together and knock back a few drinks while were at it.

I bought a reman DS II for $40 (Ebay), and a GM HEI module for $20 (Ebay). I'm very satisfied with them.

UPDATE

I reset the Pertronix igniter to .030 and the plugs back down to .045 and it did nothing. The car starts-up quick and runs like a champ perfectly tuned, but still periodically back fires through the carb and runs hot after about 10 miles of driving.

It is now my opinion the exhaust cam lobes are worn. I believe that would explain everything and it's the only thing I haven't checked. I have no idea of how to check it.

In addition, the car is now in Phoenix! My dad lives in Apache Junction where one of his good friends owns a small auto repair shop at his house. He has a full blown set-up there, really really nice. Anyway, my hope is he'll confirm the problem and fix whatever it needs. If it's the cam, should I put something more than stock in? I still run a stock exhaust set-up so it may not help to run a bigger cam anyway.

I'll be picking up the car in about a month and hopefully I can meet up with some of you who live out that way at a car cruise or weekend show. It will be fun cruising it in AZ.

–Anthony

that is a drag. sorry to hear you are still having problems. how did you get the car to AZ?

LaGrasta":2k80zqgl said:

UPDATE

I reset the Pertronix igniter to .030 and the plugs back down to .045 and it did nothing. The car starts-up quick and runs like a champ perfectly tuned, but still periodically back fires through the carb and runs hot after about 10 miles of driving.

It is now my opinion the exhaust cam lobes are worn. I believe that would explain everything and it's the only thing I haven't checked. I have no idea of how to check it.

In addition, the car is now in Phoenix! My dad lives in Apache Junction where one of his good friends owns a small auto repair shop at his house. He has a full blown set-up there, really really nice. Anyway, my hope is he'll confirm the problem and fix whatever it needs. If it's the cam, should I put something more than stock in? I still run a stock exhaust set-up so it may not help to run a bigger cam anyway.

I'll be picking up the car in about a month and hopefully I can meet up with some of you who live out that way at a car cruise or weekend show. It will be fun cruising it in AZ.

–Anthony

Click to expand...

I happened to have a neighbor driving near my dad's house in Apache Junction with an empty trailer. I had plans to visit him in a few weeks anyway so I'll tow it back with my Astro with a one way rented trailer, unless I can barrow one before I leave.

that was a lucky break, a free ride, nice!

LaGrasta":2odvx48i said:

I happened to have a neighbor driving near my dad's house in Apache Junction with an empty trailer. I had plans to visit him in a few weeks anyway so I'll tow it back with my Astro with a one way rented trailer, unless I can barrow one before I leave.

Click to expand...

7/1/09 UPDATE

My AZ mechanic said he sent the head out to be fixed due to a burned valve. I hope it's just being repaired and not entirely rebuilt as I just did that 8,000 miles ago. He said this is the reason for the high heat and backfiring. He also said the lifters should be turned about 1/4 to 1/2 and these were turned 2 1/2 turns. He suggested I go back to the mechanic that did this. I would but he's since retired so I'm out of luck. I pick the car up in 10 days.

Anyone happen to be coming this way with an empty trailer? At this point, it seems I'll be renting a one way U-Haul trailer rental.

Picked it up this past weekend and it's never run better. I can't wait to get it out and put some miles under it!

As an after thought here LaGrasta, I have follwed this subject and it makes perfect sense to me now, in my opinion it was two fold, the head and the pertronix, the pertronix will not work properly if it gets to hot, I used the P1 and P2 early in my build and all kinds of weird things would happen when the pertronix would get to hot under the blower bracket, I put points back in and it ran fine and then I put a mallory in and have not had a single problem. At present I put a hood scoop on with a radiator fan to remove under hood temps since my engine temp has always run under 180. I would have used a DUI hands down over the mallory except I needed a good dizzy with a smaller cap closer to oem.

Glad to hear you are back up and running good.

My much newer Cougar never was running hot but I too had one burnt valve that actually caused it to fail the California emissions test for high hydrocarbons. I had worked literally everything else. Even the compression was up to snuff . My mechanic was scratching his head and simply could not understand why it was failing at idle. When I finally gave up and brought it to him I had managed to bring the HC levels down to just failing by 3 times the limit rather than grossly high at 10 times over the limit.

I finally pulled the head and took it to the machinist. He replaced one valve and reground everything else and when I put it back on I couldn't believe the difference. Runs fantastic. I probably have all 88 hp now. :mrgreen: I had a slight miss at idle before that's now gone and the max vacuum was about 17. Now I get 20" even at 2,200 foot altitude where I live.

I just have that hot starting problem now that only occurs on the first restart of the day. But she runs fantastic.