Ghostly Avanti behavior strikes again!

[edpjr]

Why do you need to run such a high octane with such low temp. Is your compression ratio over 11:1? Do you just want to run some crazy timing? I understand an R2 Avanti is supercharged, but I would think it should run fine on premium.

Good question. Unbeknownst to me when I got the car several years ago, the original R2 had been replaced somewhere along the line with an R1 engine. So with the R1 heads and supercharger my car has VERY high compression. It will not hardly run on unleaded 93 octane, let alone perform. I have to use a mixture of 100 and 110 octane racing fuel to maximize performance. I also use some Marvel Mystery Oil in the gas. The timing is NOT set too high.

Oddly enough, this combination of R1 & R2 plus electronic ignition seems to make for an unusually fast car based on what I've read about stock Avanti performance data. I generally don't drive the car alot or put many miles on it. It also helps that my brother is a trained mechanic who specializes in older carbureted vehicles. He can really put the tune on it. Too bad he wasn't with me when it suddenly cut off last nite.

[edpjr]

Two more possibilities...1) A small amount of water (condensate) working its way through the fuel supply can cause an engine to shut down.

2) Microscopic sediment in the bottom of a fuel tank can become "fluidized" from the vibration and motion when a car is underway. This material gets sucked up into the fuel line and eventually packs around the fluid filter element shutting off gas flow. After sitting for a few seconds, this material will settle off the filter element and float back down allowing fuel to pass through again. If this is your problem...it will continue to occur until the filter is replaced.

Thanks for the suggestion. The fuel tank was removed and professionally cleaned and refurbed a couple years ago. All fuel lines, metal and rubber, were replaced. The gas filter was changed out less than a month ago. The 4V Carter AFB has been completely rebuilt with a kit from Dave T-Bow. In fact, the only fuel system component not yet replaced is the fuel pump. Since I already have a NOS Carter replacement pump, I'm planning to change it out just in case there's some latent debris lodged in it. Then I'll get a repair kit and have the original pump rebuilt.

[edpjr]

I had a similar problem years ago with a TR-7 the electronic pickup in the distributor would get hot and fail. When it would cool down the car would run fine again for a while. I replaced the pickup in the distributor and the car ran fine from then on. Also happened to my Avanti ll replaced the pickup in the distributor and cured the problem. I hope this helps.

Thanks. I was wondering about that scenario. Time to call up T-Bow.

[edpjr]

Do you have a pink wire going to the coil? if so replace it with a regular wire and a resistor. Also coil itself could be suspect. NT

Thanks! I'll have to check the color of the wiring. The original coil was replaced with a new High Performance one about 2 years ago. There is a resistor in place as required by the Mallory electronic dist.

[edpjr]

Years ago when I had my '63 R1 Avanti I installed an optical electronic ignition. It ran fine for about a year than suddenly started having issues similar to yours. I went back to points and no more problem.

I'm with the others who have experienced ignition problems...look there.

Yeah, I've wondered about that... I have an original Prestolite dual point dist that I could get rebuilt. But, before I spent $375 on the T-Bow Mallory, I heard nothing but good stuff about electronic ignition from Stude people that had used it. My brother also uses electronic on his 1970 Pont T/A and it has worked great for years. For now I'm more inclined to replace the elec pickup if that's the problem rather than go back to ignition points. But Thanks for the advice.

[edpjr]

Ectoplasm......"who ya gonna call"........

I tell you no lie buddy, the car has produced a substance that looks like ectoplasm before in places where there should be NO leaks possible. And it disappears with no residue or stain left. It does have the obligatory tiny oil leakage around the front seal. I've always thought the car was hainted.

[edpjr]

another "vote" for coil...

If so, it means the expensive high voltage replacement is defective.

[edpjr]

Thanks to everybody for the help and suggestions. I guess I'll take the shotgun approach to this problem. Ordered a new dist pickup and resistor from T-Bow. I'll try to get my buddy at NAPA to replace the Accell coil under warranty. I'll get my brother to check the ignition switch and affected wiring. And, I'll probably go ahead and replace the fuel pump and gas filter just to cover all bases. I can't afford to have this thing suddenly cut off on me when I pull out into the road or highway.

[Buck]

Hey Ed, Jr, I did the same thing Friday night. Mine ran fine and I ran it kinda hard and was having fun with it when it just quit but I was in my driveway by then. I found out today that it's debris from the tank. The fuel pump was not putting out anything. I took the hose off andf blew it backwards with air and replaced the filter and it work fine now. I'm about 2 hours from you so It may be the same ghost.

[edpjr]

Hey Ed, Jr, I did the same thing Friday night. Mine ran fine and I ran it kinda hard and was having fun with it when it just quit but I was in my driveway by then. I found out today that it's debris from the tank. The fuel pump was not putting out anything. I took the hose off andf blew it backwards with air and replaced the filter and it work fine now. I'm about 2 hours from you so It may be the same ghost.

How 'bout that for a coincidence??? Thank goodness you were in your driveway. I had to direct traffic around my stricken Studebaker for about 5 mins in beautiful downtown Denver, NC. At least I was at a stoplight in a 35 mph zone. It would've been nasty if it had quit a few miles earlier on the dark Hiway 16 two-lane 55 mph stretch where 18 wheelers routinely roll along at 65 mph.

I shouldn't have a grain of debris anywhere in the fuel system, but I'm gonna change out that dang fuel pump for sure (along with everything else that could be the problem). No matter how great a car looks or how good it runs, it's dangerous if it justs cuts off on you without warning.

[edpjr]

Updated: Discovered that high perf Accell coil was leaking oil, substantial amount of oil. Replaced it and the coil resistor. Also checked out the wiring to the ignition switch as ok. So far so good. Hoping the problem is resolved.

[Jim B PEI]

What Jeff said. I've had two cars do exactly that--when nice and hot, and when the engine was at idle or when coasting around a corner in gear, the engine would die, without a kick or warning, just completely dead. 15 minutes later, after nothing when turning over the engine, it would on another try restart at first touch of the key and run fine, as long as it was on the highway getting lots of air flow. I tried ignition switch, cap, sp wires, distributor wiring, points, condenser--and finally the coil.

The second car was easier to diagnose than the first.

[Roscomacaw]

Just now looking at this thread. Yeah, I've had several vehicles suffer the fate of intermittent ignition coils - acting just as you've described. I've also encountered two Studes that had failing ignition switches that pulled the same act as well. The trick to looking for the cause between gas and ignition is how you described it being as if you'd shut the key off. Fuel shortage is gonna give a bit of diminished power and stumbling just before total shutdown. But spark - once gone - is gone. If it shuts down abruptly, that's what to look at.

[starliner62]

I hope it's fixed. If not, just drop it off in Hope Mills. Yous should be tired of that old Avanti by now!!!!

[edpjr]

I have been soooo good to this car. But it's haunted. My brother fixed the coil, installed a check valve in the gas line, and did some other things for me. When he replaced the air filters he called and said they had what looked like oil residue in them. We were both puzzled by that one. Then he detected what appeared to be a noise coming from the supercharger. When he checked, the fluid level didn't even register on the dipstick. He put 6 oz of Type F auto trans fluid in it. When last routinely checked the thing was full. It seems to be fine now. Makes no noise and runs great. But one guy told me the S/C was trashed and would have to be rebuilt before it locks up on me. Anyway, we surmised the S/C musta somehow upchucked the fluid into the air filters. I can't take mysteries like this one much longer...

I hope it's fixed. If not, just drop it off in Hope Mills. Yous should be tired of that old Avanti by now!!!!