The engine cuts out above 4,000 rpm when being pushed hard Options

[shag]

When the engine is just cruising along and I am in no hurry the car runs fine. When I have the accelerator floored and am taking the engine to the maximum rpm's it begins to cut out at approximately 4,000 rpm. This had happened twice before and I changed the fuel filter, which was extremely clogged, and that fixed the problem. This past winter I removed the fuel tank and had it cleaned out and coated with some kind of reddish substance that seemed great. When I replaced the fuel tank I installed a tubular screen about 4 inches long inside the tank, a new fuel filter between the fuel tank and the fuel pump and replaced the original fuel filter which is near the right rear wheel. I thought I had done more than enough to prevent this from happening again especially since I am preparing the car for Octeenerfest. Wrong again! The car started cutting out again at high rpm's just like before. This time I took the car to Derrick Sweger, who worked for Steve Lindell for many years and has rightfully inherited his business, though is not operating yet was kind enough to lend me a hand. He replace the filter near the rear wheel and then he started on the front filter. The filter on the front was a style that has the clear plastic body around the paper like insides and it looked like it did when I installed it. It was the fuel line that had a sharp bend in it that we thought was causing the problem. Derrick had a 90 degree piece of tubing that took care of the problem. He told me to call him with the results. Approximitely 3 miles down the road I floored the pedal and the exact same problem prevailed. So now I would like to certainly have this fixed before Octeenerfest. What do you guys think is the problem?

[cgnj]

I think the problem is that you didn't provide enough information to get a meaningful answer. I think a good start woold be telling us if the car is FI or carbed. If FI is it l-jet or d-jet.

[mate914]

I’m pretty sure shag‘s car is a 2.0 FI stock

[shag]

Sorry gentlemen, Matt is correct. The engine is a 1973 2.0 with stock FI. I talked with a couple of guys this morning at the swap meet at Ski Round Top who could only think that it might be the fuel pump. I know a few years ago Bob Hill and I installed a fuel pressure indicator on the car and took it for a drive and at that time it was ok. We are going to check that again. Another gentleman suggested the MPS may be faulty? I don't know how to check one but I believe Bob does.

[emerygt350]

Doubtful on the mps.

Original dizzy?

[GregAmy]

Is it throttle position related or RPM?

Is it breaking ignition wise or total car power? Is the tach fluctuating during this? Fuel pressure is a good check to see if it's flat-lining and not keeping up (pump? fuel pressure regulator?)

TPS?
Disty needs oiling?

Needz moar info

[emerygt350]

Is it throttle position related or RPM?

Is it breaking ignition wise or total car power? Is the tach fluctuating during this? Fuel pressure is a good check to see if it's flat-lining and not keeping up (pump? fuel pressure regulator?)

TPS?
Disty needs oiling?

Needz moar info

I am suspecting stuck weights if it isn't fuel. No advance.

[Dave_Darling]

Not sure a lack of advance would cause the engine to cut out, though.

I wonder if it feels like a rev-limiter cut, where the engine will rev and cut several times per second if you keep the throttle floored? Or if the power just drops to where the doesn't want to accelerate much?

--DD

[shag]

I would like to thank you for your replies. My reply to your replies is:

Emery: My distributor was change out with ( I believe ) what is called an electronic distributor years ago. All I really know is that there are no points, condenser etc. The engine has preformed very well through the years with it.
I am not familiar with term "stuck weights". If you could explain what that means I would appreciate it.

GregAmy: I don't think the problem is with the throttle or RPM it happens only when the engine is floored from about 2,000 RPM. I (currently) am not sure but I don't think the tachometer is doing anything crazy. But I will certainly check. I need to check the fuel pressure. To do that I have to wait for my friend Bob, who owns a guage, to help.

Dave Darling: I am not sure but it seems to me that it is a lack of fuel causing the engine to cut out? I will certainly let you all know when this is fixed.


Meanwhile if you have any suggestions they would certainly be appreciated.

Thanks to all,
John

[emerygt350]

I wonder if you have a 123 or some other kind of distributor. If it is 123 there are no weights. On a mechanical distributor weights get thrown out through centrifugal force and that advanced your timing. Without that advance your engine can do something like it seems might be happening.

This only occurs under load?

[shag]

Emery, It is not a 123, but it is a type that doesn't have the old points and condenser. I have never had any problem with it for the last in the last 10 years so that could be it! I will check it out tomorrow. the only problem is that it is a distributor and all I am familiar with are the old type. I am not sure what I will be looking for but I've got to start somewhere.

[emerygt350]

Does it have vacuum advance? A can attached to it?

[GregAmy]

I am not familiar with term "stuck weights". If you could explain what that means I would appreciate it.

Sounds like you have a Pertronix (or similar) electronic points insert in the distributor.

The stock disty has internal mechanical weights that swing out as RPM rises, advancing the ignition timing. If these weights get stuck (light rust) and do not advance, then the car feels like it's not making power. It doesn't "cut out" like an ignition miss it just won't accelerate as you'd expect it to.

A widely overlooked maintenance item to avoid this is to lightly oil the weights. To do this, you'll remove the distributor cap and rotor and drop into the rotor shaft a couple drops of light oil, like 3-in-1. Even a thin motor oil would do. If you think the weights may be stuck/rusted, then a light penetrating oil such as PB Blaster or WD-40 should free them up and then follow up with some light oil. Don't overdo it, "a little dab'll do ya" (wow, that's an oldie).

The car originally came with a small foam-ish filter in top of the shaft to keep dust and dirt out, but that may be gone. If yours is there you can just drop in the oil on top of it, it'll find its way down. Dipping in a couple drops each year should keep that from happening again.

Try it, see what happens. - GA

[shag]

Emery: I am not sure but I will find out tomorrow. Thanks for the advice I will let you know.

GregAmy: I will do that tomorrow and you will know then too.

Thanks to both of you, I really appreciate the help.