Engine Cuts out at High Rpms

If you have a way to check O2 you can find out pretty quickly if it is going lean from say inadequate fuel pressure. If it is it can be very very bad for the engine to go lean at high rpm.

Could be a bunch of things, but it does sound fuel related. Sounds like it is running out of gas, so to speak... And as mentioned, running lean can do bad things.

I would start with the fuel filter but you say you've looked at that. How's your fuel pump?

if the tach is dropping to zero quickly then it is ignition related.
check things like 12+ volts AT the ign box or dizzy or coil.
if it was fuel it would cut out, but the tacho would not sharply drop.
does it do it under load ? when driving ? or in nuetral as well ?
check the float levels.

Just went out to the garage and rev the engine past 5000 for a split second(scary and loud!)..I watched the tack...and sure enough, as the needle raced past 5k, it dropped off quickly back to zero...so whether on a load driving..or reving in neutral..its cutting out. I think its ignition too at this point. This is a MSD distributor with a built in module..no external box.

Double check with the experts but I don't think that you need the resistors with the electronic ignition. Also if your electric choke is being powered off of the coil, it will act as a "rev limiter" limiting your ignitions RPM range. I agree with V8Capri that since the problem is a "cut off", it is ignition related. A fuel problem will probably cause sputtering and surging prior to cutting out.

...It sounds to Me as if You have a 'Built-In' Rev Limiter, set at 5000 RPM; and it's Working!...

is it a genuine MSD dizzy ? do you have a part number ?
also check the 12 volts at the red wire on the dizzy ?or on the coil .
I know it is hard to do !! but may be well worth it !
if it was fuel it wouldn't do it in nuetral, only under load.

Get yourself the wiring diagrams for your distributor. I agree with 4NFORD that the resistors should not be in the circuit. Also, check for 12v as stated. Do you have an electric choke? Make sure it's not tapped into the ignition circuit.
Will

quote:

Originally posted by MARLIN JACK:
...It sounds to Me as if You have a 'Built-In' Rev Limiter, set at 5000 RPM; and it's Working!...

I have to agree with Marlin here. That's what it sounds like, but does it have an ADJUSTABLE rpm limit?

There are many here that love the MSD components but I am not one of them. They are full of these gremlin type problems that are next to impossible to diagnose.

If you ever decide to give up with the MSD, put in a Motorcraft ignition. It will save a lot of grief and the parts are available anywhere. Where you going to get MSD parts in the middle of the Aussie Outback hey matie?

I thought the newer rev limiters only removed a "selective" amount of spark pulses. That way you didnt have the chance of backfire when the engine did reach its set limit????
Jeff

I think that the wording is that it shorts out every other plug firing. Still it does sound suspiciously like an rpm limiter.

He doesn't have a lean fuel problem otherwise it would backfire. More like a firecracker going off. That's what is dangerous. That lean explosion is untimed and will put a hole right through a piston.

He needs to read the instructions on the MSD unit and inquire with the MSD tech people. Unfortunately they are about as usefull as tits on a bull. That company is such a piece of shit it should be banned.

I have a pile of MSD components that I keep as a reminder to myself at how stupid I am. Their stuff is GARBAGE!

I found the problem. I went to the MSD trouble shooting website. I found a similar problem with a customer of theirs. The response was no ballast resistor should be used with their plug and play distributor. As I said..someone had put two resistors in series feeding the coil!??##!!..why???....So I just simply did away with that, and fed the 12v to the coil direct. Bingo.......runs like crazy again..no cut out at all. I use to have a mallory unilite...it left me on the side of the road one day. After installing the MSD..everything seemed fine. Maybe the unilite needed the resistors?...I don't know.
Anyway..its bitchen now...Thanks for the feed back guys.

quote:

Maybe the unilite needed the resistors?

The Mallory Unilite requires a ballast resistor. According to Dennis Quella, it needs it in addition to the existing resistor mounted to the back side of the firewall.