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I was coming back from the pic n pull (my new hangout spot ) and the engine just shut off without warning, I thought oh man the timing belt snapped AGAIN but I had just put a good brand new belt on so it cant be. I lift up the hood and nothing looks out of the norm I even look under the car for oil spewing out thinking maybe the engine blew and nothing. I even pulled the timing cover off to look at the belt and all was fine. Meanwhile 1000mph traffic is whizzing an inch away from my car but as much times as I have been stranded im used to it by now Anyway I get back in and try the key and the car fires right up

So I drive off. About 5 minutes later the same issue. A tow truck arrives that was just passing by and I find out my car is too low I would have to wait for the flatbed truck to arrive. I get in and try the key for shits and giggles and it fires up again I wait with the tow dude for about 10 minutes with the car idling and all seems grand. So i tell the guy ill "nurse" the car home.

About a mile down the road the car stumbles a bit and back fires but doesnt shut off. It just keeps truckin home......

So a few days pass and It starts up with no issues. I drive a few miles down the road and it shuts off in the middle of the road. I get it started and crazy enough im in from of autozone.

I have a HEI and External coil on it for about 2 years now.

I thought maybe the coil was bad so I used a extra I had. No luck. I then went and bought a new one at autozone. No luck.

I try the extra HEI i had with no luck. I put the old one in and it fires up then shuts of 5 minutes later. I buy a brand new HEI from autozone and the car fires up for a second then shuts off. I put the old one on and no luck.

Im at a loss. I dont think timing belt because it fires up here and there. Would a Vac leak cause the car to run sometimes then shut off at 50mph?

Maybe the crank sensor thats in the disty be the problem? Would that really cause it to not fire?

If i dont get this issue resolved by the end of the week I may have to do a classic part out. I need a car that wont break down on me for awhile. Since I have had the car my wife and I have been stranded at least 10 times

Dad says air bubble in fuel line

it sounds like a bad connection to me. maybe a wire has come loose or a crimp has failed. i'd be on the hunt for a loose electrical connection. my bet is definetly electrical.

mx3matt wrote:it sounds like a bad connection to me. maybe a wire has come loose or a crimp has failed. i'd be on the hunt for a loose electrical connection. my bet is definetly electrical.

+1

Crank sensor in the distributor could cause this problem... Or a bad connection... The fact that its time based tells me most likely the crank sensor in the distributor..

Not to argue about the crank sensor but members here have used newer disties that have no crank sensor and other than longer cranking times to start the engine once running there were no issues. Sounds like a loose wire. I've known crank sensors that had moisture issues and would quit when it went below freezing. How much fuel is in your tank, if it's low your fuel pump could be packing it in but I doubt that but it is a consideration. Finally, have you done anything to your car lately? Some thing you did may of caused this. Good Luck.

Daninski wrote:Not to argue about the crank sensor but members here have used newer disties that have no crank sensor and other than longer cranking times to start the engine once running there were no issues.

This is the second time I have heard about this kind of thing lately.... If its not the one in the dizzy, then it'll be the one down on the crank shaft... You could try disconnecting the crank sensor on the crank shaft... See what happens and how the car acts... After that you could try cutting the signal wire for the crank sensor in the distributor and see how the car acts... If you do cut the wire make sure its in an easy location to splice back together later..

My old DE set up seemed to use the Dizzy crank sensor as its main input for spark control.. but there has been mention that goes against that... My old DE set up would run with the crank sensor on the crank shaft disconnected, but not the one in the distributor.. I wish I still had a DE to play around with it some more..

Dragon1212 wrote:Dad says air bubble in fuel line

Hmm how would I check for that?

MrMazda92 wrote:

mx3matt wrote:it sounds like a bad connection to me. maybe a wire has come loose or a crimp has failed. i'd be on the hunt for a loose electrical connection. my bet is definetly electrical.

+1

Ill redo my HEI and external coil wiring and check around the harness tomorrow just to be sure

crazycanadian wrote:Crank sensor in the distributor could cause this problem... Or a bad connection... The fact that its time based tells me most likely the crank sensor in the distributor..

I thought the crank sensor as well and changed it out with a new spare one but had no luck.

Daninski wrote:Not to argue about the crank sensor but members here have used newer disties that have no crank sensor and other than longer cranking times to start the engine once running there were no issues. Sounds like a loose wire. I've known crank sensors that had moisture issues and would quit when it went below freezing. How much fuel is in your tank, if it's low your fuel pump could be packing it in but I doubt that but it is a consideration. Finally, have you done anything to your car lately? Some thing you did may of caused this. Good Luck.

a google search brought up a fuel pump as well. I have had a quarter of a tank and ran it a tad low. I was on my way to smog the car and was about to put 2 bottles of ISO heet in the tank.......(its a cali smog thing)

I smell alot of gas while im cranking though so I was sure the injectors are getting fuel I cant remember If its my MX6 that had a fuel pump that clicked when you turn the key to position 2 or is it the MX3.....


And I actually havent done anything mechanical since i got off the boat from germany I know the ECU was throwing a o2 sensor code but it would drive normal and the light came on during highway driving id give it a tad bit throttle and the light would go off. I have new front and o2 sensors waiting for my ZE swap but at this rate I wont make it to washington

crazycanadian wrote:

Daninski wrote:Not to argue about the crank sensor but members here have used newer disties that have no crank sensor and other than longer cranking times to start the engine once running there were no issues.

This is the second time I have heard about this kind of thing lately.... If its not the one in the dizzy, then it'll be the one down on the crank shaft... You could try disconnecting the crank sensor on the crank shaft... See what happens and how the car acts... After that you could try cutting the signal wire for the crank sensor in the distributor and see how the car acts... If you do cut the wire make sure its in an easy location to splice back together later..

My old DE set up seemed to use the Dizzy crank sensor as its main input for spark control.. but there has been mention that goes against that... My old DE set up would run with the crank sensor on the crank shaft disconnected, but not the one in the distributor.. I wish I still had a DE to play around with it some more..

This I will try as well although I have replaced the original crank sensor with a newer one about a year ago just cause I had one laying around

thank you everyone for the responses. Thats why im sooo happy that this site exists

My original distributor did that, your ignitor (which is inside distributor) went out. You need another disty.

mitmaks wrote:My original distributor did that, your ignitor (which is inside distributor) went out. You need another disty.

He has the HEI mod and external coil.. This eliminates the ignitor and coil thats inside the distributor..

Try for the obvious like people have said and maybe while the car is running, have a tug of some of the HEI wires. See if it causes any reactions. Hopefully it's something simple like the HEI wiring.

Other than that, one very odd problem I encountered once upon a time was forgetting one little ground wire that went to the intake manifold near the back of the engine. If it's loose or you played with the IM recently maybe just check that it's all good.

Loose ground is a real possibility. I had my engine out last summer and reinstalled it, which I have done many times and the main ground from the frame to the transmission case was loose and and totally dead. after hours of searching through the fuse box and the wire harness...I jiggled that ground wire and the car started right up.

mitmaks wrote:My original distributor did that, your ignitor (which is inside distributor) went out. You need another disty.

+1

I got a PM to try the MAF and it started after I switched it out...weird

Thanks everyone for all the reply´s I shook my HEI wiring aslo after the car stayed on for more then 10 minutes and the car stuttered a bit so im going to redo that as well it is looking a little crusty anyway so I'm going to redo it all.