Engine cutting out and stalling
 

I recently got my car back after a long hiatus to have it rebuilt. The old trash engine was replaced with a Roush 427SR. Being without the car so long I could not wait to get in on the road. The engine fired right up and I decided to get the tank filled up. I drove the car to the gas station, filled it and started back home. I came to a red light, stopped and started to move in first gear and shifted into second and the engine cut out and stalled. The car restarted easily and I proceeded to move out again with the same result. Third try and the same xxxxing result. At that point I decided to get home in first gear (about 3/4 of a mile).
A few days later I decided to give it another try with the same result but on another pass I was able to get the car to perform well and could shift through the gears. However the same thing happened when I turned around on the way home.
When the car was put back together the fuel pump, fuel filter and fuel lines were replaced with new parts. The only thing that was not replaced with new components was the MSD 6AL box. My tech seems to feel that the box is the culprit. Any thoughts or suggestions?

Thanks,
Lou
My love/hate relationship with the Cobra continues.

Lou,

Warm the engine up at home to point of it cutting out again.

Then perform the MSD spark test.

MSD Ignition

This confirms whether the fault is either your 6AL box, the distributor pickup, pickup harness, or ignition coil.

Also check the carbon brush to rotor contact, and condition of all components.

Ca. Gas?
trash in fuel filter?
Fuel filter to small?

When it craps out, check the float level in the primary bowl through the site glass.

If empty, you've found your problem.

If not, try another coil. That's what they do when they start to fail.

If the engine ran well to the gas station I would suspect the lousy gas we have out here first and then check the float settings and such. And if they had just filled the tanks at the station, it will take quite a while for all of the trash in them to settle back to the bottom. I never get gas at a station when I see a tanker truck there.

Ron

I would sort of doubt a fuel delivery problem if the engine is dying like the key was turned off and the car immediately starts back up. It would usually take a bit of cranking to fill a low fuel bowl. Fuel problems usually don't cause the engine to stop like turning off the key. A trashed up filter may allow you to start out fine but will cause the engine to lean out and stutter when you start to open the throttle, but not usually die completely.

That would leave electrical. I would make sure all your connections are tight at the starter, MSD box, distributor and the ignition switch and then consider trying another coil if you can find a spare.

Lets do basics.
 

Lou1119 Lou lets see what you don't have, Fuel or Spark.
Simple test if you have a carb, Remove air filter and hit the carb linkage ONLY once to see if you have fuel going into the motor.You should see a fuel squirt going down into the motor. If not, Pour a LITTLE fuel into the carb and crank it. See if it wants to start. If yes, we have a fuel problem. Look at what pressure we have. Does the car have ANY rubber hoses on it. It is very possible that the gas has eatin the rubber and clogged the filter or the carb.
Replace or clean out carb.
If fuel is not a problem. pinch off the fuel supply line. we need to check and crank the motor without having fuel being dumped and washing out the cylinders. Fuel line or fuel pump not running, next
Simple test, crank motor see if you have oil pressure. If not you have either a stripped gear on the distributor or a broken pin for the gear to the shaft. Pull cap and see if you can rotate rotor with motor off. If yes broken pin. If you have oil pressure this check the distributor and is working to a point. make sure the rotor is spinning. If spinning good. Check cap and rotor for burn marks or center contact being complete and not broken off. Put cap back on distributor. Loosen coil wire and crank, listen and check for spark. if you have it should be bright yellow. If it's barely there, we have either a poor sign or weak coil. What kind of coil do you have and where is it located. If you have an "E" coil the mounting does not matter. Just make sure you have good power and grounds to the coil and motor. Should have a min of 2 grounds. 3 is better. Either ground straps or aux cables of 10 gauge or larger. If you have an oil filled coil, this is the orginial looking coils and it is mounted vertial on the motor, you could have burnt out the windings. Horizonal is better and off the motor is the best way to mount a coil. Spark weak, get another coil, You are going to repair a part at a time. Most guys that run MSD have double spare parts and the tools to repair on the side of the road. I have spare complete distributor, modules,(2) and coil. I burnt out caps a couple of times.
Back to repair, THIS IS VERY IMPORTANT, DON'T DO ANY TESTING WITH THE MSD SYSTEM ON. IT PRODUCTS ENOUGHT VOLTAGE TO KILL YOU OR GIVE YOU A HEART ATTACK. I HAVE BEEN ZAPPED 1 TIME. NEVER want to have that happen again. Tasted like battery acid for 3 days.:eek:
Follow the msd testing. If it's the module, send back to MSD. They will sometimes repair or replace for free. If you goto a swap meet. pick a spare up for about $100.00-$125.00. You can send it to them ahev have it checked. Same for distributor and coil. Put basic tools in a small bag to use if you need to replace them on the side of the road or call AAA.
That's about it. Make sure you are running the correct distributor gear on this motor. Bronze gear is no good. Steel, iron of polymer would be correct. Good luck Rick L.
PS I reread your story and I am thinking you have a loose ground or power wire in the car. Recheck the battery cables and connectors. Check the grounds to frame and motor. Check the ALT battery cable on the back for being tight. These thing will all cause the same problem. You said the problem happens when shifting, Motor and drive train move, think weak or loose connection. Check at starter battery terminal also. I don't know wear your power feeds come from and goto on your car. Verything tight and clean, no wiggling of wires on connectors. It might be something this simple. This would happen more when moving the car or hot driving.%/ Do this part first before going into fuel and Ignition.

Had almost the same issue, My gas cap was not venting, something to think about

Thanks for the response. How did you solve it?

Thanks,

Lou

New install with an intermittent problem that makes me think ground. Check the MSD ground. Not sure if this is still done but is there a ground strap to the engine. Engine rocks loses ground, makes it intermittent.

Good luck!

The other day my car was cutting out and wouldn't idle. When I took the float bowl and plate off, I found a tiny piece of gasket blocking the idle circuit. Put it back together and all was good............

Rick,

Your response was very good and quite in depth.
The engine was brand new from Roush and was tested by them prior to delivery. All fuel lines were replaced as was the pump and filter.
Knowing the lack of reliability of the MSD box and coil, last week we replaced both with a new digital 6AL box and coil.
The car still did the same thing but intermittently. One day it would run flawlessly, the next day it would die on me.
Initially at this go round I thought it was fuel delivery. I ran the car with the cap on and the large aluminium cap closed same result. Ran it without the cap and the large cap open, same result. Ran it without the cap and large cap closed. It ran well but still the same intermittent problem existed. I replaced the cap with one from NAPA that was recommended from a GT 40 forum. The car ran for a 1/3 of a mile and died. Took the cap off and drove it for approx. 5 miles without an issue.
Yesterday I tried it again, died. I did notice that when I tried to restart it the ammeter was showing a +25 on the gage. I Recall that it read that way on previous occasions. This morning I restarted the car and the gage after it started was reading zero no negative or positive reading. This does not sound normal with the positive charge after it dies. Your thoughts?

Thanks,
Lou

I have a friend that just bought a brand new engine from Keith Craft to go with his new Backdraft that he received last spring. Same problem in fact he had been stranded a couple of times.

After checking everything under the sun it was revealed that when his gas tank was delivered to Backdraft it still had plastic shavings in it. Those fine shavings made their way past all the filters and lodged in the needle and seats. Keith Craft sent him a brand new carb once we determined the problem.

Another thing to check is your accelerator pump on your carb. I have had that happen as well but it was usually on an older carb that had been ran quite a while. Rick Lake knows his stuff and has been down this road many more times than me as have several others. I recently had to replace my distributor cap and coil because they were fouled from arching.

I also had a similar problem and it was corrosion on the idle circuit of the metering block.

IMO a car with a fuel delivery problem isn't going to run fine one drive and totally shut down on the next one but start back up immediately. Still sounds electrical. I don't know what kind of connection blocks your wiring harness is made up with but as a precaution I would trace all the circuits between the ignition switch and ignition components to look for any pin connectors that are not fully seated in the connection block and not making full contact. Check that all grounds are good and tight. Even check out your coil wire closely and make sure it hasn't been damaged or has a poor terminal crimp. Also check connections at your ignition switch, starter and starter relay.

check your grounds

all of them

take them loose and clean all paint or corrssion before your re-install.
Lugs, studs, bolts check everything. If there is a splice look at it very close

Dwight

I agree on the grounds. Make sure there is an engine ground strap also.