Water temperature and stalling out

Lou1119 · #1 (**permalink**) 03-10-2014, 06:21 AM

I recently purchased a SPF replica and am having a problem. The car will fire up on the first attempt every time but after driving it short distances (4 to 5 miles) it will not maintain the idle; you have to keep the rev's in excess of 2,000 RPM's or it will stall. Once this happens it will not restart until it cools down. I have had this happen on at least 3 occasions and fortunately good Samaritans pushed me in order for me to pop the clutch and get it fired up.
The engine in the car is a 351 stroked to 427. The car will get to 90 to 110 degrees C in a short period and I feel that the water temp could be the culprit here. With similar engines what temps are you getting?
With the car acting like this I really don't want to drive it and get stranded again because it is only a matter of time that it will die uphill and leave me stuck in the middle of a road.
Thanks,

Lou

DanEC · #2 (**permalink**) 03-10-2014, 07:27 AM

Those sort of sound like the classic signs of a dying coil. They will fire your engine OK when cool but as they heat up over an interval of time and the voltabe output starts falling off. Once they cool off they will fire the engine up again until they heat up and then they shut down. But, could be several other things too.

Ron61 · #3 (**permalink**) 03-10-2014, 07:49 AM

Your water temp. could be a little high for your engine but I agree with Dan that this sounds more like a coil or some other issue related to ignition. My engines, which are racing engines, run at around 220/230 degrees F which is where they make the most power.

When it stalls and you try to start it, does the engine turn over easy? Also do you notice any roughness in it's running just before it stalls? Will it do this if you just start it and let it set and run for a little bit?

Ron

Seagull81 · #4 (**permalink**) 03-10-2014, 09:12 AM

I assume this engine has a carb. Have you checked to see fuel is coming out when the throttle is opened. Maybe vapor locked? I also assume the engine spins over fine just no start. Have you checked with the previous owner about his experiences?

lippy · #5 (**permalink**) 03-10-2014, 09:37 AM

I had a problem that wasn't completely different. Cold starts were fine, but hot starts were difficult. I *think* the problem was caused by fuel percolation. My carb has sight glasses and I could see the fuel boiling when I stopped. I installed a 0.25" phenolic spacer and it seemed to help. Could be the coil too.

madmaxx · #6 (**permalink**) 03-10-2014, 09:41 AM

This is a first!!!! I have never heard of a SPF with high coolant temps, there system appears oversized. Even in Houston at 100F my water temp is 85C.

I do not think the coolant temp is related to the stalling. I like the coil idea. If you dont want to replace maybe you can check resistance across it when it dies to identify the culprit.

WardL · #7 (**permalink**) 03-10-2014, 09:58 AM

I agree the water temps seem high as I am in the 90C before the fans come on. Do the fans kick on and run continuously when the temps are over about 90C? Why are you push starting it when it won't start. I don't think the fan temp relay is connected to the dash temp sensor meaning your dash temp gauge could be reading wrong and the fans will still kick on around 90C. I think all Cobra's should have a phenolic spacer!

Lou1119 · #8 (**permalink**) 03-10-2014, 10:37 AM

Quote:

Originally Posted by Ron61

Your water temp. could be a little high for your engine but I agree with Dan that this sounds more like a coil or some other issue related to ignition. My engines, which are racing engines, run at around 220/230 degrees F which is where they make the most power.

When it stalls and you try to start it, does the engine turn over easy? Also do you notice any roughness in it's running just before it stalls? Will it do this if you just start it and let it set and run for a little bit?

Ron

The engine is also a racing engine built by Coast high performance When it stalls the engine will not turn over. All that I get is a single clicking sound. I have not noticed any rough running before it stalls.
Typically I start it let it run at idle until the oil temp and water temp gauges start to move.

Thanks for your reply.

Lou

Lou1119 · #9 (**permalink**) 03-10-2014, 10:40 AM

Quote:

Originally Posted by Seagull81

I assume this engine has a carb. Have you checked to see fuel is coming out when the throttle is opened. Maybe vapor locked? I also assume the engine spins over fine just no start. Have you checked with the previous owner about his experiences?

The engine does not spin over, all that I get is a single clicking sound. I have spoken to the previous owner and said he has never experienced this.

Thanks,
Lou

lippy · #10 (**permalink**) 03-10-2014, 10:45 AM

Did you check your ground, battery, and starter?

Lou1119 · #11 (**permalink**) 03-10-2014, 10:46 AM

Quote:

Originally Posted by WardL

I agree the water temps seem high as I am in the 90C before the fans come on. Do the fans kick on and run continuously when the temps are over about 90C? Why are you push starting it when it won't start. I don't think the fan temp relay is connected to the dash temp sensor meaning your dash temp gauge could be reading wrong and the fans will still kick on around 90C. I think all Cobra's should have a phenolic spacer!

I am push starting it because I want to get it out of traffic lanes. The first time it happened the first car that came behind me was a driver's ed car with a student driving. I thought to myself this is not going to be good.
Thanks
Lou

Rick Parker · #12 (**permalink**) 03-10-2014, 12:15 PM

On the lines of electrical it could also be the magnetic pickup in the distributor. Heat can cause an open circuit which creates the primary side of the ignition to fail. If you have an MSD ignition box here is a check for that the next time it happens:

If you are using the 2-Pin Magnetic Pickup of the MSD to trigger the ignition, follow these steps.

1.Make sure the ignition switch is in the Off position.
2.Remove the coil wire from the distributor cap and position the terminal so it is approximately 1/2" from a good ground.
3.Disconnect the MSD Magnetic Pickup connector from the distributor.
4.Turn the ignition to the On position. DO NOT CRANK THE ENGINE.
5.With a small jumper wire, short the Green and Violet magnetic pickup wires together then pull the jumper off. Each time the short is removed a spark should jump If spark is present, the ignition is working properly, so is the coil.

Do this before it cools down to isolate the problem.

madmaxx · #13 (**permalink**) 03-10-2014, 12:59 PM

Yes there is a ground wire in the trunk from the battery to frame. It breaks at the terminal where it connects the frame. Pull up the carpet behind the battery tray and remove the terminal, its the only way to inspect. You should have noticed your amp gauge going crazy though.

Quote:

Originally Posted by lippy

Did you check your ground, battery, and starter?

Lou1119 · #14 (**permalink**) 03-10-2014, 02:09 PM

Quote:

Originally Posted by madmaxx

Yes there is a ground wire in the trunk from the battery to frame. It breaks at the terminal where it connects the frame. Pull up the carpet behind the battery tray and remove the terminal, its the only way to inspect. You should have noticed your amp gauge going crazy though.

I have noticed the amp gauge jumping at idle or even when I give it gas at a stop to keep it running. So remove the ground and do what the previous forum member recommended?

Thanks,
Lou

WardL · #15 (**permalink**) 03-10-2014, 11:11 PM

Check the battery terminal connectors, chances are you will need to replace them. The only time my SPF did not start in 4 years is because the connectors to my battery were corroded away. The starter clicking noise is classic dead battery, so if the terminal connectors are good, you probably need a new battery.

Lou1119 · #16 (**permalink**) 03-11-2014, 12:09 PM

Quote:

Originally Posted by WardL

Check the battery terminal connectors, chances are you will need to replace them. The only time my SPF did not start in 4 years is because the connectors to my battery were corroded away. The starter clicking noise is classic dead battery, so if the terminal connectors are good, you probably need a new battery.

Thanks for your response but once the car cools down the battery cranks like a champ and the car fires right up. So the battery does not seem to be the problem.

Lou

DanEC · #17 (**permalink**) 03-11-2014, 03:46 PM

Now it kind of sounds like an extreme case of too tight piston to cylinder clearances. It's hard to blelieve it would start tightening up in 4 or 5 miles but if it gets up to 100 C that fast - maybe it's possible.

Do you have the build sheet on the engine? If so, does it state the type of pistons and the piston to cylinder clearances? What compression ratio is it supposed to have?

WardL · #18 (**permalink**) 03-11-2014, 08:59 PM

The starter clicking noise is due to not enough juice getting to the starter. The piston tolerances wouldn't cause a starter clicking noise. The heat is causing a poor connection between the battery and the starter. The heat must also be causing a poor connection between the battery and the ignition system. Probably the same connection somewhere. Check your big thick battery connections in the engine compartment?

Rick Parker · #19 (**permalink**) 03-12-2014, 12:22 AM

Starting issues could be the old school Ford type starter solenoid on the firewall if it is used but that would not affect drivability after warm up. You've got a heat induced open circuit in the primary ignition system, might even be in the fuse panel. But I would check inside the distributor.

Ron61 · #20 (**permalink**) 03-12-2014, 02:44 AM

I agree with the heat causing the problem, but even if the distributor is bad, that shouldn't keep the motor from turning over. I would get a remote starter and run it where there is no traffic until it stops and then start using a VOM to check for voltage at the starter and other key points. The loose ground is sounding more and more like a possibility and seems to be one of the key causes of these cars having weird problems. It is possible the starter is shorting when hot, but I doubt that.

Ron