I need a good diagnostician in the Sac area?

UB DRMNG · #1 (**permalink**) 06-08-2009, 01:59 PM

I have been having a problem with the Cobra and I am wondering if you guys might have a person or shop in mind that is real good at finding intermittent problems?

Going down the road it just dies. If going 50 plus it will usually fire back up before it completly stops. If in town it will usually require stopping on the side and using the starter.

Shortly before it trys to die it will occasionally have a hesitation in the power output several times.

Anyone know of a good place to take it?

Calbullet · #2 (**permalink**) 06-08-2009, 02:15 PM

Ray, give Gary Cook at GT Auto a call. He's off of Sunrise Blvd.

wanab5150 · #3 (**permalink**) 06-08-2009, 11:24 PM

Ray, try this ................

Run the car up to 50 or so gently then stand on it until it dies and just keep your foot on the gas (don't let up). See if fires and starts the (run/die) sequence over and over.......if it does then it's possibly either the fuel pump or some other fuel restriction.

Check your fuel pump pressure with a gauge (get the spec on pump first), if the pressure is OK, then place the gas hose from the fuel pump into a bucket and hit the starter and see if it maintains a stream.

I've seen diaphragm issues with both electric and manual pumps. If the diaphragm has a crack or hole in it then the car will run out of gas at a high RPM but be able to pump enough into the float bowls when the RPMs drop. The hesitation and stutter is the float bowl going dry temporarily.

This is my first guess from the couch. I've had similar symptoms and it was the coil, but my first guess would be the fuel pump, filter, or other fuel restriction. tom

jmarsey · #4 (**permalink**) 06-08-2009, 11:42 PM

I'll 2nd Gary at GT Auto.

UB DRMNG · #5 (**permalink**) 06-09-2009, 09:25 AM

I guess if we are diagnosing here it would be helpful to know what is in the car! It has a 302, EFI with Vortech Supercharger, MSD 6BTM.

During the first 30-45 minutes or so, from cold, it shows no signs of a problem. When I stand on it, it runs up to and over 100 with no signs of fuel starvation.

When it has been running long enough for the problem to appear (usually 40-60 minutes or so) it still runs great except for the occational miss or stumble or Hesitation and of course the tendency to just die unexpectedly.

I called Gary Cook, He does not have a Dyno to run the car on until it malfs so trouble shooting would be changing out parts. I was hoping to find a dyno to bring it to hot and in the puke mode so they could run it with the diagnostic equipment on it to isolate the problem.

Gary said he would start with a fuel filter, so I put on a new one yesterday. If I get a chance to drive it today we'll see what happens. The filter I took off didn't show any of the "bad" signs Gary said to look for. I hope it is this simple though!

I do appreciate any ideas you guys have. Thanks!

tcrist · #6 (**permalink**) 06-09-2009, 09:53 AM

How close is your fuel line to a heat source? Could it be getting the fuel too hot?

Terry

UB DRMNG · #7 (**permalink**) 06-09-2009, 11:49 AM

Quote:

Originally Posted by tcrist

How close is your fuel line to a heat source? Could it be getting the fuel too hot?

Terry

I need to check that. My father had a truck that would vapor lock from that very thing on a hot day pulling a grade at altitude. When this decides to poop out it almost acts like the truck did. Little to no throttle response mostly rattles a little with throttle input. Only thing it usually fires back up before you get to a complete stop if you were at speed over 45 or so. It quit on me one time 2 seconds after pulling away from a stop light and it was hard to restart until I floored the gas while cranking it, then iy lit up.

I just got the car a few weeks ago and this is my first repro cobra so I don't really know how it was built or where anything is at... Learning quickly though, unfortunately!

jhv48 · #8 (**permalink**) 06-09-2009, 12:54 PM

Boy, did I take this thread wrong!

Thought he was looking for a good Urologist!

GT390FE · #9 (**permalink**) 06-09-2009, 01:24 PM

What about plug wires, causing this problem. Danny had this backfiring running poorly problem not long ago. I think one issue was plug wires the other was a loose base plate in the elecronic distributor. Could be off base here but this sounds familiar. What injection system is on your car Mas-flow / Edelbrock ?.

UB DRMNG · #10 (**permalink**) 06-09-2009, 01:43 PM

Quote:

Originally Posted by GT390FE

What about plug wires, causing this problem. Danny had this backfiring running poorly problem not long ago. I think one issue was plug wires the other was a loose base plate in the elecronic distributor. Could be off base here but this sounds familiar. What injection system is on your car Mas-flow / Edelbrock ?.

I don't know what FI it has.

This illustrates why I would like to find a shop with a dyno to run it on until it malfunctions then the test equipment might show where the problem is or at least shot what it is not. There are so many possibilities of what it could be to just start throwing parts at. Of course it would help if I knew what all of the systems in the car were also.

maurice19 · #11 (**permalink**) 06-09-2009, 04:03 PM

Ray,

Try SVS on tower ave SAC
Maurice

UB DRMNG · #12 (**permalink**) 06-09-2009, 06:37 PM

I took the car out this afternoon and the only time it quit running was when I turned off the key! I think it is time to pull the gas tank and see if it has any more crap in it and if it does, what kind of crap it is. If it has rust scale it'l be time for a new tank. If nothing is there I'll have piece of mind.

The car still has an occasional stumble but nothing like before the new fuel filter. Maybe 5 hickups in 2.5 hours of putting around. This is the first time I have been able to go more than an hour without it dying 1-4 times!

Does anybody know what Gary Cook likes to drink? I would like to bring him a case or bottle of something to say thanks. He listened to my story and made a few recommendations, I think he got me on the right track. He didn't have to do this, but he did! He is someone I will most likely take the car to in the future.

Also, thank you to all who have helped out here! You are all top notch!

UB DRMNG · #13 (**permalink**) 06-09-2009, 10:43 PM

Quote:

Originally Posted by maurice19

Ray,

Try SVS on tower ave SAC
Maurice

Thanks,

I know Vince seems to be satisfied with them, they have worked on this car, but I spoke with them and got an uneasy feeling about them... Perhaps I called on a bad day, but you know what they say about first impressions. My impression is they don't want to work on my car.

Today I called several hot rod friends to see if they knew of a place to go to but the general concensus is don't go there! The only other places that have been reccomended are out of town.

I think I have the problem figured out. I am taking off work tomorrow and going on an extended test drive (

) to empty the gas tank I just filled so I can pull it to check the inside for debris/rust, water, etc.

I have heard that some cars have some sort of screen on the gas pickup in the tank like a pre-filter, I wonder if Mustang tanks have this?

GT390FE · #14 (**permalink**) 06-10-2009, 02:06 AM

Hi Ray,
If you have a late Model Mustang tank with the fuel pump in the tank you most likly do have a screen over your pickup in the tank. It's pretty easy to check but you still have to drop the tank most likly unless who ever built your car put in an access door in the bottom of the trunk. Might check under the trunk carpet to see.
Dan

UB DRMNG · #15 (**permalink**) 06-10-2009, 11:59 PM

There is a fuel pump in the tank and another just out side of the tank. The external pump is a little white round cylinder about 1.5" X 5 or 6". Is it normal to run an additional pump with a super charger?

Today the goal was to test drive the car and burn up some gas! The car died twice in 3.5 hours

. But that is much better than before replacing the fuel filter.

Any way my butt got sore before I got the tank empty so I dropped the tank and hooked up the internal pump connections to 12V and pumped the rest of the gas into a gas can so I could look inside for rust. To start with the pump ran fine but after several minutes it began running intermittently in an irregular patern of on off. I'm not a mechanic but aren't the pumps supposed to run all the time or at least until they reach cut off pressure? This one would stop pumping when I pinched the line off and it built up pressure, but it ran intermittently. Thinking this could be the problem I bought another pump.

While the pump was out I looked in the tank and it looked clean and shiney no rust in sight, but when I was putting the new pump in I noticed that there is a U channel shaped box like object in the bottom (baffle?) and I think the pump pick up goes in the center of it? But the strange (to me at least) thing was this box/baffle was loose. I could push it around in the bottom of the tank with a long screw driver! I am not sure but is this supposed to be secured in the tank?

What to do, What to do?

Oh, there was no access door in the trunk... that would be too easy! :-)

UB DRMNG · #16 (**permalink**) 06-11-2009, 12:09 AM

If I have to replace this tank are there other or better options than another Mustang tank? Maybe something with more range?

I see FFR offers a Fuel Cell w/22 gal capacity... way outside my budget but the extra gas would be nice for long runs!

tcrist · #17 (**permalink**) 06-11-2009, 10:34 AM

Ray,
Did you build this Cobra? If you did not build it, how long have you had it?
If you bought it, maybe the previous owner had a problem with the fuel system and added the extra fuel pump to fix it at the time.

I believe you should only need one fuel pump.

As far as that bracket in the bottom of your tank, can you see in your tank to see if it was welded in place at one time or another.

Just a couple of thoughts,

Terry

wanab5150 · #18 (**permalink**) 06-11-2009, 10:44 AM

Poor Ed and I both have 550HP Roush 427R's w/3.46 final. Sunday we both got 21 MPG through the back woods to Murphys. We also both get about 5 to 7 in town.
With a 17 gal tank, it gets more miles per tank tank my Z3 or Tahoe. (Just for reference) If you need to go 500 miles on a tank the 22 gal is for you. tom

GT390FE · #19 (**permalink**) 06-11-2009, 10:39 PM

Check Breeze for new pumps and tanks
http://www.breezeautomotive.com/

2 fuel pumps sounds a little odd you might call Vince the old owner and ask him about that, he may or maynot know that story. Baffle loose I don't think thats normal mine was not loose just had it apart a few weeks back. Not sure loose would hurt anything really but I think the Baffle is for anti-slosh in the tank. Was your fuel gauge working when you pulled the tank ?, nows the time to service that too while the tank is out. Finding a good used late model Mustang gas tank if you want to replace it should not be too hard. Check the wrecking yards on south Sunrise. The FFR tank is the only one I've seen that would bolt right in. Some sort of fuel cell is another option but mods will probably be needed.

Calbullet · #20 (**permalink**) 06-11-2009, 10:47 PM

Ray, whatever you do, be careful working on your tank. good ventilation is a must, gas fumes are dangerous, just needs one little spark.