2001 Cobra Crank No Start

[67 cdime]

Hey guys. Long story short, I bought a 2001 Cobra convertible. Car has been sitting 4-5 years… flat bedded it home and the fun began.

Changed the fuel pump as it was getting voltage but not priming. Drained tank and fresh 93 octane. Still no start. Verified 50 psi at shrader valve at fuel line so good there. Pulled a coil and had the son crank, verified voltage pulse there. All fuses test good. All gauges and everything work. OBD2 port connects to PCM and I cleared some fuel pump related codes. Ran engineering test and only thing non fuel related is an open starter circuit. Clearly not a problem as it cranks.

I have not ran a compression test yet. I have checked the crank sensor and I’m reading resistance across the sensor and reading the correct voltage on the harness. Cam position sensor looks ok but unsure how to test it. I did find a mouse chewed wire that has 12v in the engine harness on the driver side. Corrected that and still no go.

I’m googled out and unsure where to test now. Help lol.

 

[67 cdime]

Hey guys. Long story short, I bought a 2001 Cobra convertible. Car has been sitting 4-5 years… flat bedded it home and the fun began.

Changed the fuel pump as it was getting voltage but not priming. Drained tank and fresh 93 octane. Still no start. Verified 50 psi at shrader valve at fuel line so good there. Pulled a coil and had the son crank, verified voltage pulse there. All fuses test good. All gauges and everything work. OBD2 port connects to PCM and I cleared some fuel pump related codes. Ran engineering test and only thing non fuel related is an open starter circuit. Clearly not a problem as it cranks.

I have not ran a compression test yet. I have checked the crank sensor and I’m reading resistance across the sensor and reading the correct voltage on the harness. Cam position sensor looks ok but unsure how to test it. I did find a mouse chewed wire that has 12v in the engine harness on the driver side. Corrected that and still no go.

I’m googled out and unsure where to test now. Help lol.

 

[01yellercobra]

You should only have 40psi at the rail. Are the plugs wet? What is the theft light doing when you crank it?

 

[67 cdime]

Theft light does the normal flash then goes off. It is not on while cranking.


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[67 cdime]

PATS usually cuts fuel or spark and I have both so I assumed it’s good.


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[DSG2003Mach1]

PATS usually cuts fuel or spark and I have both so I assumed it’s good.


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i believe on that one itll kill power to the pump - if key forward the pump primes (sounds like it does) then parts isnt stepping in.

damn, sounds like you've run this down pretty thoroughly. Not sure what might wrong at this point

 

[67 cdime]

Like I said, I haven’t done a compression test. But even with low compression on every cylinder (highly unlikely) it would hit. Then what are the chances that every single plug is dead and won’t hit.

I have tried a shot or two of starting fluid with the pedal to the floor cranking and it won’t hit.

I’m at a loss in where to check next. Compression I guess.


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[DSG2003Mach1]

How’d you test spark?

Don’t theee cars apply ground to fire it?

 

[67 cdime]

I used a volt/ohm meter. I was grounded to the battery and the positive lead to coil plug. I watched the voltage pulse as my son cranked. Unsure if this is correct way to test.


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[01yellercobra]

How’d you test spark?

Don’t theee cars apply ground to fire it?

Yes.

I used a volt/ohm meter. I was grounded to the battery and the positive lead to coil plug. I watched the voltage pulse as my son cranked. Unsure if this is correct way to test.


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Better way is either get a spark tester or ground a plug and watch for the spark. Pull the plugs. If they're wet then you have fuel and no spark. If not then you probably have no fuel.

 

[67 cdime]

Yes.

Better way is either get a spark tester or ground a plug and watch for the spark. Pull the plugs. If they're wet then you have fuel and no spark. If not then you probably have no fuel.

I will pull the plugs tomorrow while doing a compression test. So even with fuel pressure at the rail, I still could not be getting fuel at the injectors I suppose?


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[01yellercobra]

If the injectors aren't firing the pressure at the rail won't matter.

Odd thing, check the TPS. Make sure it's moving correctly. Maybe it's stuck and making the ECU think the pedal is on the floor.

 

[67 cdime]

If the injectors aren't firing the pressure at the rail won't matter.

Odd thing, check the TPS. Make sure it's moving correctly. Maybe it's stuck and making the ECU think the pedal is on the floor.

I’ll check it as well. Anyway to test its voltage/resistance to verify all is well? Also, how would I test the cam position sensor?

What sensors would cause a non start issue? If I have the presumed spark and fuel, all points to a sensor or ground. I’ve racked my brain looking and searching. I thought bad ground but EVERYTHING works other than starting.


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[01yellercobra]

I think at this point you're assuming you have fuel and spark. You can't check spark through a DMM as they always have 12vdc applied and the ECU grounds them to fire. It's the same with the injectors. Really the easiest way to check them is to get a solenoid light and plug into one or two injectoe and COP plugs and see if it flashes.

For the TPS I'd hook up your DMM through the back of the plug. I use sewing pins to stick into the wires. I think it's the top and bottom wires. If you have 5vdc with the throttle closed that's the power wire. Switch to the other wire. It should have about 1vdc with the throttle closed. Then it should smoothly move to 5vdc as you open the throttle. If you have 5vdc on both wires with the throttle closed then you found your problem. The ECU thinks it's at WOT and is shutting off the injectors.

The main sensors that would cause no start are the crank and cam sensors. It needs those to get an RPM reading and know when to fire the ignition. But if either were bad you should get a code.

Do you know if the engine was removed and rebuilt?

 

[67 cdime]

I don’t know any history of the car. Guy that I bought it off of wasn’t really a car guy. He said he drive it up to the point that he lost his license and parked it. Set in the same spot for 4-5 years. He at some point did wreck it as he told me had to replace the front bumper but couldn’t get a cobra bumper like it had.

I will test the TPS. Thanks for the explanation.

Back to the spark, when I tested it, I was on the female portion of the coil plug that goes over the spark plug. With DMM grounded to battery, I could see the voltage pulse on and off while the engine was cranked. Does that not verify spark?

I do need to test voltage at the injectors. I will need to grab a spark checker. I have a cheap continuity light but I don’t think that will do it.


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[67 cdime]

Tested TPS. Bottom wire on plug test 5v. Middle wire tests 1v and sweeps up to 5v while opening throttle body.

Went ahead and pulled cylinder 5 plug as it’s the easiest to get to. It was wet with fuel. Tested compression, as well. Test 175 ish.

So with that information, pretty sure I am getting fuel. And as stated above, even though I’m not testing spark with a spark light, I’m pretty sure I’m getting a spark pulse.

What next? What am I missing.


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[DSG2003Mach1]

plugs are wet and isn't hitting

you sprayed starter fluid and still not hitting

I can't see how this isnt a lack of spark. Even if it was somehow sparking at the wrong time you'd think i would at least backfire with a cylinder full of fuel

do you have any idea what the damaged wires were that you repaired?

 

[Chipnrail]

get one of these and test each coil for spark then you'd know for sure

 

[67 cdime]

All signs point to spark it seems. With the plugs wet, that tells me the injectors are pulsing fuel.

No idea on the wire that I repaired. I took the loom off from the CMPS all the way back to cylinder 8 injector as that was where the damaged wire was. It’s an odd wire that slack just seems to come up that loom and disappear behind the engine. It’s a GREEN wire with a WHITE strip. I tested keyed 12v on one side and no voltage on the other. At first I thought it was 2 different wires going up the harness. I have struggled to find any wiring diagrams to figure out what the wire is.


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[67 cdime]

Went and unhooked the Light Green/white strip wire that I had repaired. No change. The side without voltage looks like it runs over to the plug that runs inside the car to the PCM. Unsure where it’s getting its voltage.

Decided to make everything normal minus connecting the above mentioned wire and try to run codes. With OBD2 no codes since I erased them. With engineering/test reading only DTC9356. What does that 9356 point to?


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