Flashing - then steady CEL


33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
Had a real nice early season drive with a couple other local GT guys (thanks Jason and Chris!). Had some spirited moments..

Towards the end of our drive - the CEL started flashing - . Drove slowly and in about 5 minutes went out.

On the way home (car was shut down for about 20 minutes) - driving 55MPH - the CEL came on steady.

Did a scan - and came up with codes:

P1000 - On Board Diagnostic Readiness Test not complete

P0300 - Random Misfire detected

P0302 - Cylinder 2 misfire detected

P0303 - Cylinder 3 misfire detected.

Per previous posts (last fall) - there is a lot of boost with the 2.5" pulley - and in May - Torrie is coming up to do a tune.

This car has 2.5" pulley
Ford long tube headers
Ford (borla) muffler.

Any thoughts appreciated- thanks all!
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
I'd recommend looking at the sparkplugs in cylinders 2 and 3 and go from there. What tune is in the car now?
 

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
Its the tune that came with the car... apparently done by the dealer shortly after the car was bought in 2005.. I have the original SCT tuner (which apparently is not useful anymore). The tune was apparently done when the car had 700 miles - it now has 2200.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
It is more typical to see a 2.75" aftermarket pulley on a GT than a 2.5". Regardless, it is IMPERATIVE that the car has a tune that will it compensate for the additional boost provided by a faster-spinning SC. Let it be a lesson to others - if you are buying a used GT that has been modified (pulley, Whipple, Turbos, etc) it is in YOUR best interest to know who did the tune and to have confidence that the tune was done correctly.

33Bravo - I think I'd reiterate my recommendations to check spark plugs in cylinders 2 and 3..... and cross your fingers that everything is OK. If anything is suspicious about the sparkplugs, I'd use a borescope to see what the cylinder/pistons look like.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
It is more typical to see a 2.75" aftermarket pulley on a GT than a 2.5". Regardless, it is IMPERATIVE that the car has a tune that will it compensate for the additional boost provided by a faster-spinning SC. Let it be a lesson to others - if you are buying a used GT that has been modified (pulley, Whipple, Turbos, etc) it is in YOUR best interest to know who did the tune and to have confidence that the tune was done correctly.

33Bravo - I think I'd reiterate my recommendations to check spark plugs in cylinders 2 and 3..... and cross your fingers that everything is OK. If anything is suspicious about the sparkplugs, I'd use a borescope to see what the cylinder/pistons look like.

:agree:

Excellent advise.
 

Not 4N

Tungsten GT Owner
Mark IV Lifetime
Apr 5, 2006
887
Calgary AB
I had this code on one cylinder and it was the coil pack. Cleared the code and swapped packs from one cylinder to another and the fault code followed the pack to the new cylinder.
Can't say it is the same as you have two acting up at the same time but worth a check.

Trent
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
I had this code on one cylinder and it was the coil pack. Cleared the code and swapped packs from one cylinder to another and the fault code followed the pack to the new cylinder.
Can't say it is the same as you have two acting up at the same time but worth a check.

Trent

That is a little troubling having two cylinders fail makes it unlikely to be coils, but it could be as simple as the plugs are all old and worn. A simple start would be to yank them all and replace. Compare the plugs from each hole and look any anomalies.
 

Fubar

Totally ****** Up
Mark II Lifetime
Le Mans 2010 Supporter
Aug 2, 2006
3,979
Dallas, TX
I had a few codes like that turn on for me all at once. It's turned out to be minor... Can't remember what the issue was. I'll search my old posts later.
 

Fubar

Totally ****** Up
Mark II Lifetime
Le Mans 2010 Supporter
Aug 2, 2006
3,979
Dallas, TX
I looked at my thread, we used a slightly boosted voltage to the coil. Initially we thought the extra voltage was making the ecu mad, but in the end I came to suspect it was the extra heat caused by the voltage. You might check for a boosted spark box on this car. If you find there is one, just disconnect the sensor that activates it. If there is no such box, then look for coil interference or loose coil covers.
 

paul b

GT Owner
Nov 2, 2006
810
Flashing cel is telling you of the misfire, and can cause catalytic converter damage. I had a similar problem with cylinder#1. Swapped coils from 1 to 2 and the problem hasn"t come back. The best I could come up with was the coil connector wasn't making a good connection and connecting and re connecting fixed the problem. After pulling your plugs and looking at them, perhaps a compression test would help since the failure came up on adjoining cylinders.
 

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
I'll check the plugs -and the coils - hopefully it is one of those.

Being the not-so-smart guy that I am - after running the initial scan - I left the keys in and the ignition on. So of course when I tried to open the door today - it would not because the battery is dead. Got the Cooltech charger plugged in.

Duh
 

paul b

GT Owner
Nov 2, 2006
810
You can open the door with your second key, if you have one.
 

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
You can open the door with your second key, if you have one.

Yes. Thanks. I was able to get the door open and confirm the initial dumb-key mistake.

I'll let it charge for a few hours to see if I f'uped the battery.
 

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
Flashing cel is telling you of the misfire, and can cause catalytic converter damage. I had a similar problem with cylinder#1. Swapped coils from 1 to 2 and the problem hasn"t come back. The best I could come up with was the coil connector wasn't making a good connection and connecting and re connecting fixed the problem. After pulling your plugs and looking at them, perhaps a compression test would help since the failure came up on adjoining cylinders.

Appreciate information on the catalytic converter damage. In my case - I think this is unlikely - as the converters are on my garage floor :) (I have the Ford long tube headers).

Thanks!
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Yes. Thanks. I was able to get the door open and confirm the initial dumb-key mistake.

I'll let it charge for a few hours to see if I f'uped the battery.

The Cooltech is a trickle/maintenance charger it will take 1 to 2 days to revive a completely deal battery.
 

Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,135
Florida/North Jersey
.....maybe even longer with our OEM Optima battery. Remember, they like a high current recharge from dead. Not possible from a maintenance charger.

Howard
 

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
688
Minneapolis, MN
It is more typical to see a 2.75" aftermarket pulley on a GT than a 2.5". Regardless, it is IMPERATIVE that the car has a tune that will it compensate for the additional boost provided by a faster-spinning SC. Let it be a lesson to others - if you are buying a used GT that has been modified (pulley, Whipple, Turbos, etc) it is in YOUR best interest to know who did the tune and to have confidence that the tune was done correctly.

33Bravo - I think I'd reiterate my recommendations to check spark plugs in cylinders 2 and 3..... and cross your fingers that everything is OK. If anything is suspicious about the sparkplugs, I'd use a borescope to see what the cylinder/pistons look like.

To cut to the chase - I got lucky.

The SVT guy saw a fried plug from detonation. We replaced the plugs - and ran a borescope. Fortunately it appears everything is OK.

Until Torrie runs his tune - I believe I have a couple of options. The easiest one is to drive easy (ok thats kind of hard in a GT). It was also suggested that since the tune on my car (and the 18psi boost) appear to be for racing fuel - I can run racing fuel till the tune. Fortunately there is a station close to my house that sells 110 racing fuel. Since there are no cats - I can't wreck them. Maybe f'up an O2 sensor though.

Is anyone running racing fuel - and more specifically what strategies have you used to get the bigger nozzle into the smaller GT fuel inlet (are there adapters? Funnels?)
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Whew! Glad it was an easy one.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
I believe I have a couple of options.

Sorry, no, you would be wrong. Racing fuel would help - but it is hardly a solution and you risk additional damage. I would have bet money on what you found with the sparkplugs based on your description of the pulley and unknown (if any) tune in the engine. You are indeed lucky. My suggestion is that you contact Torrie and he can set you up with a tune "out of the box" and then he could optimize once he is there.
 

tmcphail

GT Owner/Vendor
Mark IV Lifetime
Apr 24, 2006
4,102
St Augustine, Florida
I think the overall best course of action is to not beat on the vehicle until I get up there. Knock could exist from over advance / net manifold pressure or raw lack of WOT fueling. Race gas will only cover the gap if the sole event is too much advance for the current octane fuel used. If its leaning out at WOT race gas won't save the day here.