Cobra Troubleshooting Time!

[fordguy_1997]

Hey all,

I finally got my Cobra reassembled and tried to turn it over for the first time. I ran into a few problems so I’ll list them all here and kind of go from there.

I tried to crank the car. It would fire up but immediately die until I unplugged the MAF. Once I did that the car would crank and start and hold it. I kept it unplugged and it’s on stands so I didn’t go past idle but the car ran, got to temp, fans kicked on, etc.

I had 4 codes pop up - P0174 (system too lean bank 2), P1115 (IAT2 Circuit High Input), P0108 (Manifold Absolute Pressure (BP sensor high) and P0171 (system too lean bank 1).

I’m not concerned about the lean readings as I intend to take it to a dyno and address injectors at a minimum, but the other two codes do concern me. I unplugged the sensor at the driver side rear of the blower as I believe that is the sensor where the fault occurs, and no change. I verified every sensor being plugged in so that’s not a concern.

Car data was as follows:

ECT: 194
Spark Adv: 34.0
IAT: 55*F
MAF: 0*F (unplugged)
TPS: 18%
Fuel Pressure: 39.1 PSI

A/C works fine, heat blew hot and no significant drop in the coolant level once filled. The car would flutter with heat on windshield and footwell between 1000 and 750, but once I cut that setting it would go steady. Also - I noticed the intercooler pump wasn’t running. I stupidly forgot to fill the intercooler tank prior to initial startup, and the car got about 50-60% of operating temp before it was filled, but temps didn’t get significant enough for it to become catastrophic. But pulled the intercooler tank - not any signs of swirl and the heat exchanger was cold as ice even after the car got to operating temp. Alternator V/R had some lights on it that were weird. Orange one was in and the green one was dim when the car wasn’t running but the key was in the on position. Verified the tightness and quality of connections and they seemed ok.

I don’t really know where to go from here and would like some input as to where I have to start. I consider getting it firing on all 8 a win, but I have a ways to go before the car is tunable. Any input would be greatly appreciated. I’ll also include pictures of my vacuum lines and whatnot so everyone can see where I have things connected as well as my voltage regulator.

Thank you all very much!

 

[03' White Snake]

That's good news she's running.

Check the 02's are plugged in. Check for exhaust leaks too. This would cause lean conditions.

The intercooler pump only kicks on when it is up to temp. You can jump it in the little black fuse box on the passenger side fender with a jumper wire. It is the 2 connections parallel to the front of the car. (fender towards engine) This will tell you if the pump is good or not.

 

[FrankShelby]

Awesome work!

 

[hotcobra03]

2 codes on the same sensor.. tmap

p108/p1115

check the connection is fully on and clip doesnt just pull off
..and for damange wires..
pinched wires

 

[hotcobra03]

P0108 - BARO/MAP Sensor High Voltage Detected​

Sensor operating voltage is greater than 5.0 volts (VREF), as a result it failed above maximum allowable calibrated parameter.​

VREF shorted to VWPR BARO/MAP signal shorted to VPWR Damaged BARO/MAP sensor Damaged PCM

VREF should be less than 6.0 volts. PID reading is in frequency/Volts​

 

[hotcobra03]

P1115 - Intake Air Temperature 2 Circuit High Input​

Indicates the sensor signal is greater than Self-Test maximum. The IAT2 sensor maximum is 4.6 volts.​

Open circuit in harness Sensor signal short to power Improper harness connection Damaged sensor Damaged PCM

Monitor IAT2 PID. Typical IAT2 temperature should be greater than IAT1. Refer to Reference Values: Reference Values for ranges.​

 

[hotcobra03]

Adobe Acrobat

acrobat.adobe.com

vaccuum hoses..


you have alot deleted ..po171/174 is a major leak that effected both sides of motor..

the pcv line under the intake is the main cause of leak..

see you may have deleted that? see a plug on back of blower.

i had our motor out a couple times and recall some of these challenges with the codes..

the ford service manual has all of the tests ..PCED manual section

i have the 03/04 on cd-rom,

on cell i go thru here free

Home - MidPointe Library System

Enriching our community through access, experiences and by connecting a curious community.

www.midpointelibrary.org

 

[fordguy_1997]

Thank you guys for the initial responses. I want to verify that the TMAP is the sensor that is sitting in the driver side all the way at the back of the blower, correct? Because that clip did snap so I can’t secure it in place and pretty much rigged zip ties to close the connection. However - I don’t know if it has to do with connectivity or not because it is giving a high input code - not a loss of signal/voltage. Also, when attempting to connect it the code doesn’t change vice when I just unplug it all together. It’s the same error code. I don’t know if that information helps to isolate it further.

One thing I didn’t originally consider - I have the external voltage regulator but haven’t adjusted it. I don’t know what my alternator is outputting, and I’m going to try to run an alternator test with my OBD2 reader to see what that’s outputting. I believe there’s a significant chance she’s not running at 14V and that might need adjusting. I don’t know if that would help to clear any high input problems or if that’s a sensible cause of that code getting thrown in given it’s isolated to that specific sensor.

The lean conditions I’m not too worried about at the moment. I discussed it with my friend group - I sealed the PCV hole at the bottom and the car is potentially seeing far higher pressure than before since it’s no longer operating with a massive vacuum leak. I upgraded to a bigger elbow, JLT RAI and a monoblade. I’m extrapolating that those three things are sending far more air than the stock units therefore the tune isn’t accounting for all the extra air it’s now receiving which is correctable with a proper dyno tune and evaluation of my current fuel system setup. I never had to touch O2 sensors and when I parked the car it didn’t have these issues so I figure everything’s isolated to inside the engine bay.

I’m going to look into all the solutions you guys gave me to start addressing things and will report findings. However, I was told that I may have my vacuum lines messed up and to be honest I wasn’t smart and didn’t label what went where when disassembling which might be jacking things up. If someone just so happens to have an EGR deleted cobra - it would be helpful to get a few pictures with where they have those red vacuum lines running from the blower and where they’re going to.

 

[fordguy_1997]

Adobe Acrobat

acrobat.adobe.com

vaccuum hoses..


you have alot deleted ..po171/174 is a major leak that effected both sides of motor..

the pcv line under the intake is the main cause of leak..

see you may have deleted that? see a plug on back of blower.

i had our motor out a couple times and recall some of these challenges with the codes..

the ford service manual has all of the tests ..PCED manual section

i have the 03/04 on cd-rom,

on cell i go thru here free

Home - MidPointe Library System

Enriching our community through access, experiences and by connecting a curious community.

www.midpointelibrary.org

I’ll look into that link as well. The car had both the PCV system as well as EGR deleted when I bought it. Car was running fine enough (firing on all 8 wasn’t dying and could drive) but they left the hose on the bottom of the intake there so it was a massive vacuum leak essentially. I have since taking everything apart plugged that hole and so it is properly sealed at this point. But I’m also guessing if the car was tuned in that condition - it just might be a cooked tune that’s not liking the fact that the car is actually sealed correctly I suppose? I don’t want to just throw the car to a tuner if there’s problems I need to solve first, but there’s a non zero chance that my tune really isn’t happy with everything I’ve done. I don’t want to have certainty about anything at this point given all the unknowns so I’ll do digging with this and let you guys know what I find.

 

[hotcobra03]

I had cam wire stretched causing po340.

Main engine connection with the 10mm bolt ..c133
I tested wire from there to connection and found issue..

Yes that's the sensor at drivers rear of intake ..

 

[hotcobra03]

Adobe Acrobat

acrobat.adobe.com

U/v wire

 

[hotcobra03]

Intro DU

Adobe Acrobat

acrobat.adobe.com

Pin test DU

Adobe Acrobat

acrobat.adobe.com

Intro DM

Adobe Acrobat

acrobat.adobe.com

Pintest DM

Adobe Acrobat

acrobat.adobe.com

 

[hotcobra03]

Chart for pin test

 

[hotcobra03]

C133

 

[fordguy_1997]

Alright so here’s the conclusion I came to: I’m both stupid and the alternator was making the car mad. I noticed the MAF was backwards and flipped that therefore solving my MAF dilemma. Second - I ran an alternator test via OBDII and was having a voltage of 16V and change. Adjusted the regulator down to 14.2 (I believe the mid point of where it’s supposed to sit) and I haven’t had any codes come in since. Car’s on jacks so it hasn’t been driven as of yet, but I’m thinking keeping it light on the test drive and keeping an eye on parameters should let me know if I’m all good for the dyno or not. The blowers got some metallic scraping sound but it was just rebuilt by Stiegemeier and it was a stage 6 so it had 30-35% overdrives installed. I don’t have reason to believe it’s faulty I’ve just never had a blower so I’m uncertain as to whether or not it’s a normal sound so I’ll wait to talk to them before I go to a dyno to get their input.

I’ll post data once it’s on the ground as has ridden around.

 

[03' White Snake]

Check the voltage with a multimeter right at the battery terminals. It is usually different than at the OBD port.

I set mine with the engine hot to 14.2. When it’s cold, I see 14.4.

 

[fordguy_1997]

Alright guys - did the maiden voyage and don’t have many complaints. Took it out for about a mile or so and did a couple pulls. Didn’t go past 5k RPM as I’m not comfortable with really pushing it until I have it tuned. My blower’s a bit noisy - still getting a bit of rattling/metal on metal sounds almost like straight cut gears, but given it has overdrives in the internals I’m uncertain as to whether or not it’s normal. I’ll try to talk with Stiegemeier and get confirmation of that being alright or not but if anyone’s got experience with a blower and overdrive gears I’d appreciate the input.

Car ran great otherwise. Firing on all 8, no engine codes post drive so I believe my alternator was really just throwing things out of whack. I had my intercooler tank full of distilled water when I began the drive and noticed my tank was completely empty by the time I got back. So I filled it further as I’m assuming it’s just the pump functioning normally and having to fill the heat exchanger. I intend to keep it running on distilled water in both systems since I have radiator flush going through it right now and want it to do its job for a bit before I do the final fill of coolant. I’d rather lose water than actual coolant while I wait for leaks to Identify themselves if they’re present.

I forgot to take the data from the OBDII, so I intend to capture that this weekend and drop it in the forum. I’ll throw together a post detailing the stuff I find in the Terminator talk section since it’ll be less technical Q&A.

I am still waiting for my big 3 kit, and definitely will do an oil change this weekend. I will swap the thermostat for a 170* one as well to help with cooling as the blower and motor did get pretty hot. Hopefully I can get her on a dyno in the next week or so to report numbers and overall health with the car being pushed. After that this journey is over, and it’s on to letting the bank account recover before I begin tackling the suspension as I have some aging parts that are due for a refresh. Diff’s leaky and it seems the 4.10 job was poorly done so that will be something I’ll eventually address as well.

Thank you all for giving me the support over this duration of time of me in essence doing my first real big car project. All the advice and info has been invaluable and I am one step closer to letting my 13 GT get some well deserved rest for a while thanks to all the stuff I’ve picked up while being on the forum.

 

[03' White Snake]

Did you fill and burp the coolant system at the crossover?

With the car off, you should fill the intercooler tank and jump the pump to turn it on. Keep filling the tank. Let it pump until no air is present. Leave a little room at the top of the tank. Close it up and you’re done. It’s a sealed system, should never have to touch it again.

 

[Bullitt1448]

Check the voltage with a multimeter right at the battery terminals. It is usually different than at the OBD port.

I set mine with the engine hot to 14.2. When it’s cold, I see 14.4.

That seems a a little high for battery voltage, I have always used 13.6 - 14.0 unless you're are unning some high draw electrical accessories. You're car, you're choice.If it works for you. no harm no fowl.
.

 

[03' White Snake]

That seems a a little high for battery voltage, I have always used 13.6 - 14.0 unless you're are unning some high draw electrical accessories. You're car, you're choice.If it works for you. no harm no fowl.
.

My 22' F-150, I see over 15 sometimes on my gauge. It is consistently in the 14's. So I figure running big pumps full time and the battery in the trunk of my car, I don't want anything less than 14. This is from my truck..