HELP! My "new" Cobra is at the dealership; got warranty and fuel map questions.

TheFleshRocket

Founding Member
Jul 10, 2002
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Southern Ill Annoy
Yesterday my '04 Cobra stalled out on me several times and then finally would start but idle at 500rpm and die as soon as I touched the gas pedal. I was about 20 miles from home so I went to the nearest Ford dealership. They had the car towed there and got it looked at today.

The first problem is that they're waiting to hear back from Ford if they can even work on the car, since they are not an SVT dealership. They did the diagnostic work and concluded that it is the fuel pump, which is what I expected. So since they already know what it is, and it's a pretty standard repair, I'm hoping Ford will authorize the work.

The second problem is that the car has a different pulley on it and an aftermarket tune. (According to the previous owner, the tune was done by Ed at Running with the Devil.) Had this problem occurred closer to home, I would have just had the car towed home and switched it back to stock, but I am under the hope that since I don't think there is any way they can blame the fuel pump failing on the pulley or tune, I just had the car towed to the nearest dealership. Do you think there is any way Ford can refuse to replace the fuel pump under warranty because of the mods?

The third problem is that the dealership said that their diagnostic equipment cannot communicate with the ECU, and that means that it has been chipped. This is the part that I am not the least bit clear on. When a car has a custom tune done for it, how is the tune actually inputted into the car? Does the tuner hook up something like a Diablo Predator to the car and just change the settings (fuel, ignition, etc) in the stock ECU, or is there some sort of more permanent change made to the ECU? I have a hard time believing that a custom tune could cause the ECU to not communicate with diagnostic equipment.

Along the same lines, the dealership said that the car should have given a Check Engine light for low fuel pressure. It didn't do that--no warning lights at all went on. Is a custom tune or a chip something that would disable the car's self-diagnostics?

On a side note, I had the car worked on at a different non-Ford dealership earlier in the day to fix a coolant leak (I was driving to a client's office and the temp gauge started getting near the red zone so I pulled into the dealership that I was driving past) and mentioned that. So when I called for an update this morning, the dealer told me that I should have called Roadside Assistance, and that I'd have to pay $55 for the tow. Apparently they assumed that the car wasn't under warranty (I don't know why you would assume that about an '04--a car that's less than three years old) and called their regular tow guy, and not the "free to warranty" tow people. This is my first car that still has a warranty and the first time I've ever had to have warranty work done, so I had no idea who to call. Anyway, if they get my car fixed under warranty, I'll go along with them and pay the tow fee; otherwise I'm going to refuse.

So right now I'm waiting for the dealership to tell me what Ford has to say. Please give me your input so I can be informed about what's going on.
 
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has your car hit the rev limiter lately? It could be your fuel rail pressure sensor. If you can, see if your oil smells like fuel. I am not positive here,but I think if your car has been chipped it cannot communicate withe there equiptment. I did not think if it had a flash tune there would be a problem. If it is your fuel pump they should work on it under warranty. Hope I have helped...
 
I've only owned the car for a week and a half, and in that time it hasn't hit the limiter. I haven't even had it all the way to redline.

I am not clear on why the ECU would be chipped. Isn't the tune uploaded to the ECU via a device like a Diablosport Predator? What would a chip do differently, and why would someone want to do that instead of using a Predator?

The dealership already determined that it was the fuel pump. They probably ran the volume and/or pressure tests on it to come to that conclusion. So right now I'm just waiting for them to tell me SVT says they can replace the pump, and if that will be covered under warranty.
 
There are two way's to get a tune... Flash device (Predator ot SCT Xcalibrator)
or a chip that actually is plugged into the circuit board on the ECU. I know on my Xcal2 flash tuner it states it can't do a tune if you have a chip in...so I am guessing you can't read info from the ECU if an aftermarket chip is in. Sorry about your troubles so early...
 
Thanks for the condolences. I'm just glad the car didn't decide to act up when I was driving it home--I flew 660 miles to buy it and drove back.

So, if the ECU has a chip, can I just pull the chip and have the ECU be restored to stock? Unless I'm missing something here, it seems pretty dumb to use a chip that interferes with the ECU's diagnostic programming when a flash programmer will do the trick without causing any chaos.

I am actually looking into buying a Predator at the moment, but I am price shopping. The idea of paying $300-$400 for something that ought to cost maybe $200 really bugs me. It's not the outright cost, just that I would feel ripped off paying for something that is about as technically advanced as a 5-year-old Palm pilot.
 
Did the previous owner give you a handheld tuner with the car when you bought it? If not, then it's very likely the car has a chip in the ECU versus a flash upgrade. You might want to call Ed at RWTD and confirm whether he burned a chip for the car or emailed the previous owner a new Predator/SCT flash tune.

Ford CAN void your warranty work if the ECU has been modified. They can refuse to fix the fuel problem solely by stating the changes made to the cars stock programming caused the additional duty cycles of the pump resulting in the failure. You see, to support that smaller pulley the ECU has to command more fuel from the stock system. To do this the pumps need to work harder.

You may get lucky... but I'm betting these repairs will come out of your own pocket.

Sorry...

U.M.
 
Correct me if I'm wrong, but I'm pretty sure that the fuel pump is an on/off proposition--IE there's no way that a chip or tune can make the fuel pump work harder. The amount of fuel injected into the engine is based on the injector pulse width and the fuel pressure regulated by the fuel pressure regulator.

No, I did not get a handheld tuner with the car. I don't understand why someone would use a chip if it can interfere with the ECU's diagnostics when a tuner can accomplish the same thing without the negative side-effects. It just seems... well, dumb.
 
TheFleshRocket said:
Correct me if I'm wrong, but I'm pretty sure that the fuel pump is an on/off proposition--IE there's no way that a chip or tune can make the fuel pump work harder. The amount of fuel injected into the engine is based on the injector pulse width and the fuel pressure regulated by the fuel pressure regulator.

No, I did not get a handheld tuner with the car. I don't understand why someone would use a chip if it can interfere with the ECU's diagnostics when a tuner can accomplish the same thing without the negative side-effects. It just seems... well, dumb.
I agree, chips in today's newer ECU's are only required when someone needs to run 2 or more tunes and doesn't want to spend the 5 minutes it takes to re-flash their ECU. They can then use a "Flip-Chip" and toggle back & forth between say a street tune and a nitrous tune.

As for the fuel pumps... yes there are two on our Cobra's and if I'm not mistaken our cars don't use a standard fuel pressure regulator. The amperage sent to the pumps is controlled by the ECU and that's what regulates how much pressure is delivered to the fuel rail. Higher amps = more pressure. There is a FRPS (Fuel Rail Pressure Sensor) that constantly monitors the pressure in the rails and commands more or less based on vacuum. I'm not 100% sure on all this, but i do know that many Cobra owners will add what's known as a BAP (Boost-A-Pump) which overdrives the stock fuel pumps electronically so they deliver more fuel. It does this by simply increasing the amperage supplied to the stock pumps. This is usually a mandatory upgrade when running aftermarket twin screw superchargers like a Whipple or KB.

You may want to pull the passenger kick panel off and unbolt the ECU and check it for a chip located on the J3 port. The dealership may actually do this for you... which will be bad because a chipped ECU is automatic warranty revocation in most instances. Says so right in the owners manual.

U.M.

*EDIT* The stock Cobra fuel pumps are capable of delivering 119 lph each or 238 lph total. With the addition of a KB BAP the same stock fuel pumps can be electronically pushed or overdriven up to 189 lph each for a total of 378 lph. Just a 1-volt increase to the stock pumps can increase the overall fuel delivery by 10%!
 
I'm a bit unclear--at first it sounds like you're saying that the ECU can overdrive the fuel pumps, but then you mention the BAP. So is there any way for the custom tune to crank up the output of the fuel pump(s) or would a BAP be required to accomplish that?

I ask because I'm just about positive that the car doesn't have a BAP on it, and if it doesn't and the tune can't "overclock" the fuel pump, then the mods couldn't be responsible for killing the fuel pump.
 
The service manager just called me. He said Ford says that the entire warranty is voided because of the pulley, the tune and the cold air intake. I disagreed, stating that Ford has to show that the modifications were responsible for the fuel pump failing. He said that Ford does NOT--they can simply say "the car was modified and the warranty is void". I'm going to look up the Magnusson Moss law to see what it says.

I explained to him that the amount of fuel delivered to the engine is controlled by injector pulse width and the fuel pressure regulator. The FPR is mechanical and the tune can only affect injector pulse width, not fuel pump output. The fuel pump is an on/off device--it's either at 100% or 0%. The service manager sounded sympathetic and said he saw my point there. He said that the Ford rep from Memphis will be stopping by the dealership around 12:30. He said he would discuss the issue with the rep and give me a call while the rep is there.
 
TheFleshRocket said:
I'm a bit unclear--at first it sounds like you're saying that the ECU can overdrive the fuel pumps, but then you mention the BAP. So is there any way for the custom tune to crank up the output of the fuel pump(s) or would a BAP be required to accomplish that?

I ask because I'm just about positive that the car doesn't have a BAP on it, and if it doesn't and the tune can't "overclock" the fuel pump, then the mods couldn't be responsible for killing the fuel pump.
Yes I believe the ECU can control the output of the fuel pumps by commanding fuel pressure changes by varrying the amperage to the pumps. I added the BAP info as a way of backing up my statement that the fuel pumps on our cars can vary their output based on the amperage applied. I was just trying to prove that they are not simply an on/off type of pump as you originally suggested.

U.M.
 
TheFleshRocket said:
The service manager just called me. He said Ford says that the entire warranty is voided because of the pulley, the tune and the cold air intake. I disagreed, stating that Ford has to show that the modifications were responsible for the fuel pump failing. He said that Ford does NOT--they can simply say "the car was modified and the warranty is void". I'm going to look up the Magnusson Moss law to see what it says.
I had a feeling this was going to be the outcome.

Unfortunately he's correct especially when it comes to the addition of the pulley & tune. That's an immediate powertrain warranty buster. Go ahead and look up and quote the Magnusson Moss act all you want. You'll have to take Ford to court in order to force them to PROVE your mopdifications did or did not cause the fuel pump problems. Thing is Ford has more lawyers, more money, and more time than you do when it comes to litigation. By the time you get them into court you'll have spent more money getting them there than if you had just paid for the repairs yourself. That's the big problem with the Magnusson Moss act.

TheFleshRocket said:
I explained to him that the amount of fuel delivered to the engine is controlled by injector pulse width and the fuel pressure regulator. The FPR is mechanical and the tune can only affect injector pulse width, not fuel pump output. The fuel pump is an on/off device--it's either at 100% or 0%. The service manager sounded sympathetic and said he saw my point there. He said that the Ford rep from Memphis will be stopping by the dealership around 12:30. He said he would discuss the issue with the rep and give me a call while the rep is there.
I still think your not 100% correct on this assumption. Again, I'm not an expert on the fuel pumps, but I'm pretty sure their pressure output is controlled via fuel tables in the ECU and varrying amperages applied. Send an email to Ed or James at RWTD for a guaranteed explanation of this though.

Sorry...

U.M.

*EDIT* I'm not 100% sure if it's added voltage or if it's added amperage to the pumps which cause them to increase fuel pressure. :shrug: I do know for a fact they are not just on or off.
 
I haven't heard back from Ed yet (last time I emailed him, he got back to me that same evening and it's only been a couple hours since i emailed him today) so I decided to call over to RWTD to see if I could talk to him. The guy who answered the phone said that Ed works out of his house, so I couldn't talk to him there.

I did ask about the warranty issue. The guy said that the custom tune would only control injector pulse width and would not affect fuel pump output at all. He said the only way it would be affected is if the pump was modified with something like a BAP.

Hopefully the reply from Ed will say the same thing, so I will have something in writing.
 
I just called a friend of a friend who works at the local Attorney General's office and he agrees with me--he said go talk to the Ford rep and if that didn't work out, to come file a complaint at his office and they would look into it. So I will mention that to the Ford rep, but only as a last resort if he is uncooperative.
 
Regardless of whether the fuel pumps are controlled by the ECU in any way is a moot point at this juncture. What you need to find out first is if they have in fact voided your warranty in the Ford Oasis system. Do you have any friends who are mechanics or service writers at a Ford dealership by chance? If not send PM me your VIN and I'll try to call in a favor and have them run your number. The Oasis system will state whether they've voided your warranty or not. In the meantime you need to find out whether you have a chip or a reflash as far as your tune is concerned. I feel this is going to be an uphill battle though as far as getting Ford to fix the problem under warranty....

U.M.
 
Well, I have good news. Great news, really. They are going to replace the fuel pump under warranty.

I went by the dealership around 12:45 but the Ford rep wasn't there. I went to get some lunch and came back about 1:30 or so. The rep was there but was unavailable so I waited around until about 1:45 and then told them I had to leave to take my girlfriend back to work (we took her car because I had to pick up a client's computer that was in the Cobra's trunk). I wasn't more than a mile or two down the road when my phone rang and it was the dealership service manager.

He said that he talked things over with the rep, who agreed to warranty the fuel pump. He said that if there were any other repairs, that they would be looked at on a per-repair basis to see if the mods could have caused them. (I think they expected that the motor might have been damaged by running lean. I'm reasonably sure that's not the case--I was driving the car very nicely when it stalled out and there wasn't any pop or bang or anything sounding like something blew up internally.) I told them that sounded fair and thanked him for helping me out.

So, fingers crossed, I will hopefully have the car back and in good shape in a couple days.
 
Regarding the OASIS report, there's a guy on another forum who used to work at the Infocenter and he ran the report for me. As of yesterday, there was nothing on it except for an outstanding recall (the gas pedal getting stuck to the carpet) which needs to be done. I'll ask him to run it again next week some time to see what's changed on it.