Marauder issue

[FCP71]

Hi there everyone I acquired an 03 MM for very cheap couldn’t pass on it, I’m having this issue were I crank the car and I accelarete the car wants to die
Or bugs down, I notice after the car idles for about 10 minutes is much better but still when I hit the gas it wants to die until the rpm go above 2k it’s runs normal it only happens when i hit the gas. I have replaced fuel filter,spark plug,ignition coils, iac.Also there’s a fuel smell coming from the exhaust. This car was sitting for about 7months before I bought it according to the previous owner if anyone can give me some clues or something thank you in advance.almost forgot the car takes for ever to crank takes about 7 to 10 seconds before it starts. No codes

[Jtrip]

No mechanic here but have heard to press accelerator all the way to floor when turning over, shouldn't start. Lift off and try to start. Helped mine once when it had been sitting. Maybe someone else can chime in.

[FCP71]

No mechanic here but have heard to press accelerator all the way to floor when turning over, shouldn't start. Lift off and try to start. Helped mine once when it had been sitting. Maybe someone else can chime in.

It will turn on without having to floor it, I was giving a recommendation to clean the maf so that will be my next step. Checking the catalytic converters will be my second step just to make sure.

[RubberCtyRauder]

todays' gas sitting for 7 months is generally crap unless stabilizer was added, are you using fresh gas? clean throttle body too with throttle body cleaner for coated throttle bodies along with MAF with MAF cleaner

[FCP71]

todays' gas sitting for 7 months is generally crap unless stabilizer was added, are you using fresh gas? clean throttle body too with throttle body cleaner for coated throttle bodies along with MAF with MAF cleaner

I did add fuel treatment with almost empty tank then I added 93 fresh fuel.I have not touched the maf yet will clean it today.throttle body was cleaned it had a lot of build up.

[Mr. Man]

Make sure all your COP's are seated. If they are I'd pull plugs to see if any are wet. You shouldn't smell gas at the rear of the car, assuming you don't have a fuel leak.

[fastblackmerc]

No mechanic here but have heard to press accelerator all the way to floor when turning over, shouldn't start. Lift off and try to start. Helped mine once when it had been sitting. Maybe someone else can chime in.

If you keep the pedal to the floor when starting it shuts off the injectors.

[fastblackmerc]

It will turn on without having to floor it, I was giving a recommendation to clean the maf so that will be my next step. Checking the catalytic converters will be my second step just to make sure.

With it at idle hold your hand in front of the exhaust tips, you should feel about the same amount of pressure at each tip.

[fastblackmerc]

Could be clogged injectors.

[FCP71]

Update cleaned the maf car seems to be running better took it for a drive and it pulls hard but sometimes is sluggish and I hear a ticking noise on the driver side when I step on the accelerator.

[FCP71]

you should feel about the same amount of pressure at each tip.

Tested that pressure seems pretty strong.

[fastblackmerc]

Tested that pressure seems pretty strong.

Then it's probably not the cats.

[crownvic97]

Update cleaned the maf car seems to be running better took it for a drive and it pulls hard but sometimes is sluggish and I hear a ticking noise on the driver side when I step on the accelerator.

Any check engine light? Ticking sound on driver’s side could be the cylinder 7/8 valve issue.

[FCP71]

Any check engine light? Ticking sound on driver’s side could be the cylinder 7/8 valve issue.

No codes at all.

[justbob]

What brand coils did you use? And did you torque the plugs?


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[FCP71]

What brand coils did you use? And did you torque the plugs?


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Oem motorcraft coils and spark plugs

[RubberCtyRauder]

what gap did you use?

[FCP71]

what gap did you use?

gapped at .54

[FCP71]

I will be making a video of the symptom soon.

[FCP71]

Here is the video https://youtu.be/UoCdd18Cizo

The mileage is wrong in this car i found out later through car fax will fix it later.

[justbob]

Do you have a way to data log the fuel? Sounds like it’s dumping fuel thru multiple stuck injectors and they are bleeding off all the pressure (and fuel into the cylinders). Or perhaps the FRPS is failing. Or the check valve in the tank is failing. It did this before you worked on it correct?

If it’s been dumping fuel for long enough the cats will indeed glaze over and “plug” up, but this takes quite awhile to happen. You say it gets better when warmed up, my thinking is the fuel has evaporated and plugs burned dry. Also keeping it over 2,000 is injecting more airflow to the mix and would indeed run better.

I would be curious to see the fuel pressure in a data log and the pressure in the rail prior to start up with a mechanical gauge. Simply pressing in the schrader valve will not tell you anything.

Without diagnosing it could be many things. Cam sensor, wiring, bad or REALLY dirty MAF, ETC.

I’m just going on the basics. Gas smell in exhaust, bad stumbling, seems to clear up after warm or higher RPM.


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[FCP71]

Do you have a way to data log the fuel? Sounds like it’s dumping fuel thru multiple stuck injectors and they are bleeding off all the pressure (and fuel into the cylinders). Or perhaps the FRPS is failing. Or the check valve in the tank is failing. It did this before you worked on it correct?

If it’s been dumping fuel for long enough the cats will indeed glaze over and “plug” up, but this takes quite awhile to happen. You say it gets better when warmed up, my thinking is the fuel has evaporated and plugs burned dry. Also keeping it over 2,000 is injecting more airflow to the mix and would indeed run better.

I would be curious to see the fuel pressure in a data log and the pressure in the rail prior to start up with a mechanical gauge. Simply pressing in the schrader valve will not tell you anything.

Without diagnosing it could be many things. Cam sensor, wiring, bad or REALLY dirty MAF, ETC.

I’m just going on the basics. Gas smell in exhaust, bad stumbling, seems to clear up after warm or higher RPM.


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I can use a fuel pressure tester to check the psi,I had a code regarding the FPRs I bought one and replaced it then the code went away.Yes is still happening after replacing a few things like Coils, spark plugs,fuel filter and FPRS. This weekend I will take it to a reputable local mechanic shop I want to get to the bottom of this. I also notice the air coming from the tail pipe is not as strong.

Here is the video when I first got the car - https://www.youtube.com/watch?v=Of1xOZtBT0o

[FCP71]

Ok guys I seem to fixed the problem, when i first got the car I had removed a blue chip that was attached to the pcm, then I reattached the chip to see what happens and bamm the damn thing starts working perfectly fine and it pulls hard.thank you guys for the help now is time to get back on the road will get a real tune in the future from Marty.

Picture attached of what the chip looks like.
- https://gyazo.com/e492d22f122a2198645012db3f5545 58

[RubberCtyRauder]

chips with tunes was the way to do it, now,evolved to programs direct to pcm saving original tune on device. Glad it worked out, Marty will set you up right

[Turbov6Bryan]

Glad you got it fixed up. Crazy how that chip did that to the car.

[Gerry24]

That was a a lot of troubleshooting. Glad you can put that MM back on the road :beer:

[FCP71]

Thanks guys I wasn’t willing to give up to easy on this one.