Mach ran fine, pulled in the garage, had rough idle, then stalled out?

[firebird1999us]

Haven't been driving my 2003 Mach 1 a lot lately... it's only got 31,000 since new and I try to start it up as time allows and drive it around or at least periodically keep it on a battery tender.

Yesterday I fired it right up, I let it run in the driveway for a little bit, and then took it for a spin around the block. Ran perfectly! When I pulled it back in the garage I revved the engine a bit - maybe up to 5000rpm. Not to redline. About 2 seconds later the rpm dropped to like 500 and the car started sputtering and experienced a rough idle. I tried to give it a little gas to get it back up to normal and the car sputtered some more and stalled out.

I tried to crank it back up and it sputtered and experienced a rough idle again and didn't fully start... although all lights came on and the starter sounded strong. After that I couldn't get it started again at all. Tried again this morning and while the starter turns fine the car won't even turn over... All gauges were showing normal operating range and the car has about half a tank of gas. Only mod is C&L Air intake that I've had on there since like 2010 or 2011.

My theory is the fuel pump but didn't know where to start with troubleshooting given all the symptoms?

[not a gt]

When you turn the key on do you hear the fuel pump whhhirrrr? Seems our fuel pumps don't like sitting up, though you did drive around so not sure if that is the issue.

[firebird1999us]

Originally Posted by not a gt

When you turn the key on do you hear the fuel pump whhhirrrr? Seems our fuel pumps don't like sitting up, though you did drive around so not sure if that is the issue.

Yeah that's what threw me... it literally crapped out after about 4-5 seconds of engine revving. The car drove great and started up fine prior so that eliminates bad gas too

Thank god i decided to crap out in its spot in the garage!

I'll listen for the fuel pump when I get home

[not a gt]

Other than the sputtering and dying, did it make any strange noises? Off topic but check out this story: I had a 79 F100 that I had a put in a 87 Gt 5.0 but with a Weiand intake and Holley carb. Truck ran for 18 years !! with 0 issues, I went to my GF house and cut down a big pine tree, the pieces were 5 foot each and I loaded 18 in the truck and drove home (60 miles), unloaded and right before I parked I thought idle was a little low, tweaked it and I hit the throttle one time and she died!! I went to start back up and heard a clunk and nothing. Looked under the hood and the harmonic balance was cocked and sticking out about 6" from block and I found belt laying in the yard!! Moral of story is keeping your post at the top so others will chime in

[not a gt]

Originally Posted by firebird1999us

Yeah that's what threw me... it literally crapped out after about 4-5 seconds of engine revving. The car drove great and started up fine prior so that eliminates bad gas too

Thank god i decided to crap out in its spot in the garage!

I'll listen for the fuel pump when I get home

Not necessarily, if there was some trash that settled in tank, driving it stirred it up and it may have got sucked up into filter, when was that last changed?

[firebird1999us]

Originally Posted by not a gt

Not necessarily, if there was some trash that settled in tank, driving it stirred it up and it may have got sucked up into filter, when was that last changed?

Fuel filter... well never since the car has such low mileage. Haven't googled it yet but is that an easy change. I guess the 5 seconds of revving could have stirred it up by sucking more gas into the filter since it ran fine prior to that?

[brtnstrns]

Originally Posted by firebird1999us

Fuel filter... well never since the car has such low mileage. Haven't googled it yet but is that an easy change. I guess the 5 seconds of revving could have stirred it up by sucking more gas into the filter since it ran fine prior to that?

Easy as long as you don't have an independent rear suspension.

[not a gt]

Originally Posted by firebird1999us

Fuel filter... well never since the car has such low mileage. Haven't googled it yet but is that an easy change. I guess the 5 seconds of revving could have stirred it up by sucking more gas into the filter since it ran fine prior to that?

Real easy, it is in the back just forward of the fuel tank in the Mach, you just need the tool that unhooks the fuel line from the filter on each side and the bracket has a screw to drop filter out, the tool looks like this (this is a set but you can buy just one for fuel line diameter)



I will shoot a pic under the car

[Mach828]

There is a little fuel pressure fitting on the fuel rails on the passenger front side. You can test the fuel pressure there. If you see no or little fuel pressure, you'll know its a fuel issue. Don't forget to wear your safety glasses

[firebird1999us]

Thanks a lot for all the help/replies guys! I remember coming here right before I was about to buy the Mach in the 2003 to figure out if I could wax the stripe! lol

Originally Posted by Mach828

There is a little fuel pressure fitting on the fuel rails on the passenger front side. You can test the fuel pressure there. If you see no or little fuel pressure, you'll know its a fuel issue. Don't forget to wear your safety glasses

Since I don't have a load of experience working on cars - is there a specific gauge I need to test fuel pressure? Or do I just need to test that pressure is being released by opening it briefly?

[not a gt]

You can just take a small screwdriver and depress schrader valve to check with glasses on. Turn key on, wait a sec, turn key off and see if line is pressurized..this is the filter

[lcaptmorg]

auto parts store may rent the gauge as well

[VA-Mach1]

Cam or crank censor maybe?

[firebird1999us]

Stuck the phone under the gas tank recording, turned the key, and it made a slight noise like something opening... Unfortunately I'm out of town so it's going to have to sit until I get back. I have roadside through my insurance so I might have it towed to the nearest shop to figure it out. I'm sure a $5 sensor somewhere bit the dust

Never had a car towed so I'm somewhat nervous about that if that's what it comes to

[Mach828]

You can hear the pump better from the trunk. Just lift up your floor mat, and take out the spare. Its pretty much right where the spare sits, just under the floor.

[01yellerCobra]

Could also be the FRPS. If you have pressure pull the vacuum line to see if there's fuel in it.

[jv7]

If you have spare key try that one.

[firebird1999us]

Originally Posted by jv7

If you have spare key try that one.

Sadly I think my ex girlfriend from a few years back ended up tossing my spare key😧

[Lonestar77777]

My guess is bad fuel and change the fuel filter! Always keep you tank filled as when not full moisture forms and Gas breaks down. Got to drive the ponies like you stole them or that get problems!


LS

[firebird1999us]

Originally Posted by Lonestar77777

My guess is bad fuel and change the fuel filter! Always keep you tank filled as when not full moisture forms and Gas breaks down. Got to drive the ponies like you stole them or that get problems!


LS

I tried to bleed the line from the stem in the engine compartment. I felt the little door/stem open and nothing came out so clearly the issue is as I suspected: no gas getting to the engine. I'm going to swap out the fuel filter this weekend... is there a device that I can use to pump the gas out of the tank from the fill lid? I don't particularly want to get a mouth full of gas...

[not a gt]

Originally Posted by firebird1999us

I tried to bleed the line from the stem in the engine compartment. I felt the little door/stem open and nothing came out so clearly the issue is as I suspected: no gas getting to the engine. I'm going to swap out the fuel filter this weekend... is there a device that I can use to pump the gas out of the tank from the fill lid? I don't particularly want to get a mouth full of gas...

No, in the tank is a device (its connected to the fill hose) that prevents you from siphoning gas out the car.

[wolverine81]

Originally Posted by firebird1999us

I tried to bleed the line from the stem in the engine compartment. I felt the little door/stem open and nothing came out so clearly the issue is as I suspected: no gas getting to the engine. I'm going to swap out the fuel filter this weekend... is there a device that I can use to pump the gas out of the tank from the fill lid? I don't particularly want to get a mouth full of gas...

Did you resolve your issue? The reason I ask is because my car did exactly what yours did, lol. Mine is a garage queen as well. Thanks!

[firebird1999us]

Originally Posted by wolverine81

Did you resolve your issue? The reason I ask is because my car did exactly what yours did, lol. Mine is a garage queen as well. Thanks!

I tried a lot of different fixes... We got it started for like 2 minutes and now I can't hear the fuel filter kick in at all. Fuel pump is an odds on favorite... Had it towed to Mo's Speed Shop for a fix and to handle a few other problems that have developed.

[wolverine81]

Cool. Thanks for the quick reply. Gonna have to check a few things on mine before I get it towed to the shop. Update the thread if you can when you get things finished. Thanks again!

[not a gt]

Originally Posted by firebird1999us

I tried a lot of different fixes... We got it started for like 2 minutes and now I can't hear the fuel filter kick in at all. Fuel pump is an odds on favorite... Had it towed to Mo's Speed Shop for a fix and to handle a few other problems that have developed.

Good deal, keep us posted, BTW you are 284 miles from me