so ive been making 100 mile trips for work in my 03 Mustang GT and after about an hr of driving once in a while it will have no power then struggle to keep up speed this will come and go. then it got really bad after about 98 miles of driving it had no power and no throttle responds it just kept loosing RPM and then it shut off. let it sit for a min had my buddy turn the key while i was under it i can hear the fuel pump turn on nice and strong. and then as he started it i had a screwdriver on a fuel injector and could hear it clicking. took a few times but it started. The no power doesnt feel like a miss fire its not bucking or back firing or popping or anything just no pedal.

Ran to autozone had codes for Bank 1 and 2 rich. and Cyl 5 miss fire and Vac leak. i cleaned the MAF and found the vac leak was my PCV hose going into the intake tube had came off.

pulled cables off the batt and drove the 100 miles home ran good for about the first hour then it started the no power thing again and as i got off the free way it had a heavy miss-fire that felt like a plug miss but then it cleared up.

also not sure if this has to do with the issue but when i fill my car up i cannot leave the pump on full it clicks the nozzle off as if the tank is full i have to sit there and play with the handle for a while to get it all in. could that be the filler tube? or is the breather clogged?

i replaced all 8 plugs and coils this weekend as well as the fuel filter. the fuel filter looked like it had never been changed and was quite hard to blow through.

all 8 plugs looked pretty good but plugs 2 3 4 had a red tint on the ground strap? never seen that before.

 

Red can be from additives in the fuel

 

Gotcha well made the trip yesterday ran great for an hr then started hesating then a few miles from my work it started running real rough like it had a giant vacuum leak a few hrs of the car being off it ran great again any ideas?

 

Any ideas?

 

It the vent tube is clogged you won't be able to fuel the tank and it might be causing a fuel starvation issue if the pressure is being thrown off. Next time you have a problem open the fuel cap, listen for a hiss and see if it starts up with the cap off. If that helps try making the drive with the cap loose and see if the problem reoccurs.

 

Shifty, you didn't put off-road diesel in your car, did you?

 

no off road diesel but i filled up with shell gas and left the gas cap off on the way home and didnt have any probs at all the *Check gas cap light* didnt even come on either.

but when i went to get back on the freeway i hammered it and it wouldnt go over 4,000 RPM.

Today i hammered it and it hit 6,000 RPM no probs.

so what do i need to replace the filler neck?

 

Cats are just about plugged, -or someone shoved a potata up your tail-pipe.

 

Midas can check the cats to see if they are plugged. I had them check one ages ago and they drilled a hole in the exhaust pipe ahead of the cat and used a gauge to check the pressure. Then brazed the hole up.

Check the fuel pressure when it is acting up.

It also could be something electronic getting too hot? Maybe?

 

Since the PCM didn't code for the gas cap, I'm inclined to think the PCM is headed south. Might pull the kick panel and give it a smell. If it smells burnt, yer on borrowed time.

 

car ran fine the last 2 trips the gas cap off. going to try replacing the filler neck.

 

Should just try a new cap first...imo

 

New cap might not fix it. it runs better with the cap off. But when i go to fill up at the gas station i can only get .30-.40 cents at a time in and it clicks the pump off.

 

I'd take a good close look at the evap system.