Spark Plugs

[tamadrummer88]

So the mustang was having a hard time running the other day. Hard time starting too. When it ran, it ran like it had a cam in it, but worse. My dad removed a spark plug last night and it was covered in fuel. So were gonna change all the plugs with one heat range hotter. Any idea on what could cause it? 120k long block, long tubes and h pipe as the only mods. New fuel pump and the mass air meter was cleaned a little while back too. FWIW, the car has only idled in my garage and moved probably 50 or 60 feet between our garages. Hasn't seen the road in 3 years but was running fine before.

 

[Gearbanger 101]

Old gas will make her run like poop. You shouldn't need anything other than stock heat range plugs in there.

Drain the fuel out of the tank, fill it full of fresh stuff and take it for a good drive.

 

[toyman]

Probably no spark to that cylinder. May explain the lope as well if it isn't firing. Check for fit and damage.

 

[Grabbin' Asphalt]

Leaky injector

 

[84Ttop]

I would look towards general tune up stuff first. As the others have said, I would stay with the standard plug on your car as well!

 

[Mustang5L5]

I wouldn't change the plugs.


Step one is to run the check engine codes and perform a cylinder balance test. A scanner can be had cheaply or you can do it without one

http://www.amazon.com/dp/B000EW0KHW/?tag=stangnet-20

 

[tamadrummer88]

Changed plugs, but the car still idles choppy, or won't even stay on at all. I guess its time to check codes. How do you check it on a fox? whats the voltages for the TPS and all that? MAF was cleaned a month ago and the car has barely run since.

 

[revhead347]

Like the other's said, going to hotter plugs is fixing the symptoms, not the disease. It needs solid diagnosis, not just new plugs.

Kurt

 

[tamadrummer88]

Figured it out. Vacuum leak on the main vacuum line going to the upper intake. I remember changing it out once before. But that was years ago. Guess its time again. haha

 

[tamadrummer88]

Changed the vacuum line, but still a ty idle. Checked the fuel filter to see if it was clogged, nope, flows free. Heard a sucking sound coming from under the intake, so gonna see if maybe more lines are cracked or if theres a crack in the vacuum tree under the intake. Gonna be taking off the upper this evening.

 

[Killa]

spray some carb on where you heard the hissing sound. see if the idle change.

 

[tamadrummer88]

spray some carb on where you heard the hissing sound. see if the idle change.

Yeah we did. The idle went up and down, so its gotta be something vacuum-related under there.

 

[Mustang5L5]

Run the codes. No point guessing randomly. You can use the code reader linked earlier or do a quick search as this is a frequently discussed topic.

 

[madspeed]

Amen, run the complete set of codes. Many codes dont ttigger the check engine light but will tell you whats going on.

 

[madspeed]

Have you done any recent work to it? Washed the engine perhaps?

 

[Killa]

how old the intake gasket ? intake might be leak

 

[tamadrummer88]

Have you done any recent work to it? Washed the engine perhaps?

Nothing has been done recently. The car hasn't seen a road in 5 years. All its been doing is been idling in the garage here and there. It was running fine, and then one day i went to start the car, and the idle was choppy, like it had a vacuum leak.

 

[Killa]

have you check fuel pressure ? is you fuel pump working correctly ?

 

[tamadrummer88]

have you check fuel pressure ? is you fuel pump working correctly ?

Fuel pump is brand new, less than a month old. Car was running perfectly fine before.

SO completely removed upper and lower intake. got new gaskets for everything. Old gaskets were pretty worn, and i noticed some of the vacuum lines were cracked and possibly leaking. change all that out and not have to worry about that stuff for a long while.

Removed the valve covers, cleaned that up and ill paint it while its out. Gonna replace the gaskets too.

 

[Killa]

Fuel pump is brand new, less than a month old. Car was running perfectly fine before.

SO completely removed upper and lower intake. got new gaskets for everything. Old gaskets were pretty worn, and i noticed some of the vacuum lines were cracked and possibly leaking. change all that out and not have to worry about that stuff for a long while.

Removed the valve covers, cleaned that up and ill paint it while its out. Gonna replace the gaskets too.

Good luck, I hope your car running well again soon