help! stumped

[cashmoney37]

my 2000 mountineer with the 5.0 is missing and backfiring. i cant figure out why? i just changed my plugs, wires, coil pack, pvc, cleaned maf, cleaned iac, new fuel filter, sprayed all oround intake and vacum lines with carb spray for leaks. there dose not apear to be. and i have no check engine light.

the truck when its cold seems to run just fine. but as it warms up thats when the missing starts. it starts out missin under a load. then as it gets warmer it start missin when ever, somtimes it smoothes out the hessitates again. it back fires once in a while. after its warmed up the idle in gear is real low and it up in down like it wants to die out. i have no clue what to check from here the truck has 111,000miles.

im going to silver lake sand dunes in two weeks i need to figure this out. please any body have any thoughts on this???

 

[cashmoney37]

nobody ever had an issue like this befor? there has to be some info out there

 

[v8mouse]

make sure your plug wires are all in the right order, maybe you mixed a pair up? Did you gap the new plugs right? Did you use an oxygen sensor safe carb spray?

 

[corkey]

i would get a code reader and check for codes anyways,
a miss when hot can be a couple of things,
an catalytic converter being plugged up ,
or maybe even a hot fuel vapor condition, or an injector,,

 

[cashmoney37]

if the check engine is not on can there still be codes thrown with out a light?

 

[corkey]

yep, the codes can be stored and the light not on, mine does it, if the condition goes away the light will go out and code still be there,

 

[blakshukvw]

Make sure your plug wires aren't touching the exhaust mani. Start by checking fuel pressure. Check for vacuum leaks in the intake system as well.

 

[cashmoney37]

i have the tqm headers and the plug wires are so close to them. the wires are new, but i did check resistance on them and they were good. as for fuel pressure, when i changed my fuel filter, the line from the tank, the fuel was dark nasty, but the line going to the motor was clear clean.

how do you check the fuel pressure? i have never done that yet.
how do you test injectors?

 

[blakshukvw]

i have the tqm headers and the plug wires are so close to them. the wires are new, but i did check resistance on them and they were good. as for fuel pressure, when i changed my fuel filter, the line from the tank, the fuel was dark nasty, but the line going to the motor was clear clean.

how do you check the fuel pressure? i have never done that yet.
how do you test injectors?

You'll need a fuel pressure tester. Most parts stores sell them or Harbor freight as wel. Their is a port on the rail on the passenger side of engine center-line behind the coilpacks. Should have 65-72lbs at all times. Should hold when turned off for a while as well.

 

[cashmoney37]

thank you, im gona go see if i cant rent one. i will get back and let u know