[antnvlz1294]

Hey everyone,
I just bought my first mustang 5.0. Its a 1988 mustang 5.0 lx and when i bought it, it had about 5 gallons of fuel which was regular gasoline (87 octane). I was reading on other forums to not use regular and to use 92,93 octane. I used 93 octane(premium) even though the previous owner stated he used regular in her. Now with about 5 or maybe less gallons i went to the gas station and filled her with the 93 octane premium gasoline. Ive been driving the entire day and now im feeling a little loss of acceleration or power and i hear what sounds to be the engine misfiring and i can hear it because the car makes a popping sound(the sound of misfiring) and i can hear it come from under toward the back of the car thus the sound is coming from the exhaust. Is it because i put in the 93 octane premium gas? My 5.0 engine is stock with the exception of a bbk cold air intake and bbk headers leading to the aftermarket exhaust. Ive had the car since sunday morning and it wasnt doing this all day until about an hour ago. Please help.skep1.gif

Thank you,
Antonio

 

[heavy metal]

Welcome to the site!! I would say the different octane fuel has nothing to do with a miss.I suggest to check plugs,wires,cap and button and fuel filter.

 

[antnvlz1294]

Welcome to the site!! I would say the different octane fuel has nothing to do with a miss.I suggest to check plugs,wires,cap and button and fuel filter.

Even though this wasnt occuring all day until very recently? Should i check the sparkplugs? Whats the button? How do i check.the plugs and wires btw? Sorry this is my first mustang new to the 5.0.

 

[heavy metal]

The distributor cap and rotor button=look for white chalky buildup on those parts.Look at the plug wires for bad spots=cuts,burns,cracks.....Pull plugs and look for buildup,blackness,etc. and check gap.

 

[antnvlz1294]

The distributor cap and rotor button=look for white chalky buildup on those parts.Look at the plug wires for bad spots=cuts,burns,cracks.....Pull plugs and look for buildup,blackness,etc. and check gap.

And im guessing that if it has any of that on it that it most likely needs replacing. Also im unaware of when the previous owner had the oil filter and oil changed would that be a possibility?

 

[heavy metal]

Yes,if you see any of that=replace. An oil change is just a good idea,but not causing your problem.A fuel filter change may help.

 

[antnvlz1294]

Yes,if you see any of that=replace. An oil change is just a good idea,but not causing your problem.A fuel filter change may help.

Okay ill definitely look into that. Would just an overall tuneup probably solve it or at least help? Sparkplugs, wires, distributer cap, oil change and fuel filter? The engines really strong abd its got 99,241 original miles so i doubt its anything serious its probably just something small?

 

[kenv]

Okay ill definitely look into that. Would just an overall tuneup probably solve it or at least help? Sparkplugs, wires, distributer cap, oil change and fuel filter? The engines really strong abd its got 99,241 original miles so i doubt its anything serious its probably just something small?

If you just got the car, i would definitely change all of that + a coolant change.

 

[antnvlz1294]

If you just got the car, i would definitely change all of that + a coolant change.

Without the coolant change what should i replace for tune up purposes? And how much would this run me up $100-130? These things are fairly easy to change too correct?

 

[302 Beast]

Would a misfire throw the check engine light?

 

[antnvlz1294]

Would a misfire throw the check engine light?

Theres no check engine light present. Althougbi do recall the previous owner stating that the oil pan leaked a little what should my oil pressure be around? Stock engine with a bbk cold air intake.

 

[black02GT]

Mine did the same thing. In my case it was the plugs

 

[antnvlz1294]

Mine did the same thing. In my case it was the plugs

By "plugs" do you mean the Sparkplugs, or the Igniter cables(from distributor to sparkplugs)?