i have a fuel issue...maybe....... not fixed!

[G_Body_Enthusiast]

i start the car today...and it has a miss. when i rev it it acts as though it has a miss. at idle the engine runs fine but if i stab the pedal hard i get what sounds like a miss.

im thinking i have a fuel problem. AFAIK all lines are fine, i even fixed the one running from the fuel pump to the carb. its not leaking, i checked it. i didnt check all the way back to the tank but it if was leaking i'd smell it.

it might be that the gas is stale but...this wasnt happening last week. it just seems to be lacking power when i rev it but runs fine at idle. in fact it runs fine at any RPM if i dont stab the pedal.

i plan on changing the fuel filter and see if that helps, ive looked in the tank before and that thing is clean as a whistle inside. i might also run some fuel system cleaner of some sort to help get rid of any build up it might be getting from running the stale gas.

 

[monte olrac]

what type of carb are you running, also you could have a small vaccum leak, i would say check your plugs and wires, i had a small crack in my wire and it did the same also.

 

[G_Body_Enthusiast]

its just a dualjet. everything is stock.

and i did have a vacuum leak, i fixed it and now the air cleaner door and HVAC work again.

though i noticed the engine idled higher than usual.

 

[Blake442]

Has it been wet in your area lately?
I'd check for any moisture under your distributor cap. After that I'd check for a fouled plug.

 

[monte olrac]

If the distributor is wet apply some wd-40, if your car has been sitting for a while try some stabil with some octane booster and a can if b-12 or you can drop the tank and empty it, i would spray down the carb also, the best way would be to take it off, and use about 2 cans. if you decide to go that route take out you idle mixture screws and spray in the holes real good. when is the last time you had the motor rebuilt? the timing can could be a little streched that would give you a stumble when you floor it until your timing catches up. one last thing to, you may have done so already but check the vaccum line going to the distributor it normally would only have vaccum at part throttle

 

[G_Body_Enthusiast]

ok let me give more info so you can help me out a little better.

its an 85 GP, stock 3.8. distributor is fine however...it might be a plug but i wanted to get through this tank of old gas first before changing plugs. i suspect running all this old gas may lead to some fouling of the plugs or may lead to some gunk build up in the carb.

it ran fine the other day and now not so much but the car never had a problem with rain.

the engine has had the timing chain replaced though. it's still under 100K miles with the replacement chain.

i'll pull a plug a or two and see what they look like. the engine ran kind of lean before as it had a small leak from a hose that went bad and when i tried revving it then it would rev but acted like it didnt want to rev very much and acted like it had a miss. now that went away after i replaced the hose but is now back. it just seems like the engine is running lean when i stab the pedal. or the gas is just so stale it needs to be burned up asap but i might siphon the rest out and get some fresh gas soon.

 

[monte olrac]

We'll i could be the gas so i would put some stuff in it just to see how the car reacts and just check those plug boots, there known for cracking, either way you'll be doing on step at a time until you figure it out...carb float maybe and fuel filter...

 

[G_Body_Enthusiast]

the car ran a little better today. i found another cracked vacuum line with the front vacuum break but fixing this changed nothing. it ran ok and gradual pedal pressure lead to the engine revving just fine but again has a problem with it being stabbed. i think i need to fix the idle after it warms up. it seems a tad too fast, like 100 RPM or so.

the fast idle works fine which i had a problem with before.

it has a slight shake at idle which makes me think ignition....

i need to replace the fuel filter and plugs anyway. after this gas is gone and i get a fresh tank i'll start doing the stuff i planned on doing anyway and see what happens after that.

im starting to think this might be an ignition problem. i think i have a wire or plug or both going bad. it wouldnt surprise me if i had plugs fouling because of this stale gas.

i had planned on replacing the cap and rotor, coil plugs and wires and maybe even the module just so i can have a fresh new ignition. i may drop in an ignition box to help out.

i need window sweeps first though...100 bucks for those alone.

 

[monte olrac]

well when you figure it out let me know the outcome

 

[G_Body_Enthusiast]

im nearing 1/4 tank of gas left so i'll be getting new plugs and a fuel filter soon. i might get wires too. so 40 bucks in parts MIGHT address this issue.


i did notice as i slowly revved the engine once it got so far in RPM the more i pressed the pedal the RPMs started to go down some. didnt miss or anything but certainly seemed to lose power.

im hoping its just stale gas and once i get a fresh tank and replace some parts this will go away. we'll find out soon.