Strange miss-fire

[william]

Here's the run down i have a 90 festiva with a b6d swap from a 91 capri. The swap has been completed for several months with no problems and getting around 38 mpg mixed driving. I don't drive her two hard but like to have fun with it eveyonce and a while. but about a week ago i noticed a slight erratic miss when accelerating under heavy load but went away if you let off some or dropped a gear. this problem seemed to just go away by its self till the other night.


So the other night me and my girlfriend went to town to eat ( about 30min drive) and after we ate i noticed that my lifters were a little rattly so i shut it off and checked the oil i was about a 1/4 of a quart low so i went to walmart just down the road wile i was on my way there, the miss came back slightly worse than before. I went in to walmart and got a quart of Lucas ( i usually add Lucas when i give it an oil change but didn't on the last change) the reason for adding the Lucas is because when i first put this motor in it would smoke slightly on start up (valve seals??)
So after topping off the oil I headed home with the miss not getting any worse until about 6 miles from home . being dark I could really do much i figured it was spark related so I limped it home were I checked for arcing with the hood up in the dark and didnt see any.

The next day i checked the cap and rotor and wires all seemed ok, the cap did look like it needed to be changed and there was some slight corrosion on one wire on the cap side i cleaned it the best i could . This did not help so i took the truck to town and tried to get A Rotor and Cap they waned 64 something for a cap and rotor so i said no, but i did get some ngk plugs and cam home and ordered the other things i needed from rock-auto should be here in a few days.

I went a head and changed to plugs they all looked good besides cylinder 2 witch had some oil on it. after changing the plugs and adding connection grease it ran quite a bit better so i figured it was just an fouled oil soaked plug but i took it down the road and it was smoking pretty bad on start up ran great to the floor in the high rpms but i still have a miss if i over shift it and floor it.

Anything i should check while i Waite on my other parts to come in??

thanks in advance ,,, william

[william]

Well i just drove it again to try to see when it misses it only misses if you floor it under 2,000 rpms no matter what gear its in if i am in first, and floor it under 2k it sounds like a 2 step then cuts loose and smokes the tires. I don't get it to runs so good after 2 grand.

could it be timing ? vac advance not working?
I'm driving my self nuts
i guess i should just wait till i get my cap rotor , and wires in lol ,and go from there thanks for looking

[shadetree]

Try fuel pump filter or fuel filter ,sounds like low fuel .

[william]

OK i kinda thought that at first but it runs really good at WOT so i was unsure. I did check were i spliced the wires for the pump and all was good but ill check the filter and pump filter should be good just replaced it when i put in the new tank.

if it helps i still have the stock pump

[william]

Well changed that rotor and cap with on change to the miss the fuel filter is also been changed.
Ill be getting my new plug wires in tomorrow but don't think that's the problem ether.

any other suggestions ,

[zoom zoom]

Could be an injector going bad? Do you have a mechanics stethascope to listen to them click? Or use a long screwdriver to feel for it.

Your not getting an o2 sensor code are you? I don't know how your car is wired up.

[shadetree]

What's the position of you vaf . My first turbo car did what seems like the same thing ,I cleaned the sock and replaced fuel filter and leveled the vaf . Problem was solved . On the other hand I've built two bp cars and a b6d car that have the vaf hanging straight down with no problems what so ever ?

[william]

Could be an injector going bad? Do you have a mechanics stethascope to listen to them click? Or use a long screwdriver to feel for it.

Your not getting an o2 sensor code are you? I don't know how your car is wired up.

no no codes at all, and i tried lessening to the injectors with a piece of garden hoses they all sounded the same. but i don't really know what I'mm lissing for

What's the position of you vaf . My first turbo car did what seems like the same thing ,I cleaned the sock and replaced fuel filter and leveled the vaf . Problem was solved . On the other hand I've built two bp cars and a b6d car that have the vaf hanging straight down with no problems what so ever ?

well my vaf isn't exactly level but its not up and down, i am also running a open element filter so ill try cleaning it and see if it gos away .
is there any way to clean/lube the vaf?

ill report back with the results tomorrow
thanks for all your help

[RhodeStiva]

i have a maf on my festiva. where is the vaf?
my car is doing the same thing it is a '92

[BogusSVO]

There are filters in the fuel rail side of the injecters, they will sound fine, just not passing the amount of fuel it should.

You may want to pull the fuel rail and take a look and see if there is any trash in the filter basket.

[william]

i have a maf on my festiva. where is the vaf?
my car is doing the same thing it is a '92

the vaf is on top of the air box i think that's what your calling a maf.
i have a b6d not a b3 but they both use them

There are filters in the fuel rail side of the injecters, they will sound fine, just not passing the amount of fuel it should.

You may want to pull the fuel rail and take a look and see if there is any trash in the filter basket.

thanks ill pull them and take a look.

[william]

FIXED IT!!!!!!!!!
just got my new plug wires in to day and installed them and it runs great now.
kinda crazy since i tried 2 sets of used wires from running cars and got the same results.
thank you guys for all the input.