misfire?? (long)

[krob725]

i was posting to spark plug thread and it made me think of something.
i have a mid to high speed misfire. it starts about 2000 rpm. i can't tell if it is the ignition or the carb.
here's what i have:
1. stock 2 barrel - recent rebuild
2. stock dist housing with Accel adjustable advance and i installed the new advance springs on the mechanical side
3. MSD 6a and blaster coil
4. bosch platinum +4 plugs
5. big plug wires
6. big single exhaust, no cat
7. all emissions removed. the only vac lines are dist,brake booster, PCV, and of course4x4

all vac lines are new - no leaks
intake/carb gaskets new - no leaks
the wag runs good, i can smoke the Dunlops at will. it pulls good all the way to 100+mph. it idles good and smooth. steady vac gauge.
here's what happens:
trans in park or N, give it gas(1/4-1/3), when rpms get above 2000 starts making stumbling sound like you suddenly removed a couple plug wires or squeezed the fuel line.(new pump,hoses,filters)
i don't notice it much when i'm driving but i wonder if this is causing my poor fuel mileage. i get 11 at best.
i think it might be loose sparks inside the stock dist cap. or the POS carb dumping too much fuel at part throttle?

[ November 07, 2003, 10:16 PM: Message edited by: krob725 ]

[carrotman]

Could be many things but the first thing I would check is the advance springs on the distributor. They may be too soft. Retard the distributor a few degrees. If the high speed misfire occurs later, like at 2,500 RPM, change one or both advance springs to heavier springs.

[krob725]

ok
i'll try that.
anyone else?

[Jeep Craze]

just another thought for ya, that is about the throttle position and vacuum signal that the EGR valve opens at! Unhook the vacuum line too it and plug the end then do the same thing again w/ the gas see if it is still there! I had this happen w/ mine...just a thought. Craig

[krob725]

thanks craig, but i don't have an EGR valve. i removed all of that stuff.

[Mondo Bat.]

Poor gas milage may be due to the following.

Make sure you do the following steps thouroghly.

1. Get out of Rig.
2. Look at emblem on quarterpanel.
3. If it says Wagoneer or Grand Wagoneer, go buy a Geo Metro.

4. Flip off FSJ owners who laugh at you for driving a geo.

[krob725]

Originally posted by Mondo Bat.:
Poor gas milage may be due to the following.

Make sure you do the following steps thouroghly.

1. Get out of Rig.
2. Look at emblem on quarterpanel.
3. If it says Wagoneer or Grand Wagoneer, go buy a Geo Metro.

4. Flip off FSJ owners who laugh at you for driving a geo.LMAO
i get 11, i was hoping for 13 or 14?
i though Geo's were speedbumps :D

[andy d]

could be the plugs. i had a bad one outta the box. the multiple electrode jobs are a gimmick imho, get some real 99cent auto lites. :D