engine missfires now

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Jul 16, 2003 | 09:23 AM

greenyonline

Thread Starter

New User

Joined: Jun 2003

Posts: 3

Likes: 0

From: northeast

engine missfires now

Did some mods now have a miss getting progressively worse. 1991EB 302, put on Bassani headers, cat, muffler and TP, new O2 sensor from NAPA. BTW this is a great system and was recommended by several members here. Everything is high quality and fits perfectly

Anyway, also put in Bosch Platinum truck plugs, ACCEL 8.8 wires, NAPA cap & rotor (brass contacts), K&N RF cone filter (haven't hooked up cold air yet). I didn't notice any problem for about a week or so and it only showed up when I towed the boat and hit a long or steep grade, it would miss but not bad. I tow in both dirtect and OD, switching for hillls. Got progressively worse and now you can detect the miss at idle and while just cruising on flat smooth ground. The last time I towed last weekend it was really bad under load. Checked timing, replaced fuel filter, chkd all hoses and fittings. Next step is to put my old wires back on and then pull the plugs to check visually. ANY suggestions, HELP.

Last edited by greenyonline; Jul 16, 2003 at 09:26 AM.

Jul 16, 2003 | 11:26 AM

BillyBob69

Lead Driver

Joined: Jul 2003

Posts: 7,404

Likes: 52

From: Wheatland, Mo

engine missfires now

Double check the routing of your new wires. I had a similar prob that kept gettin worse til I started checking my plug wires and found that one had a small split in the side and was close enough to the engine to short it out. Got worse as the short made the hole bigger.

Jul 16, 2003 | 11:37 AM

Kemicalburns

Hotshot

Joined: Jul 2002

Posts: 14,285

Likes: 12

From: Bend,OR

engine missfires now

I agree with billy, need to check wires, if number 7 & 8 are to close they can arch as well. get some good looms and route everything nice and neat like. what did you gap the plugs at when you bought them. also if the wires touching the headers it might have melted one boot and is causeing the miss.

good luck

Jul 16, 2003 | 02:26 PM

Big Red Bronco

Senior User

Joined: May 2002

Posts: 122

Likes: 0

From: Mountain State

engine missfires now

I had a fine running Bronco, until I put in the K&N filter. For some Broncos the oil sucked off the filter clogs sensors, especially MAF causing them to read wrong. From that the computer starts "correcting" problems that don't exist.
and it is a slow tumble down hill.
Bruce (Big Red Bronco)