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10-25-2007, 07:39 AM   #1 (permalink)
keithrowe99
 
Join Date: Jun 2007
Posts: 5
89 F-150 5.0/302 Large Quantity of Unburned Fuel in Exhaust System...need some help

In the beginning of the summer, I made the following modifications to my 89 pickup.

- New Upper/Lower Intake
- MAF conversion (new computer, added additional 02 sensor, fuel injector harness, new MAP/BAP sensor)
- new plugs, wires, coil, distributor cap/rotor, igniton control
- 24lb injectors (left factory fuel pump)

Truck ran great for July, Aug, Sept, no issues except one.

Check engine light came on every now and again, upon inspection, I noticed the passenger exhaust header was cracked (this later came off in two pieces). This was approx three weeks ago. I replaced with a new set of Hedman Headers which also had me move the O2 sensor higher up on the header itself. Plugged the old 02 hole in the Y pipe cross piece.

In working on the headers, I noticed a large amout of oil in the upper intake, as it was dripping out of improperly plugged hole in the bottom of the upper intake. I also removed the plugs/wires in this process.

I ran the truck for about a week (in the dripping oil state), and started to notice really bad miss-fires on the highway, didn't appear to happen in normal street running. The miss-fires resulted in a big loss of power. I then pulled off the upper intake, plugged the hole properly. Just to be sure, I pulled off the valve covers both sides, replaced the gasets, it appeared that one of the factory covers was slighly warped, so I replaced with a new set of valve covers (much nicer than the factory). Put everything back together but the miss-fire was still there, so I then replaced all plugs with new plugs (went down a heat range back to factory and factory gap). Took the truck for a test run, and the miss-fire got 100 times worse and then started smoking out of the tailpipe with a large smell of fuel coming out of the engine compartment.

Next after running and smoking at idle, I pulled the plugs, and I noticed that No 3 plug was wet with gas, all others appeared ok. I assumed then the wire was bad, replaced, the wire and the plug and it appeared to go away (the wet plug), however, the engine still idles very rough, and smokes to no end. I'm assuming the smoke is unburned fuel as apposed to coolant due to the horrible gas smell.

So that's where I stand today, I'm not sure where to go next, perhaps, in my travels I dislodged/broke something (injector, coil wire, I don't know). Any help would be greatly appreicated, and thanks for reading through my long winded post.

-Keith
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