Barely Running!

[Vanner1993]

Pulled off IAC and it is clean, but it will not start today.

 

[Duane867]

IAC is idle air control.

Have you checked your hall effect inside the distributor for burns, carbonation or wear yet ?
How about the throttle full closed switch ? Or the Idle speed/throttle actuator ?
Other then the IAC, mas air ( Or map if you have no mass air flow sensor ), and the air flow meter. You got me stumped.
I gave you all the specific areas to check out to seek out the problem. Perplexing.

You did say there was fuel present inside the vacuum line at the fuel regulator though.

 

[Vanner1993]

The was very little to none but I changed the regulator. My plugs are just covered in gas now tho, they are no longer black. The coil fire is white, the old wires showed orange, but have not seen with new wire, but still does not start. Sprayed starting fluid in the intake, not even a hit. Where is the MAP in an 86? All I did for this to happen was drive down a trail with 6 inches of snow and bottom out, got a push from 3 guys and finally pulled out. Let off the gas and barely ran and sounded like a tractor.

 

[Vanner1993]

What is the hall in a distributor? I replaced cap and rotor, started with WOT yesterday with severe misfiring but today it did not.

 

[Duane867]

Ok I guess the TFI is the ignition control module on your year located on the side of the distributor. It could definitely inhibit spark if bad. ( don't know why I said hall effect I dont think your year has one ) .
Take it off and have it tested at autozone or some where.

This has to be something horribly simple if thats all that happened.

 

[84bluebronco2]

I'm suprised we skipped the ever famous TFI in the first place. Have the TFI and coil pack checked. Orange spark past the wires is a weak spark. You want blue to white.

 

[Vanner1993]

Brand new plugs today, cranked...vroom but with a severe misfire AGAIN!!! Pulled plugs, only #1 and #2 are firing and they are super black. 3,4,5,6 are clean and never even fired. What?

 

[Duane867]

I would look towards your distributor if all but 2 plugs are firing.
Could be the TFI, could be the cap or rotor ?

 

[Vanner1993]

Would the tfi only allow 1 and 2 to fire? I am gonna change it, and the cap is brand new along with rotor.

 

[auto117584]

Sorry to get into this so "late". You said you bottomed out and that's when the truck quit running like it should. I'm assuming that the engine bottomed out? Have you put the the front of the truck up on jack stands and crawled under there and thoroughly inspected for any kind of damage? Can you see scuff marks? Dents? Broken wires, hoses, etc? Have you layed under your truck and considered how banging the earth could have messed something up? That's where I would start. Like someone said, it's gonna be something basic, simple, elementary. Start by looking where contact was made with the ground. By the way, was it just frozen ground, or did you hit a boulder? How fast were you going? What kind of terrain was it, that you would bottom out? This is where the mystery started, we need to know all about it.

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[fyre82]

Be sure to check your oil and make sure that the crankcase hasn't filled up with fuel from the leaky regulator. The only one I had go bad filled my crankcase with fuel.

 

[Vanner1993]

I checked all underneath, o2 wire etc is fine. i have skid plates so it was pretty protected, it was frozen snow, able to walk across it but the truck obviously broke through. I changed the distributor today, along with tfi. Started but ran bad still. I unplugged the MAP sensor, ran a bit better but still misfiring, plugged it back in and just about stalled. I think it may be the map sensor. i am gonna get one tomorrow. Would the map sensor cause it to dump fuel?

 

[Duane867]

Yup.

 

[auto117584]

The oil pressure still on H when cold? Did it do like this before the big thump? By the way, how big a thump was it? And the thump is what changed everything, is that right? Tryin to get my head around it.

 

[Vanner1993]

Oil pressure is normal, I wasn't thinking right because I was mad about it running weird. I was driving down a trail, bottomed out in snow. No traction, 3 fiends got me rocking and finally pulled out in 1st gear. May of been pretty high of a rev but the internals are fine and timing is good. Let off the gas when get onto solid road and started running very bad. Now I am here, brand new plugs are in and #1 and #2 are fouled completely black, the rest did not even fire. Well I unplugged the MAP sensor and it ran a bit smoother still real bad tho, plugged it back in and it almost stalled it was so bad. No thump tho, it was just when I pulled out and let my foot off the gas.