Ok, first things first, I'm a V8 chevy guy, I like power and loud exhaust. Long story short, I've got a 70 gmc, with 383 stroker, and a 82 CJ8 with a 383 stroker. Both motors I built and both with headers. My primary work car broke a year ago so I bought a 84' f150 I6 300 4x4 with carter 1 barrel carb 4 on the floor. Never been a Ford fan. It was cheap a got me to point A to point B. It won my heart over and brought tears to my eyes last winter. I was chugging down a winter road with with a 18' car hauler on the rear with my busted work car on it. We went threw some serious snow drifts and snow banks in 4low in second gear, my sumbichin heart almost stopped. That motor has amazing torque, and starts on a dime at 20 below. I have the most outright respect for that motor.

Now the problem. Last week I wanted to see what it sounded like with headers. Friday nite put the headers on, I know what Im losing with the oem intake and exhaust manifolds, but I wanted to hear what it sounded like. Fired her up, sounded like crap, sounded like a helicopter taking off. So I put the oem exhaust and intake back on. Problem,,, the intake and exhaust manifold are bolted together by three bolts which I broke taking it off. So I drilled, tap, and threaded them and replaced the gasket, also replaced the gasket on the block for the intake and exhaust manifold, and ran a new exhaust system for it so it will be quieter, haha. Fired it up saturday morning with all oem back on, IT SPUTTERS AND BUCKS AND HAS A Loss of power now, I thought it was a vacuum prob..when I pulled the carburator off, but im not that dumb, I know I replaced all the tubes.. Anyways I was checking the distributer and the wires they all have spark.

I pulled the cap off the plug on the first piston closest to the radiator, (i forgot the firing order) and the bucking and sputter don't change, ok, put it back on, pull the cap off of plug 2 the engine dies, 3, 4, 5, 6, are the same way, the engine dies. So this tells me the engine dieing is compensating for the loss of the cylinder whichever plug i pull. But the cap off of plug 1 doesn't kill the motor which tells me that 1 isnt firing which is causeing the bucking and the loss of power.

But I'm having a hard time believing that the number 1 cylinder isn't firing cause when im in fourth gear doing 60mph, it runs just fine. The bucking and choking and sputter come from, when idling, when driving in 2, 3, and reverse. I also thought, when I was drilling and tapping the intake and exhaust manifold, I may have left shavings in it and one of the valves are stuck open because of this. I'm going to crack the head open on friday to see whats opening and closing. But my mind says it maybe a vacuum or an intake leak. Any insite and problems out there like mine will be helpful.

I'm fustrated as heck, I turned a excellent running motor into a pos.

 

Hi Mitch,
Check the obvious first. Make sure you're getting spark & compression at the # 1 cylinder. If that checks out, I'll bet you have an intake leak at the #1 runner. Confirm this by spraying some WD40 all around the intake gasket seal where it enters the head at #1.
I had the same problem when I did a head job & the #5 cylinder wouldn't change the motor when the wire was unplugged. Ran on 5 cylinders till I realized I had deformed the intake gasket on that runner. Make sure you torque the intake/exhaust manifold exactly as the book states. I believe if you seperate them, you must first mate them loosly together, tighten the intake/exhaust to head bolts/nuts, then go back & tighten the 3 bolts holding the intake/exhaust together. I didn't have to do this step because I never seperated the 2 so check to verify.
Let us know how it works out & good Luck!!!

 

Well here's an update.... Thanks, f15084,,, I did exactly what you posted before I read it, haha. I replaced distributor, wires, and plugs. Thank god cuz I would have had to do that before winter, they were in bad shape. After looking at the distributor points, it's hard to relize how it was firing in the first place. I checked compression in cylinder 1 and it was at 120, and in 2nd was,130, 3th,150, 4th 160, 5th 165, 6th 180. So I think it falls pretty good withing range. I put a couple of squirts of oil in 1 and 2 to help keep better compression in them.

I double checked the vaccum tubes and followed diagram and there all at norm.... exept for what I disconnected from the smog box. I sprayed starting fluid around intake gaskets around the block and,,,,,,,what do you know,,,,,,,the engine comes to life... Grabbed a 9/16 wrench and the son of gun bolts where all a half turn loose.

Bam... Intake leak. In conclusion, what I failed to relize was that after 25 years of life of that motor, taking the intake and exhaust manifold off,,,,,, you should suspect some type of warpege. And I failed to inspect them properly if indeed that they were warped. I put them on warped with a new gasket and they have not seeded properly yet, which caused my motor to run bad. So I'll tighten them daily until they find there proper home again. I really dont have the urge to take them off again,,, or the money to buy new ones. Since tightening them today, I've put 32 miles on it and its running better then it has sence last sat.

FYI,,, If you ever take you intake off and find that its warped. If you dont have the money to buy new. You can easily buff and grind the warpege down again with PATIENCE. Good luck all.

 

"Make sure you torque the intake/exhaust manifold exactly as the book states. I believe if you seperate them, you must first mate them loosly together, tighten the intake/exhaust to head bolts/nuts, then go back & tighten the 3 bolts holding the intake/exhaust together".

Would tend to think above quote is your warpage. Loosen the bolts securing intake to exhaust, retorque both manifolds to head and secure bolts.