Ok guys... I just got the 4.9L swaped from the white truck below to the red truck. The problem is blowing gas out the top of the carb and no start.

I have checked for spark and sealed the top of the pistons with a little oil. I also had to swap the distributor over becase the white trucks engine had the newer electric distributor (86 engine)... So I swaped over the older dura-spark distributor so everything would be the same (red truck is an 83)...

I did check the timing. Manualy cranked the timing divit into the timing mark range and checked to make sure #1 piston was on TDC. Then set distributor to hit the #1 piston wire. Turned the engine over tons playing with the distributor position... So I think it's the carb...

The carb is blowing gas out the top and seems like it has a leak bubbling gas out on the bottom some where. I found this post.
Ford F150 - 4.9 Gas blowing out Carb - Ford F150 .net

Seems like these little 1 bbl carbs are a PITA. I do have a dual plane and holley 390 4bbl on the way, I also have a rebuilt 1bbl that i know runs... I wanted to get the engine dialed in with the 1bbl and then put the 4bbl on next summer... Guess I'll quit blabing and wait for advice from you guys.

Keep in mind I am a EFI kid so am not good with carbs... Would the holley be easier to work on?? Thanks for any help guys!!!!

 

Sounds like the one barrel is getting to much gas and causing a flooding condition. You need to correct this before the engine will start. The one barrel is not too hard to work on but just take your time and be patient.

The holley 4 barrel is a nicer setup and will give you more power.

 

you have a pluged exhaust system probly the muffler

 

I know the exhaust isn't plugged... was just replaced less than 6-8 months ago... new muffler... no cat...

I have two conflicting theory's right now... to much gas to carb. Doing rebuild now so we'll see if that solves it...

The second one is one i am hoping is not true... I unbolted the mains to replace the berings with better ones... well I had to pull the crank up a bit to get the gears in... IE seperated the crank and timing gears... when i went to bolt it back down the gear teeth were resting on eachother, so i had to rotate the crank a little to get them to "re-seat/ mesh" back together... So I might have inadvertently rotated the crank the wrong way, thus putting the timing of the valves and piston strokes all out of wack... ugh... i really hate to think about opening the front of that engine all up again!!!!!

 

pull the valve cover and check valve timing.or better yet put your hand over the carb inlet and crank it over and see if you get back pressure.

 

will do... I am hoping for a flooded carb and the float alignment to be off... I am definatly thinking i have back pressure though since the carb blows the gas out the top and all over the underside of the hood and all over the engine...

 

Are you sure the distributor isn't 180* out of time? #1 is at TDC twice. Once at the top of the compression stroke, and again at the top of the exhaust stroke.

 

I think so... I found the timing mark and made sure it was in the middle of the timing slot (the timing slot is the little thing that looks like a small curved saw blade on the top passenger side of the harmonic balancer right?)

anyway i put the timing mark in the middle of the saw blade looking thing and the #1 was at TDC. Then i set the distributor to match so it would fire the #1 piston at TDC. I guess my question is can i still be 180 out of time?

Hmmm... 180* turn of the crank only brings the piston to the bottom of the stroke... right? so I guess 360* trun of the crank brings it back to TDC, and since it's a 4stroke engine... it only fires every other time it's at TDC... I know this is the stupidest question ever but... does the distributor fire every time the #1 piston is at TDC? I guess you would be re-igniting the exhaust fumes as they exit... so I am guessing the answer is no...

I suppose the answer is to try and turn the timing 180*...

 

Cam and dist turn at 1/2 the speed of the crank. 360 turn of the crank = 180 turn of the cam/dist. So, yes, it can be 180 out, since the crank turns 2 times for every 1 turn of the dist.

 

Sounds to me like you have the timing gears out of time.You may want to sort that out before you catch your engine on fire.Ignition timing shouldn't cause that gas to blow out like that,and if it should fire the plug with an intake valve open,you got a fire.Pull the valve cover and no.1 plug,turn the engine with a wrench to Top Dead Center,as you rock the crank back and forth,the piston should stop movement at TDC.If it is late or early,your cam is out of time.When both valves are closed,it would be on compression stroke and you could tell roughly where your ignition timing is,IF the cam timing turns out ok,But I doubt that it is.Be careful!!! many people have been burned by carburetor fires.

 

guess I never looked but is the cam gear keyed? I am thinking i will have to unbolt the front of the oil pan (good thing i put a 1 piece on instead of the 4piece), and disasemble the front of the engine down to the timing gears... Check to make sure the timing gears are aligned first...

If not, I should be able to pull the cam gear off, and then turn the crank until the cam gear is able to be realigend when putting it back on... I would assume that they have alignment dots like my 351w timing sprockets do..?? My 351w crank dot sits just a little to the left of the cam dot; is this the same on a 4.9???? Anyway that should realign my gears and my bottom end will be ok... then just figure out the timing for the distributor...

 

It's a big picture, so you can see the detail. Yes, both the crank and cam are keyed, so they can only go on one way, and both gears have a timing dot that needs to be lined up perfectly.

1981 Ford Bronco Cam Install picture | SuperMotors.net

 

PERFECT! awesome pic... I am sure i will see just that after I open it up for the second time! I don't even want to think about pulling the harmonic balancer while the engine is in the truck... $h%t!!! i hate thinking about that complete disassembly again... The worst thing is that there were 4 of us motor heads standing around when i put it all back together and none of them saw the problem and warned me! Well with it being a balmy 30* out this week and getting colder here in DSM I might have to store the truck untill I can get to it next spring...

 

Hrmm... There's a chance you could slide the cover out of the way without pulling the balancer, but that would only allow you to look. If anything needed to be done, yes, the balancer would need to be pulled.

I think you'd still need to though, since I don't think you could move the cover forward far enough to clear the timing gear teeth.


I just did a full cam install a week ago, so I know how not fun it is to get in that far. There's a lot to do before you can even access the cam.

 

I might just slide the cover to see if that is what the problem is before i do the whole tear down...

as long as i have you here AbandonedBronco... Is there a aftermarket "y-pipe" for the EFI manifolds??? I am planning on pulling a set of EFI manifolds from the junk yard for this motor when we swap to the 4bbl next spring...