1983 Ford f150 300 inline 6 with a c6 transmission.

I recently drove my truck to work and on the work back home it started acting up. Initially started by backfiring out of the carb a few times then it started running good enough to drive. I made it home but noticed it seemed like it was losing power as I was driving. The next day I took it down the road and back. I had to turn around early bc it started bogging down. By the time I made it to my driveway it just lost all power and died.

I figured it was a carb related issue so I pulled the carb and cleaned it, and checked spark. It started cranking but backfiring again. I decided to let a mechanic take a look 8 weeks later nothing had been done so I got it back.

after I got the truck back went all the way down to the timing gears to make sure it hadn’t jumped time or broke some teeth. The timing looked to be perfect tho.

I took the time and ran the crank with the distributor off to verify all the all the correct pistons were coming up and that the distributor was on the correct firing order. All this seemed to be in time.

I just installed a new carburetor yesterday. Today I went to crank it after pouring some gas down the carb and it took to then died. I tried crank it some more and now it’s at the point where it’s backfiring while cranking again. Can anyone point me in the right direction at this point I’m at a loss for words but I don’t know a mechanic that seems to have the time to work on it.

TIA

 

It looks like someone has been at the timing gears as they are both metal from the looks.
The cam gear should be a composite.

Do you still have the cover off or back on?
If off line up the dots again and recheck that the valves for #1 are both closed.
You can either pull the valve cover or the side cover. Side might be easier as you can see where the lifters sit on the holes to see what ones are open & closed.

You said you got a new dist. I was going to say check the gear & roll pin on the old dist.
You might want to do the same on the new one as maybe the roll pin broke on it too?
Before you put the dist. in after checking the roll pin is to check if the oil pump turns.
You need to find a tool that fits into the pump or can drive the oil pump shaft.
Use tape to keep the tool parts together so they dont fall down into the motor.
Hook the tool to a drill and spin the pump. It will be a little hard to turn as the oil will resist some but should spin smoothly.
If it gets jammed that is what broke the roll pin(s) and the oil pump will need to be pulled and check why it jammed.

If you find the roll pins are good and the valves working as they should lets do a compression test.
Even a leak down test might be needed but not everyone has the tools (air compressor) to do this and the compression test can tell us a lot. as a start.
So may say the motor has to be up to temp and the throttle wide open I say BS at this stage as it dose not run.
We just need to make sure all cly have compression and are close to each other in PSI.

BTW you can run the motor without the front cover just to make sure it will start / run and if it dose then put it together.
Let us know what you find with the above checks.
Dave ----

ps with the new dist. did it come with a new cap & rotor or you reused the old?

 

Did he say he got a new distributor? I looked and didn't see that. I would grab the distributor rotor, whether it's old or reman, and try to shake it back and forth and see how much play is in the dist shaft. Also look at the terminals under the distributor cap. Are they worn and corroded in the center or are they all worn to the side of the terminal.

 

I didn’t put a new distributor on it. After reading your comments I’m gonna go back and check spark. I remember checking it but it may have been before I had this issue I’ve been working on the truck for so long its getting hard to keep up with what I have and haven’t done. I’m pretty sure the compressions good I’ll test it as well tho. I was looking up the roll pin being bad today it was saying the distributor will not spin? Mine will spin as I turn the crankshaft.

thanks for the input, good lord what a ford lol

 

I’ll look at the terminals again but when I had the cap off watching it rotate last weekend it they looked fairly good id say almost new honestly.

thanks

 

[QUOTE=FuzzFace2;21262691]It looks like someone has been at the timing gears as they are both metal from the looks.
The cam gear should be a composite.

Do you still have the cover off or back on?
If off line up the dots again and recheck that the valves for #1 are both closed.
You can either pull the valve cover or the side cover. Side might be easier as you can see where the lifters sit on the holes to see what ones are open & closed.



The timing can gear is still composite. I didn’t replace it bc I didn’t feel like it was that big of a job to get to and I didn’t wanna spend the money lol

i did put it all back together unfortunately. I was running the crankshaft with my socket to get the dots on the gears lined up that put the number one piston at TDC. That did in fact put the 1 piston on top. Now as far as the valve go I have no idea I’ll have to look again.

you said at TDC both the intake and exhaust valve should be closed?

I guess that makes sense. Thanks

 

[QUOTE=Quitcrying;21263954]When it back fires is it out the carb or tail pipe?

As for the roll pin and the dist. spinning. Not all of them stop spinning all the way. It can break throwing the timing off (the back fire?) but still spin if the pin drags on the gear. Pop the cap grab the rotor and try and spin it in both directions and see if it will spin.
Dont worry about it moving a little in 1 direction and return back to where it was as this is normal.
I thought you said you installed a new dist. and why I posted what I did sorry.
Even more reason to do the above if it will spin by hand.

Cap still off mark the dist. where #1 plug wire is.
Now turn the crank so it is at TDC. Check to see if the rotor is pointing to the mark.
Remember the timing mark will come up 2 times. If the rotor is pointing 180* then that is not TDC but is a good sign as the dist. is still in time (so far?).

The 2 things that can cause the motor to back fire is spark happening at the wrong time and why checking the crank / cam gears (good) and the dist..
The other is a valve not closing all the way and when the spark happens on the power stroke that power is going past a valve and back fire.
A compression or leak down test can show if this is why the back fire.
Thing is finding where the backfire is coming from then we can plan on a fix.
Dave ----

 

Okay long week but I am back I took the valve cover off and the distributor cap so I could check the valves. It looked like to me it was a 180 degrees out on the timing. So I spun it back 180 degrees. I recorded a video I’ll try to upload it here. I still haven’t gotten it to do anything but it does have spark 100% on that.

Distributor orientation before turning in 180 degrees

Intake and exhaust

here’s the video of me spinning the crank

 

When it was back firing before your 180 fix was it out the carb or the tail pipe?
If you put a little gas or starting fluid down the carb now what happens?

You might still be off on the timing for it to fire off.
You can try and advance the timing, grab the vacuum advance unit and pull on it like you would if you pulled on the hose.
If the motor kicks back, cranks then stops and then cranks again, the timing is too far advance and turn it back just a vary little.
Dave ----

 

since I turned the distributor a 180 degrees I haven’t had it back fire. I honestly couldn’t tell you where it was back firing from bc I’m the only one working on it. I just bought a clicker for troubleshooting it tho. Before I left for work I sprayed starting fluid down the carb and it would crank until that burnt up it. I crunk it 3 or 4 times using starting fluid before I left. When it would crank it would idle very rough and die. The last one was the longest it ran but when I went around to see if I was getting fuel to the inline filter it was completely empty. The inline filter was full before I started cranking is so idk why it’s not accumulating in there right now. I did replace the distributor after it looked like it jumped time. I’m probably gonna pull the gas inlet going to the carb off and see how much fuel I’m getting while cranking. Anything else I should look at? Just lmk
thanks for responding

 

LOL it sounds like your "cranking" with starting fluid is different than our "cranking" LOL

Cranking or turning over is when you turn the key and the motor / fan spins.
This will stop as soon as you let go of the key and the motor either stop spinning or runs.
In your case it sounds like it will run when you spray the starting fluid down the carb till it uses it all up (runs out of fuel) and stalls.

This is good as it is showing signs of wanting to run and we just need to "fine tune" to keep it running.
Lets look at the fuel first.
The in line filter may not show fuel all the time. You can do like you said and pull the line off at the carb and crank / turn the motor over and see if anything comes out. Maybe even a little spray down the carb before cranking.
Just have something handy in case of fire and I dont mean things to make S'mores LOL

Also how much fuel is in the tank and how old is it?
If the fuel is old (over a year) do not go adding good fuel on top of it as the old fuel should be drained,the tank checked for rust or just replaced with the sender and all rubber hose replaced. Even if the fuel is not that old all rubber hose replaced as it can be dry rotted and suck in air but not leak or break down inside and block fuel flow.

I also think the timing needs to be advances some more and why it is running ruff.
Turn the dist. like if pulling on the vacuum hose should advance it.
Good luck
Dave ----

 

I took the line going into the carb off that looked pretty good though. it might not be putting out enough? I’m assuming if the fuel is there it is enough. Here is a video of that.


the gas the fuel pump pushed up


I tried adjusting the timing by advancing and retarding the distributor but I still couldn’t get it to crank. I think most of what it was doing was the starting fluid. Here is a video of that.

 

Ok from what I have seen the volume "I" dont think is enough.
It should have 3x that amount for for the 3 or 4 pumps I saw push out.
What was wrong with the old pump? I know you showed the 2 pumps side by side but I cant say the smaller new pump would be the cause?

Get some 5/16 fuel line and replace the hose from tank to the hard line.
If you have dual tanks do them both. Also if dual replace the 3 hoses at the switching valve on the frame.
Last replace the hose from the hard line to the fuel pump.
It could be the hoses a dry rotted and sucking in air but not leaking fuel. Yep had that happen on a car hose from tank to hard line.

FYI I replaced a fuel pump because I thought it was bad and it was not.I was trying to use 3/8 and even with 2 clamps it would not pull fuel from a can on the inner fender.

Also it looks like the choke is not closing. Being the motor is cold the choke should be only open maybe 1/8"
This could also be why it is hard to start or not stay running. But the fuel above it the biggest that I see right now.

The timing I see you really go to town on the hold down.
You dont have to go that tight and if trying to "dial in" the timing you dont want it that tight.
Loosen it so it takes a little bit of power to move it. but not need to use tools to loosen the hold down.
As long as it dose not turn on it's own you can leave it that way. Mine has been that way for years now.

But what I see if you can get fuel into the carb so it had some to run off of, the choke closed (maybe idle turned up?) she should start and run as it is so close right now.
If you can fill the carb float bowl, hook the fuel line back up she may run long enough to pull more fuel from the tank if the hoses are good.
To fill the bowl you see that little tube sticking out in the carb opening? That is the float bowl vent and if the float was not to close off fuel when full the gas would come out it and go down into the carb & motor flooding it and motor stop so no more flooding and you would then look into why it stopped.
Find something you can put in the tube and fill the bowl. This way when it starts it has more to run off of that what you spray into the carb.
Dave ----

 

last year around August I changed the fuel pump for giggles it did run fine after that. I’m not sure what other pump you seen lol

THIS⬆️ I just replaced that hose coming off the tank with a 3/8 bc I ran out of 5/16 I’ll try to change it tomorrow and buy it before I go into work. Fingers crossed lol

I’ll have to do some digging on adjusting that carb i appreciate the feedback. Ill also try to funnel some down that vent tube tomorrow before I try it

 

My bad I am working 2 different "no run" issues on the 300 six and got them mixed up

Yea change that 3/8 hose for a 5/16 and do the rest like you said and I bet the fuel volume will be better and motor will run.
Dave ----