Idles good but dies when in gear...complete engine rebuild

[Florian]

Here are the videos:

Driver side:

http://www.youtube.com/watch?v=9_n4hsGzRGE[/video]

http://www.youtube.com/watch?v=L7u_qTLJgmc[/video]


Passenger side: (notice the fuel coming out on top of the carb)

http://www.youtube.com/watch?v=t0zlEBEIcuw[/video]

[cdeal28078]

Are you running an electric fuel pump? Reason I ask is on the 1st 2 vids it sounds like a real loud fuel pump when you 1st try starting it.
ALl of the valves seem to be working OK so the cam is not broken in half and the timing chain has not broken. It could have slipped a tooth or two though. I notice you said the coil wire was pulled so that explains why the engine doesn't sound right I guess. I sounds like there is little to no compression and pulling the coil wire MIGHT explain that. You need to do a compression check and then you need to bring number 1 piston to top dead center on the compression stroke by watching the valves on number 1. with it at top dead center make sure the timing marks are at or around 6 degrees before top dead center on the harmonic damper in front of the engine. If it is then the timing chain is good.
I remember when I still had a 302 in my 71 running 85 mph would have been unheard of for any length of time. Especially not for a long trip. It might have been able to do it but I doubt it would have liked it.
clint

[Florian]

Yes, it has a electric fuel pump, the PO installed it just before I went to pick it up because the original one didn´t work anymore. The fuel pump starts to run when the ignition key is turned into position 2. When you leave it in position 2 without starting, the pump works the whole time..

The coil to distributor wire was installed when I tried it yesterday and the engine sounded even worse yesterday.


Just to be safe: compression test: (never did a compression test before)

-all plugs pulled
-turn over the engine for 10 seconds or 5 seconds?

Thanks!

Florian

[70_F100]

Spin it over until your gauge climbs three times (six revolutions of the crank).

I agree with Clint, sounds like no compression at all.

[Dragon]

The carb has a real problem. The float is too high or the Accel pump has a problem. Where does the fuel shoot out of. The Accel pump will only do it when the throttle is moved. The float too high or a stuck or bad float needle will cause fuel to shoot up with every squirt of the pump.

[Florian]

The carb has a real problem. The float is too high or the Accel pump has a problem. Where does the fuel shoot out of. The Accel pump will only do it when the throttle is moved. The float too high or a stuck or bad float needle will cause fuel to shoot up with every squirt of the pump.

It could be that the idle screw is adjusted wrong, because after the breakdown on the Autobahn I had, I changed the adjustment to see if it would make a difference. Also we were pouring some fuel and starter spray down there.

The fuel comes out of the two holes up front on each side of the carb. Made a new video where you can see it pretty well:

http://www.youtube.com/watch?v=UVNAqWIz5Eg[/video]

I bought a can of carb cleaner, you think I should put some of that stuff in the carb, maybe there´s something stuck?


Okay, so today I first tried to start it again. Got the coil to distributor wire on again, but it didn´t make a differnece.

Then I went for the compression test. Cleaned the areas around the spark plugs before removing them to prevent any dirt from falling inside the chambers.

Here are pictures of each spark plug. Number 2 is so dirty because it wasn´t fastened enough. No. 6, 7 and 8 are a bit oily right?























Next I removed the distributor cap and laid the distributor side of the coil to distributor wire on the engine block to ground it. Removed the ground of the electric fuel pump to stop fuel flow. (Was this okay? Should I have let the fuel pump on for the compression test?)

Then I finally measured the compression. There is no compression on any cylinder. Did a dry test on all eight cylinders and also a wet test on No. 1 cylinder only. Wet test on No. 1 had also no compression.

Here is a video of dry measuring the compression on cylinder No. 1. If you look closely you´ll see the needle moving up a tiny little bit.

http://www.youtube.com/watch?v=7kUj3WL1fWI[/video]


What does this mean now? An engine that all of a sudden looses all of it´s compression?!


Next I tried to find the TDC on No 1 cylinder. I turned the engine with a socket and racket on the crankshaft pulley until the distributor was at No. 1 cylinder contact position..like this:



I don´t know where the timing mark is on the crankshaft pulley...is it this?





If it is the mark from the picture above, it was at around half past nine o´clock when the distributor finger was at No 1 cylinder contact point...picture:







That´s all for now.

Thanks!

Florian

[Florian]

I remember when I still had a 302 in my 71 running 85 mph would have been unheard of for any length of time. Especially not for a long trip. It might have been able to do it but I doubt it would have liked it.

Sorry, I confused mph with kmh!!! I drove around 85 kmh, which is about 53 mph...not 85 mph! 85 mph would surely not be good for that engine...I´m driving it max 70 mph sometimes, normally between 50 and 60 mph. This ain´t no race car

[70_F100]

Couple of things, maybe.

It looks to me like the rockers are adjusted too tight, based on the amount of stud sticking above the nuts. Of course, I'm not a SBF expert, by any means, so that could be normal.

Second, if you KNOW #1 piston is at TDC, and your timing mark is around the 9 o'clock position (yes, that's the right mark), I would bet that the timing chain/gears have too much wear, maybe even jumped 2-3 teeth. This would also explain the lack of compression and the gas blowing out of the carb.

Put a ratchet and socket on the crankshaft bolt, and turn the crankshaft until the TDC mark aligns with the timing pointer. Then, turn it in the opposite direction until the distributor rotor starts to move. If you turn your crank more than a couple of degrees before the rotor moves, you can rest assured that the timing chain/gears are shot.

[Florian]

Thanks for you reply!

TDC mark aligns with the timing pointer.

Where is the timing pointer? 6 o´clock?

[Florian]

Already found the answer I think. Should be this, indicated in the pictures:





Will take a look when I´m at the shop tomorrow.

Read in a Mustang forum that TDC is normally around 10 to 11 o´clock on a 302. Mine seems to be around 9 o´clock, so that´s most likely where the problem comes from.

[70_F100]

Yep, that's what you're looking for.

Actually, it's not really necessary to worry about the timing marks to check it like I described.

You can pretty much tell how much slack is in it just by moving it back and forth.

[Florian]

Yes sounds logical. Thanks man!

This also explains the problems I initially had when pressing the clutch after longer highway driving and then stalling of the engine. Pressing the clutch made pressure on the thrust bearing and then the timing chain jumped a tooth and got back to normal after cooling off or after some tries and now it just jumped some teeth too much and won´t go back to normal. Does this sound logical now?

[70_F100]

No, not really.

The clutch and the timing chain/gears really have no effect on one another.

Yes, pressing the clutch in does put somewhat of a load on the crankshaft. If the camshaft were pulling the crank, it would be logical. But, since the crankshaft pulls the cam, there's really no correlation other than it puts a slight load on the engine.

However, this could easily explain why it didn't want to idle.

[Florian]

Okay now I understand. But couldn´t the long distance driving at highway-speeds with higher rpms have stretched or heated the timing chain and caused it to make problems when you drive off of the highway and drive lower rpms again?

Anyways, I´m now also pretty sure that the timing chain is worn out and jumped a tooth or more. Will test it tomorrow and next would be the disassembly then..where I am sure I´ll have some questions again

Thanks everybody for you help so far! You don´t know how much I already learned on this forum!

Florian

[Dragon]

Stop back up to the pics. Number 1 is zero compression park the engine and fix it. I watched the valves run you don't have any rings in #1 or a hole in the piston.

Carb movie that carb is hosed the needle either is not stopping the fuel (shot, toast) or the float is way out of adjustment.