Engine locks up after cranking

[TheWeldingFords]

Hi guys,

I've been fixing tons of things and diagnosing why the truck didn't want to drive over 2k rpm in any gear and why it would stall out when it comes to a stop.

After messing with timing it and fixing vacuum leaks now it doesn't want to start up.

It'll attempt to fire off once in the beginning and then dies out within a second and then its like compression builds up so much the dying battery and the starter can't overcome the load, I've tried a jumper pack and it made no difference in getting it to crank better and overcome the pressure.

I also pulled the codes 32, 67, 95

I'm in pretty dire need to get this thing running reliably in less than a month.

It has all new fuel system and pretty much all new ignition system, the only thing that I have done differently from when it ran a few days ago was fixing the vacuum leaks and removing a sheet metal plate the previous owner put between the egr and the intake, when I was timing it I was getting detonation and read into the egr and what it does to help so I removed the plate hoping it would help.

[ArdWrknTrk]

EGR shouldn't have any effect at idle, unless the valve is stuck and leaking.

Where did you set your timing with the SPOUT removed?

Have you considered that your exhaust is plugged?

[85lebaront2]

EGR shouldn't have any effect at idle, unless the valve is stuck and leaking.

Where did you set your timing with the SPOUT removed?

Have you considered that your exhaust is plugged?

My thoughts exactly Jim, we're dealing with a 37 year old system, which if I remember had two cats, front was reducing, rear was oxidizing and had an air feed either in front of or into it. Air pump and associated system issues would be a dead giveaway.

Matt's 86 F150 needed a good exhaust enema for that reason.

[Gary Lewis]

My thoughts exactly Jim, we're dealing with a 37 year old system, which if I remember had two cats, front was reducing, rear was oxidizing and had an air feed either in front of or into it. Air pump and associated system issues would be a dead giveaway.

Matt's 86 F150 needed a good exhaust enema for that reason.

If I remember correctly the Fords of the era used a honeycomb cat where GM used round pellets. The honeycomb was easily plugged, especially if someone cut off the air injection system to it that allowed it to get up to temp.

However, in my experience the engines would start but wouldn't pull a load - which fits with not wanting to run over 2000 RPM. But if the issue is starting then I'm wondering about the EGR valve. If it is open from carbon or whatever it could cause the engine to be very lean and not want to start. Maybe that is why the valve was blocked off? If that was the last thing that was done then maybe it should be put back for a test? Maybe there are two problems?

[ArdWrknTrk]

If I remember correctly the Fords of the era used a honeycomb cat where GM used round pellets. The honeycomb was easily plugged, especially if someone cut off the air injection system to it that allowed it to get up to temp.

However, in my experience the engines would start but wouldn't pull a load - which fits with not wanting to run over 2000 RPM. But if the issue is starting then I'm wondering about the EGR valve. If it is open from carbon or whatever it could cause the engine to be very lean and not want to start. Maybe that is why the valve was blocked off? If that was the last thing that was done then maybe it should be put back for a test? Maybe there are two problems?

Gary, EGR would make it 'rich' (provide less oxygen) but if too much exhaust entered -when exhaust pressure increased- it could be enough to make it so the charge couldn't burn.

Perhaps there are two problems...

[Gary Lewis]

Gary, EGR would make it 'rich' (provide less oxygen) but if too much exhaust entered -when exhaust pressure increased- it could be enough to make it so the charge couldn't burn.

Perhaps there are two problems...

Well, "rich" or "lean" may be confusing in this case. At least it confuses me. But with a plugged cat and an open EGR valve there wouldn't be much air ingested via the carb so very little fuel. And with already-burned gasses coming back in there'd be little oxygen. Bottom Line: It won't run well, if at all.

[ArdWrknTrk]

Well, "rich" or "lean" may be confusing in this case. At least it confuses me. But with a plugged cat and an open EGR valve there wouldn't be much air ingested via the carb so very little fuel. And with already-burned gasses coming back in there'd be little oxygen. Bottom Line: It won't run well, if at all.

If the 'ideal' stoichiometric ratio is 14.7:1

And ~21% of the atmosphere is oxygen, when you dilute the air with incombustible gases you essentially make the mixture richer because there's less oxygen (by volume) to react with the fuel.

Remember, the point of EGR is to stave off lean 'knock' or detonation, and allow more timing advance.

And, of course the first thing to do is undo the last thing you touched...

But the next thing I would do is loosen the headpipes and see how that effects the trucks ability to accelerate.

 

[81-F150-Explorer]

Well, "rich" or "lean" may be confusing in this case. At least it confuses me. But with a plugged cat and an open EGR valve there wouldn't be much air ingested via the carb so very little fuel. And with already-burned gasses coming back in there'd be little oxygen. Bottom Line: It won't run well, if at all.

I had a Catalytic converter plug on my 1981 300/6. Acceleration and pulling power was cut in half.

The pressure was enough to push gasses past the spark plug insulators, and melt and warp the exhaust manifold, and almost destroy the intake manifold as well. The pressure wanted to go somewhere so it choose the least resistance.

Two new cats, a ring and valve job, a new exhaust manifold, and new spark plugs fixed it.

When the catalytic converter plugs it can cause a lot of damage.

If the EGR was a Backpressure transducer type, it would open more with more pressure it got. So a clogged cat, can effect the EGR negatively.

[ArdWrknTrk]

I had a Catalytic converter plug on my 1981 300/6. Acceleration and pulling power was cut in half.

The pressure was enough to push gasses past the spark plug insulators, and melt and warp the exhaust manifold, and almost destroy the intake manifold as well. The pressure wanted to go somewhere so it choose the least resistance.

Two new cats, a ring and valve job, a new exhaust manifold, and new spark plugs fixed it.

When the catalytic converter plugs it can cause a lot of damage.

If the EGR was a Backpressure transducer type, it would open more with more pressure it got. So a clogged cat, can effect the EGR negatively.

As I recall Ron/Reamer had a plugged Cat but didn't believe me.

He rebuilt his engine and still had the same problem...

Then he disconnected his exhaust, and was doing burnouts.

[TheWeldingFords]

As I recall Ron/Reamer had a plugged Cat but didn't believe me.

He rebuilt his engine and still had the same problem...

Then he disconnected his exhaust, and was doing burnouts.

I forgot to mention this but I have not cats because of the previous owner and I put in a new exhaust a few weeks ago (basically headers back into a dynomax turbo muffler that then dumps out the passenger side before the rear tire) I don't think it would be clogged up with less than a mile of driving it and maybe 30 minutes of idling in total.

I have reversed what I have done and it still didn't fix it.