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Ron
Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 35858
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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I have a 2002 Ford E450 Econoline 6.8L V10. The engine has

Customer Question

I have a 2002 Ford E450 Econoline 6.8L V10. The engine has some issues. It is sometimes hard to start it. When it starts it vibrates more than normal. If I push on the gas pedal and let go, sometimes it will stall. No engine codes. I looked at the data stream under cylinder misfires, the number stays at zero for a while, but after several minutes the value starts climbing rapidly.What steps can I take to narrow down what is wrong with this engine?
Submitted: 11 months ago.
Category: Ford
Expert:  Ron replied 11 months ago.

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

Expert:  Ron replied 11 months ago.

Since you are not getting any fault codes I would start with running a fuel pressure test as well as a complete engine compression test to see if all cylinders have good compression and that you have proper fuel pressure. Has this been done>

Customer: replied 11 months ago.
No, I have not done that.What kind of numbers am I looking for for fuel pressure and cylinder pressure?
Expert:  Ron replied 11 months ago.

Normal fuel pressure should be right at 32 to 45 PSI and compression should be right at 135 to 150 PSI per cylinder with some variation.

Customer: replied 11 months ago.
Ron, I finally got to this Econoline and doing the compression test right now.Do all the spark plugs need to be pulled to do a compression test?I pulled the five spark plugs on the driver side, and hooked up the gauge to each cylinder. But after cranking for 5 revolutions each cylinder shows 0 psi. On the two cylinders closest to the cab, the gauge was inside the cab and I was looking at it while cranking. The needle jumps up to 120 or 130 and then immediately drops. What does this mean?
Expert:  Ron replied 11 months ago.

Yes when doing a compression test you need all spark plugs removed for an accurate reading on all cylinders. If you reading 0 PSI on one bank then you are most likely looking at a timing chain problem . If in fact that is the case that would explain they way its running as well.

Customer: replied 11 months ago.
I did the compression test on the remaining five cylinders on the passenger side. Same results, 0 psi. I noticed on one or two of the cylinders when I was disconnecting the gauge after the engine revolutions that there was actually vacuum inside that cylinder.What do i do now?
Expert:  Ron replied 11 months ago.

If you reading no compression then in most cases that usually means your timing chain has jumped on that bank. The next steps would be to remove the front cover and inspect the cam timing.

Customer: replied 11 months ago.
I have no compression on all 10 cylinders. Is that also a timing issue?
Expert:  Ron replied 11 months ago.

You have to have some compression on some cylinders if the engine starts and runs. What happen to the cylinders that where reading 120 to 130 PSI?

Customer: replied 11 months ago.
The compression is only there while cranking and immediately disappears when you stop cranking.
Expert:  Ron replied 11 months ago.

If you having this problem on all cylinders then you have a bad compression gauge. Its not holding pressure if it drops off.

Expert:  Ron replied 11 months ago.

Usually means the valve in the gauge hose is stuck open.

Customer: replied 11 months ago.
Okay, the gauge was bad. With the new gauge the readings are as follows. Cylinder 1 130 psi
cylinder 2 160 psi
cylinder 3 30 psi
cylinder 4 30 psi
cylinder 5 130 psi
cylinder 6 170 psi
cylinder 7 170 psi
cylinder 8 170 psi
cylinder 9 170 psi
cylinder 10 170 PSI.
Expert:  Ron replied 11 months ago.

Okay then that makes more since. So the problem I am seeing now is with cylinders 3 and 4. If you seeing low compression on these two cylinder you are likely looking at burned valves. This means the head needs to come off and a valve job performed.

Customer: replied 11 months ago.
Ron, can the head be taken off in the vehicle or does the engine need to come out? This is an ford econoline.
Expert:  Ron replied 11 months ago.

Do to a lack of clearance on the 6.8, you are going to need to remove the engine.

Customer: replied 10 months ago.
No burned valves, didn't need to remove head. The rocker arms fell out, simple fix.
Expert:  Ron replied 10 months ago.

Glad to hear you got it resolved and thank you as well.