How to check bad fuel pressure regulator?
Thread Starter
Member
Joined: Aug 2009
Posts: 151
Likes: 0
1994 e320 sedan
How to check bad fuel pressure regulator?
Hi,
Does anyone know absolute way to check a FPR?
I heard that if I can smell fuel from the vacuum hose connected to FPR, means bad. However, I want to know if there is another way to check.
I don't want to do any guess and keep changing wrong parts.
I have changed a fuel filter, OVP, plugs and wires due to cold starting issue.
Thanks.
Does anyone know absolute way to check a FPR?
I heard that if I can smell fuel from the vacuum hose connected to FPR, means bad. However, I want to know if there is another way to check.
I don't want to do any guess and keep changing wrong parts.
I have changed a fuel filter, OVP, plugs and wires due to cold starting issue.
Thanks.
Senior Member
Joined: Apr 2009
Posts: 301
Likes: 0
1994 E420
What you need is a vacuum hand pump with a gauge on it. Once you have your pump, hook it up to the fpr by simply connecting it with a small peice of rubber hose (but make sure its tight and doesnt leak) and see if it holds a vacuum. If it doesnt hold a vacuum then its bad.
Thread Starter
Member
Joined: Aug 2009
Posts: 151
Likes: 0
1994 e320 sedan
Thank you for the reply.
Where can I get the tool? Can I rent it from some auto parts store?
If you have a picture of the tool, please let me know.
Or if it's that easy, should I just ask a mechanic to do it? I am sure it will be either free or $20...
Thanks.
Where can I get the tool? Can I rent it from some auto parts store?
If you have a picture of the tool, please let me know.
Or if it's that easy, should I just ask a mechanic to do it? I am sure it will be either free or $20...
Thanks.
Last edited by gorillajin; Oct 13, 2009 at 11:02 PM.
MBWorld Fanatic!
Joined: Feb 2007
Posts: 1,297
Likes: 1
From: Connecticut, New Haven
95' AMG SeeThreeSix
http://www.harborfreight.com/cpi/cta...emnumber=39522
Very useful troubleshooting tool. So many things on these cars are vacuum actuated, including most of the climate control components, door locks etc.
Also a generic version:
http://www.harborfreight.com/cpi/cta...emnumber=92474
Very useful troubleshooting tool. So many things on these cars are vacuum actuated, including most of the climate control components, door locks etc.
Also a generic version:
http://www.harborfreight.com/cpi/cta...emnumber=92474
Thread Starter
Member
Joined: Aug 2009
Posts: 151
Likes: 0
1994 e320 sedan
I got the tool, and tested the FPR.
It hold compression just fine. I guess FPR is ok.
Now what should I check?
As I said, changed OVP, fuel filter, spark plugs&wires, and FPR is fine.
Can this be ignition coil?
It hold compression just fine. I guess FPR is ok.
Now what should I check?
As I said, changed OVP, fuel filter, spark plugs&wires, and FPR is fine.
Can this be ignition coil?
