My 305 HO is missing and lacks power. One of the first things I checked was the fuel pressure to see if that was the problem as I had a similiar problem on my RS. Here's what I did and the results: First I hooked up the gauge to the shraeder valve and hung the gauge so I could see it inside the car. When I turned the key on, pressure shot up to about 50 psi, but went down within the first minute or two to 0. I did the same thing 3 times w/ all the same results. Then, I cranked it up, pressure stayed steady @ about 40 psi. Shut the car off and pressure went to 0 in a short period of time. My Haynes and Chilton manuals say that the pressure should stay steady. With the pressure at 50 psi I didn't think there was a problem with the pump. Maybe I am wrong. NOt holding the pressure may be a problem that wasnt covered in the manual.
I have replaced the fuel filter, and checked the timing, everything is fine for those items. I have yet to replace the plugs but I don't think that is the problem. What do ya'll think? Help!!! in advance

 

two things that could cause the pressure to drop quickly are your fuel pressure regulator or a leaky injector. good luck

 

or a bad anti drainback valve in the pump. Or a leaky fuel line. If the fuel pressure is right when its running, you should do a volume test. Some fuel pressure gauges have a tube coming off with a little valve. With the engine running, point tube into bucket and push button. See what happens. Lots of times you can find a pump that can maintain pressure in the acceptable range and not deliver the proper volume.

 

thanx for the help. do you know if this would specifically cause the motor to run terribly? I could not find any fuel leaks and I do not smell gas at all.
LJNOWELL, could you explain what a volume test is and how it is carried out? I do not have such a gauge that has a bleeder hose on it, however, I thought that the bleeder valve on that type of gauge was only to relieve the pressure on the hose for my pressure gauge. I did not know it was useful for some other purpose.
Would a bad antidrainback valve cause the engine to miss and lack power?
I am going to look into how to check the FPR for proper functioning. Any other help is GREATLY APPRECIATED!

 

The drainback valve is used to keep the fuel from draining back out of the line through the pump when it is not running. Not the problem with lack of power. The volume test is pretty simple really. If you hook up the gauge, push the button with the hose directed to a bucket, fuel will start coming out of the hose. In simplest terms you are bleeding off fuel to see if the pump can keep up with the volume demand. If the car stumbles and runs poorly, or loses the ability to accelerate, then you have a volume delivery issue, possibly.