fuel filter 1987 L98
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Joined: Jul 2007
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From: Tallahassee Fl
fuel filter 1987 L98
My engine stumbles around 2k rpm. Doing some diagnostics, I changed the filter. I've heard that when they are a problem you cannot blow through them.
After the old one dried out I could blow through it with no problem. Does that mean the filter is still good? Not that I'm going to use it, I just wondered.
My fuel pressure gauge reads around 35lbs. The system hold pressure OK. Manaul (Helms) says that isn't enough. Engine has high miles, like I said above, it is stumbling around 2000 rpm. Checked the TPS, it's OK. I just bought a vacuum tester. I would like to eliminate any vacuum problem before I replace the fuel pump. Tips appreciated. I have the Helms manual.
Thanks
After the old one dried out I could blow through it with no problem. Does that mean the filter is still good? Not that I'm going to use it, I just wondered.
My fuel pressure gauge reads around 35lbs. The system hold pressure OK. Manaul (Helms) says that isn't enough. Engine has high miles, like I said above, it is stumbling around 2000 rpm. Checked the TPS, it's OK. I just bought a vacuum tester. I would like to eliminate any vacuum problem before I replace the fuel pump. Tips appreciated. I have the Helms manual.
Thanks
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Joined: Jul 2007
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From: Tallahassee Fl
engine stumbling
yes it holds pressure and I just finished a flow test at the pump and it flows about a 1/2 pint or more of fuel in 15 seconds, what the manual says it should - of course that doesn't say much about the pressure, but it is flowing. The FPR is old enough to have a problem.
Thanks, all tips appreciated.
Thanks, all tips appreciated.
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From: Tallahassee Fl
I have not eliminated the EGR as a problem but I intend to test it next.
Yes the plug wires are old enough, I will replace.
Does anyone know the answer to my question about the fuel filter? When it is dry I can blow through it with no problem, given that, I don't see it causing a problem at approx 35 psi fuel pressure. ???
Thanks
I've owned this car for 22 years.
Yes the plug wires are old enough, I will replace.
Does anyone know the answer to my question about the fuel filter? When it is dry I can blow through it with no problem, given that, I don't see it causing a problem at approx 35 psi fuel pressure. ???
Thanks
I've owned this car for 22 years.
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From: One day you're a Comet...the next day you're dust... Arkansas
Actually I have never blown through a used fuel filter, however, it sounds like that wasn't the problem. Isn't your fuel pressure supposed to be around 42 - 44 psi? I think your pump might be OK. It would be worth replacing your FPR. I would just get an AFPR.
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I will sneak a peak in mine when I get home.
If your fuel pressure remains in spec, and holds steady at max load (wide open throttle climbing a hill for example), fuel pump is likely fine. As far as the filter, forget about blowing through it. It is restricted to the point of starving the motor for fuel, or it isn't. Duct taping a fuel pressure guage to the window and observing it while driving is a good way to collect info.
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From: Tallahassee Fl
Hey Pete, I tried your suggestion with the fuel pressure gauge taped to the windshield, pressure was unstable, never got close to 40 psi often a lot lower. I'm going to replace the pump. With the high mileage on this vehicle I consider that a good start.
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Be sure to install a new fuel sock on the pump too. They are sold seperately, so don't forget to ask for it.
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Joined: Jul 2007
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From: Tallahassee Fl
I pulled out the pump and the fuel sock/strainer was so bad I put on a new one, siphoned all the fuel, wiped some minor sediment out of the tank and put the old pump back in. What the heck, I just had to see if that changed anything. Pressure is now between 35 lbs & 39 lbs and holds while driving around the neighborhood, much different that my previous testing. My Helms manual says it has to be 40.5 lbs, but my Haynes manual says 35 lbs is OK. DUH?
