The other day I was driving home on the freeway, started going up a small hill and just started losing power. I barely made it home. Next day car started right up and would idol, but when I tryed to drive, it had no power and died! So, I did a fuel presure check, here are my readings.

At fuel filter:
Power On. 80 psi.
Levels out at. 78 psi.
Leakdown.
At 1 min. 75 psi.
At 2 min. 73 psi.
At 10 min. 65 psi.

At Schrader vavle:
Power on. 60 psi.
Levels out at. 54 psi.
Leakdown.
At 1 min. 30 psi.
At 2 min. 15 psi.
At 5 min. 0 psi.

Pump looks good, but obviously somethings wrong after the fuel filter! How do you know what's leaking in the plenum? If I was losing any presure at the filter or any of the fittings would they be leaking gas?

I have the 95 with the aluminum intake and the horizontal D-Cap. W vin.

 

The excessive leakdown is inside the plenum. Very common for the lines to and from the injector assembly, and or the fuel pressure regulator to sprout leaks. Once the plenum is off, turn the ignition to the RUN position, (don't try to start the engine) and look for leaks. The pump will only run for ~2 seconds, and you need to look for leaks during the time. Post your results.

 

Thanks captain! Won't be able to get to it untill this weakend, but will do what you said. Just so I'm clear, can presure leak out anywhere without fuel leaking? ie. fuel pump or any of the fittings? Also, how do you tell if the poppits are leaking?

 

No. The entire system, except for the return line, is pressurized and can leak fuel while the pump is running, and until pressure is relieved. The return line can leak fuel while the engine is running, and for a short time after shut down. The fuel pump can leak in the tank, but in your case, it's not leaking.


Best way is to pull them out of the intake, and watch them while the pump is running. A leaky poppet could be the cause of your excessive leakdown. If there are no visible leaks with the plenum removed, it's either a poppet, or the fuel pressure regulator is leaking internally. There's a test for determining if the regulator is leaking, but for what it's worth, it's easier to pull the poppets out and look them. If they are not leaking, it's the regulator

 

Where is the return line located in the plenum, and if it's leaking, how would I know? Also, would it cause my leakdown? Is there a sequenc for removing the plenum, and what's the tourque presure and sequence for putting it back on? Just want to get my ducks in a row, so I know what to look for when I pull the plenum. Thanks

 

There's a combination of 10 bolts and nuts that hold the plenum in place. Pretty sure they are 10mm. Throttle cable, and some other minor things must be removed as well. You will need to replace the gasket, fuel lines, which are commonly referred to as the "nut kit", (no idea why) and probably a good idea to replace the injector electrical connector. With the plenum removed, ignition in run position, engine off, if there are any leaks, you'll see them. You might notice an amber or gold color where the fuel has 'washed" the area clean. If the regulator leaks, it will be "washed" on the passenger side. If the lines leak, it will be on the driver side.




This is what you'll see with the plenum removed:




Here is a link to the lines:
Dorman - Help Cmfi Fuel Injector Feed And Return Line 55163: Advance Auto Parts


Here is a link to the gasket:
Advance Auto Parts: Search Results for plenum gasket set


Here is a link to the electrical connector, and it must be soldered to the harness, NO crimp connectors allowed:
CARQUEST by BWD Fuel Injector Connector 28413: Advance Auto Parts

 

If one of the poppets is leaking, can I replace just the one, or do I have to replace all of them? If the nut kit isn't leaking and it's just the regulator, do I stiil need to replace it? Same with the electrical connector? I'm on a real tight budget, so I can only afford to do what I have to, but I do want to do it right, so I don't have to do it again! I was going to work on it this weekend, but a big storm came in tonight, we're going to get about 8in. of rain over the weekend, and the car is outside, so it will have to wait untill Monday!! I really need to get it done, I think my family and friends are tired of giving me rides!I'll keep you updated as I go!

 

If the regulator is leaking, you can replace it seperately. If the injector, spider line, or poppet is leaking, you must replace the entire injector assembly, (the regulator comes with it). If you end up replacing the injector assembly, replace the nut kit at the same time or it will leak. The electrical connector should be replaced as preventitive maintenance. When you get in there and start moving things around, the connector and or wires usually break.

 

OK, theres a small break in the weather, so I'm going to get at it! One last question before I start. What shoud I use to clean the inside of the plenum, ie. Carb cleaner, Break lean, Throtal body cleaner, or something eles? Also, Should I try to clean the poppets, and the spider, or should I just let them be?? Thanks again for all the help!!

 

Any of those will work to clean it up. You can spray the tips of the poppets, but don't expect it to do much. They problem is the ball and orifice clog up, and you can't get at them to clean them. They would need to be professionally cleaned, and the cost for that is darn near the cost of a new injector assembly. If it doesn't work, you've already spent the money, so you're better off replacing it from the start.