EFI troubleshooting (1 Viewer)

[Kynot62]

Anyone who has worked on their EFI knows that a pressure gauge is an integral part of troubleshooting. But after checking on the price of one (about $250 for a quality unit made by OTC with the fittings to hook up to my 3FE) I came up with a cheaper alternative.

I just bought a cheap generic fuel pressure tester with a 0-100 psi gauge and about $10 worth of hardware. Total cost was under $50

The only tricky part is making the banjo bolt to go into the cold start injector. I drilled the center hole on my lathe and the two holes through the side with a drill press. (see photos) Just remember that one of the side holes goes through the existing injector fitting and the other comes out in the "T" to feed pressure to the gauge.

1 - 1/4 in "T"
2 - 1/4 in plugs
1 - 1/4 x 1/4 (pipe on one end, flare on the other)
1 - 8mm x 60mm bolt (1.00 pitch)
1 - copper washer

The flare fitting hooks up to the gauge (that I didn't take a picture of) and sorry I don't have photos of it hooked up. I will probably hook it up again this weekend as I am still working on an engine gremlin and I will snap a photo to post.

But it worked great and I still have money to spend on my wagon!

Tony

 

[slcfj62]

Very cool. Any suggestions for those of us that don't have a metal lathe?

 

[Kynot62]

You should be able to do it with a hand drill or a drill press just go slow and dont let the bit wander. The hole in the center is only about an inch deep. And the hole doesn't have to be perfectly centered, it's only there to let fuel pass through it. I matched the size of the holes to the existing ones in the factory bolt by the way. Center hole is a #32 bit and the side holes used a #41. Hole through the "T" is a 5/16 which is just about dead on for an 8mm bolt.

Tony

 

[slcfj62]

Where the bolt with the hole up the center sticks out the bottom of the "T", how did you seal around it so fuel doesn't come squirting out? It doesn't look like it is threaded.

 

[Kynot62]

I used the copper washer from the stock bolt. No there are not any threads, the bolt just slides through it, just like it does with the banjo fitting on the stock fuel line. When this fitting is installed there are 3 copper washers that do the sealing one under the banjo fitting one between the banjo and the "T" fitting and one under the bolt head.

Tony

 

[Kynot62]

Here are the pics I promised with the gauge plugged in to the fuel system at the cold start injector. It doesn't show very well but there is 40psi on the gauge and no leaks. Now the earlier pics should make more sense.

Tony

 

[slcfj62]

That thing is totally awesome. Did you source your parts locally or over the Internet?

 

[Kynot62]

The gauge came from the local auto parts store as well as the fittings and the bolt came from ACE. All the brass fittings should be available from any plumbing supply, home depot, hardware store, etc.

Tony

 

[ntsqd]

First time seeing this, linked from the Home Made SST thread.

One way for the bolt to be made without a lathe is to file two large flats on the bolt opposite of each other. Volume flow is not crucial here, so if the flats are big enough there won't be a significant pressure drop and the fuel can still get to the cold start injector and the pressure gauge. Ultimate bolt tension isn't a concern either, so the missing thread sections aren't a problem.

 

[rfj62]

Hey Tony, feel like making any of these and selling them to folks that don't have a drill press or a steady hand (like me)? Might be worth it for both parties.

 

[PF]

Here is an alternative solution. It's a Harbor Freight pressure test kit with some hardware from BelMetric.com. The pressure test kit costs about $20 on sale and is part no. 92699. I was a little skeptical of the harbor freight gage so I checked it against some calibrated gages we have at work. It was within 1psi. Good to go. From Bel Metric I ordered a double banjo bolt, banjo fitting, fuel hose and a bunch of copper washers. Works like a champ. Assemble as shown in the photos.

Even with 245k miles on the pump, fuel pressure is still up at 46psi on the 3FE. Fuel system is good. Now if I could only figure out what's really going wrong with my truck.