I would hope that once you get your fuel to stop perculating near the exhaust, you may enjoy a surprise in Performance & Mileage! Any way to check the Air/Fuel ratio before any changes are made? Borrow a sniffer from a FLAPS or have a shop you trust check it? Is there an Oxy sensor in the exhaust giving a false reading? ($15) Can you tell I only know jack about Hilborn FI?
Since that looks like a fairly simple pipe, if relocating the pump & lines is too hard/expensive you may wanna wrap the exhaust in header-tape. It shortens the life of the ex-pipe, but may be a simple enough solution if the pipe is easy enough to take off & duplicate now. So you have a spare when this one goes bad 2 winters from now! If it's an expensive bit, forget this idea.
Exhaust wrap is my least favorite move, but some guys insist I install it on Hi-Po bikes builds. Yes, it flows better, usually, but by the time you find a leak, the metal pipe flakes apart as you unwrap it!
I've also learned that sometimes... when people don't agree with you .... its best to hold them down and kidney punch them till they agree with you
Last edited by hutch1200; 07-05-2013 at 10:22 PM..
Reason: add pR0n link
Ok so my problem came back the first time I went on a semi-long trip. After about 50 miles the jeep died. I have re-routed my fuel lines, replaced my fuel filter, fuel pump, ignition control module, coil, cap, rotor, plugs and wires. I am officially extremely stumped. The 350 is out of a 1995 Chevy 1500 according to the number on the block. Any ideas??
Here is my two cents, have you loosened your gas cap when you shut down? If it whooshes when you loosen the cap you probably have a fuel canister issue. If its plumed correctly (per Howells instructions) replace the filter on the bottom of the canister, its a couple dollars at Autozone or someplace like that.
Or you may have air en-trained in your fuel. The pump recirculates the fuel and it goes back into the tank, however it is dumped at the top of the tank and it can capture air. Think of a sink faucet aerator this can cause your pump to cavitate.
To check for this put one of those cheesy clear glass fuel filters on your return line close to the TBI take out the filter element and watch the flow of gas in the return line. If its clear when it shuts down you have eliminated the problem, if it looks like it has air in the fuel drop your gas tank and add a rubber hose to the return nozzle on your fuel sending unit so that the fuel return to the bottom of the tank you may have to weight the hose to make it sink to the bottom. This will give you the opportunity to tighten your suction line hose clamps, since a little vacuum leak can also get air into the system.
The fuel filter before the pump is a good idea I have one on my setup except it is much larger so there isnt as much pressure drop.
I have tried removing my fuel cap each time I run into a problem and there is no 'woosh' and it doesnt seem to help the issue. I have an inline fuel filter right before the pump and it is also new. It appears to be heat related because it only breaks down in the heat of the day. All my lines have been inspected for bad spots and have been moved from any hot spots.
Wrong pump you need a Walbro (check the Howell site)or equivalent capable of about 40 PSI even though the TBI only requires 11-13 PSI.
You are probably cavitating the pump by not pushing the fuel through the entire system the way it was designed.