I've stopped the pain & the expense!

60biscayne · #1 (**permalink**) 08-31-2008, 09:47 AM

Its been months now that I've been trying to obtain this 49.2 +/-2 (ie: 50) reading for the fuel pressure on this 2004 vintage 4.0 engine that I put into my '89 YJ. We started out with a stock '89 fuel tank that has no pump
Soooooooooooooooooooooo the easy way to obtain the pressure needed by the "New" motor was to procure & install a late 80's vintage Big Ford Truck fuel pump which is an external (mount on the frame rail) unit at a cost of around $50 I guess Thannnnnnnnnnnnnnnnnnnn we need to cut back the 100+ pounds (too much pressure) that this pump puts out plus this pump is making a funny noise which the mechanic says is because this pump is straining and can't suck the fuel as fast as it pushes it out Sooooooooooooooooooooo I than procure for $150 a 1994 Wrangler 19 gallon fuel tank that has the stock fuel pump in it that puts out like 35 pounds (not the 50 the New engine specs calls for) which will provide the input flow that the Big Ford Pump is yelling for etc.
Thannnnnnnnnnnnnnnnnnn we than procure a Filter / Regulator set-up for around $50 that is used on a 1998 Grand Cherokee and is suppose to cut back on the 100 pressure being fed by the Big Pump & giving us the 50 pounds we need - Hopefully! This Cherokee set-up mounts to the frame rail and doesn't work at first because it has a return line to the tank & the "New" engines fuel rail does not have a return line
Sooooooooooooooooooooo we plug off the return line at this filter / regulator and the engine runs buttttttttttttttttttttttttttttt its got like 90 pounds of pressure??????????? Soooooooooooooooooooooo we purchase on eBay an adjustable fuel pressure for around $70 and put it on after 2 weeks of hastle because they don't send any info with this thing etc....... (Japanese Junk!) anyway, this unit doesn't function so I return it & they send me another one which also doesn't function (maybe its me but my mechanic is a true expert and he can't get these things to function either
Soooooooooooooooooooooo my daughters boyfriend gets me a Super Duper Unit (probably costs over $400, it cost me $25 just for fittings to hook this thing up) that is used on these Foreign Race Cars like in the fast 7 the furious & now we adjust it to 50 & it runs great for a while than it won't run.... play with the adjustment ... now its OK thannnnnnnn Crap etc............
I go to this little Junk yard - there's a 1991 Cherokee wreck sitting there - it has a 4.0, the fuel rail with a return line & the injectors are sitting there............. I pull it all off - give the guy $5 for the stuff & take it to the garage.................
We disconnect the Fancy Adjustable Fuel Pump, the Grand Cherokee Fuel Filter / Regulator, the Big Ford Fuel Pump and hook up the junk yard stuff with a return line to the tank which has a '94 Fuel Pump in it and it runs like a dream!
End of story unless somebody wants to buy some of these lightly used high dollar value things that I have left over................

currupt4130 · #2 (**permalink**) 08-31-2008, 10:29 AM

I see your problem. You didn't tee off the return line into the exhaust collector, which would have lowered the initial pressure of the high velocity ultra sonic highly combustible liquid to a precise 57.78psi. Then you would have had to drill two holes under the passenger seat and put a banjo in place of the line so you aerate the fuel while getting some good West Va twang in the cabin. Then all you're have to do is tap the neck of the banjo with an AN-5, coil it 7 times around the heater coil to bring the pressure back up and tap it back into the fuel rail. That would have been so much simpler...