Brad Clayton Posted August 25, 2011 Share Posted August 25, 2011 Well actually, I have never been down this road at all. Had the heads off an '05 and when I put it back together I couldn't get the fuel system to prime up the heads. She was dry for sure, but i never had a problem in the past. I actually had to remove the plugs out of the back of the heads and run the koeo until fuel flowed out. Quote Link to comment Share on other sites More sharing options...
Mikill Posted August 26, 2011 Share Posted August 26, 2011 I have had success blowing shop air into the fuel tank to help push the fuel up to the filter housing. Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted August 26, 2011 Share Posted August 26, 2011 I've had some success in the past with periodically removing the fuel filter cap to let the air out. I've also had to try the shop air in the filler neck trick. It doesn't happen too often, but when it does it can be a pig. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted August 27, 2011 Share Posted August 27, 2011 IMHO, there is NO WAY a good FP should struggle to prime the system in a couple of seconds. This should be a red flag your FP is retiring. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 27, 2011 Share Posted August 27, 2011 I'll tell ya Bruce, there have been numerous times when I have replaced fuel filters in an F-series 6.0L that I cycled the key 5 or 6 times to prime, only to have the truck start and make it just out the shop door with an air locked fuel system. A quick crack of the secondary fuel filter cap with a "pssssst" and a few more cycles of the ignition and all is well. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted August 27, 2011 Share Posted August 27, 2011 OK, agreed, I've seen this before, too, but I still maintain that if this is the case the FP or regulator (probably the pump) is compromised. One of the things I teach in class is how important fuel return flow is. If the pump is strong, there will be considerable return flow, probably between a pint and a quart (measured by removing the return hose at the tank) in 30 seconds. If the pump is weak, return flow will be the first thing that suffers even though pressure still meets specs. It is very common for a FP to meet pressure specs but not have sufficient return flow. On a good vehicle with an electric pump, (this can be either gas or diesel) when the key is turned on and the electric pump is energized, within about two seconds the entire pressurized system is flushed of warm fuel and cool fuel is fed through, and returned to the tank. My opinion is unchanged. If the FP does not immediately prime the system, it is likely the FP flow is weak. If you measure return flow this will be identified. This is also a great test to diag/verify clogged screens in the 7.3 pickup assy. You've never seen a weak FP on a 6.0? Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted August 27, 2011 Share Posted August 27, 2011 IMHO, there is NO WAY a good FP should struggle to prime the system in a couple of seconds. This should be a red flag your FP is retiring. +1 (with some reservations over the couple of seconds part - certainly cycling the fuel pump for three of it's 30 second key on phases should be more than adequate)... or a posssible air leak on the suction side of the pump. By this point in time, we should all be aware of the need for adequate fuel pressure on HEUI systems - 310-093 turns this into a 5 minute job that should (IMHO) be included as part of any engine work based on driving performance issues. And it is a quick way to pick up between .3 and .5 in a righteous manner. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted August 27, 2011 Share Posted August 27, 2011 OK, I surrender on the time base. Also, if it is a gasser with returnless this obviously does not apply. IH just went to electric pumps on their engines this year and I'm curious what we'll see with them. They are in an aluminum housing attached to the FF up front on the engine, which is not a great place for an electric pump (pull vs. push). Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted August 27, 2011 Share Posted August 27, 2011 Interesting you should mention "pull" pumps versus "push" pumps. I know a lot of guys that can't deal with the differences and what considerations are different. What helped for me initially was being on the fire department - it was rare for us to have to draught water but it was a technique I felt I had to master. In later years, this helped me solve a concern on a 1939 Dodge Businessmans Coupe (sadly, this piece of automotive history was lost in May, 2011 - among so many other examples) that involve a rusted through fuel line above the rear axle. "Suck" pumps are spendy. "Push" pumps aren't. Not sure why but I gather it is because of tolerances and quality control Many youngsters feel that Bernoulli and Venturi are just a couple of old Wops and why would we need to know that shit anyways? Remember Fords early EFI efforts? The ones with a lift pump in the tank and a pressure pump on the frame? Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted August 28, 2011 Author Share Posted August 28, 2011 Quote: IMHO, there is NO WAY a good FP should struggle to prime the system in a couple of seconds. This should be a red flag your FP is retiring. Oh I agree with all that is said about it and it did cross my mind but the customer was not interested in pursuing it. Hell I couldn't get a customer to buy a rad in a 6.4 yesterday, and it was pouring out. He was in for a mil and wanted to know how I knew the rad was bad. I pointed him to a visual inspection being the first thing his money buys. Quote: Remember Fords early EFI efforts? The ones with a lift pump in the tank and a pressure pump on the frame? Never was a fan, almost lost my job over a diag on one of those and it was a correct diag. The sm was a hot head. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted August 28, 2011 Share Posted August 28, 2011 The ones with a lift pump in the tank and a pressure pump on the frame? My fondest memory is of one that another shop put 2 or 3 secondary pumps on that lasted only a few weeks 'cause they didn't know there was a primary pump. Yea, I remember those POS. They made me buy a ProLink IBOB (intelligent breakout box) which took raw data from the PCM and gave you data stream through the scan tool, but only after you hooked it up. I'm 6'5". Remember where the fucking PCM was on a Tempo? (For you young'uns, IIRC Ford made a PFI with no data stream from '85ish to '88 or '92 or something. What a frigging diagnostic disaster- no MIL, either IIRC) Talk about learning the hard way, being thrown into something like that. OBD2 is a frigging cakewalk in comparison, even the worst one you've worked on. Count the needle sweeps........ Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted August 28, 2011 Share Posted August 28, 2011 The no data stream was the big impediment... it feels strange calling this "old technology" after learning how to adjust breaker point dwell and polarize generators.... I remember spending a lot of money on an OTC Monitor 2000E and having the salesweasel tell me that this would be the "last scan tool I would ever need to buy". At that same time, GM featured limited data stream including block learn and integrator (think LTFT and STFT) and Dodge even had ATM (actuator test mode) which was a rudimentary form of output state control. Some of us dinosaurs managed to make the conversion from "simple" to "OMG". Others weren't so lucky... back then, there was no Walmart and thusly, no positions as Walmart Greeters so there was a big influx of truck drivers.... Ohhhhhh, that was nasty. The moral of this whole thread? Keep your fucking eyes open and expect the unexpected. During the mid to late 80s, a Ford pick up with an EFI 5.0 might have a shallow cup fuel filter, a deep cup fuel filter, two fuel filters, three fuel pumps, two fuel pumps... You would learn and prosper.... or you wouldn't. Quote Link to comment Share on other sites More sharing options...
blown99 Posted August 29, 2011 Share Posted August 29, 2011 OK, I surrender on the time base. Also, if it is a gasser with returnless this obviously does not apply. IH just went to electric pumps on their engines this year and I'm curious what we'll see with them. They are in an aluminum housing attached to the FF up front on the engine, which is not a great place for an electric pump (pull vs. push). I can tell you that even the slightest bit of inlet restriction will do these pumps in. This past winter, I replaced several out on the road due to slight fuel gelling. Outside of those incidents, I have yet to see any other issues.Mark Quote Link to comment Share on other sites More sharing options...
mrbudge Posted August 30, 2011 Share Posted August 30, 2011 Just remember pumps cannot pull, they only push. Atmospheric pressure pushes fuel into the pump. Not enough pressure in the atmosphere to overcome inlet restrictions. Quote Link to comment Share on other sites More sharing options...
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