You are here:
- Home
- Industry
- Transportation and Logistics
- Automotive
- 1988 Ford F-250 P/U 5.1/351v8
Automotive/1988 Ford F-250 P/U 5.1/351v8
Advertisement
Question
Ernie,
Have a 1988 ford f-250, dual gas tanks, When the outside temp. reaches 100f or more, as it often does in tucson az,the engine appears to starve for fuel when it gets hot, or sits for bit while running errands,then it sputters & dies. Let it sit for bit, switch tanks, yell, curse, sweat... and of you go, for a while anyhow... Replaced high pressure fuel pump, replaced switching valve etc... fuel filter, alternator, volt reg, battery, could both in tank fuel pumps be bad ??? To my knowledge they have never been replaced. Engine was replaced +/- 40k ago. Vehicle receives regular maint. Any ideas ??? When the weather cools off, the problem goes away.....
Respectfully,
M.J.Castoro
Interestingly, we have a region here in BC that is known by many travellers as being a place for an unexpected coffee stop. Hedley is a little town that, in addition to frequently getting to 100F or more in the summer, is in the bottom of a valley. Cars descend a long hill into town, slow to town speed for several blocks to pass through, and then face a long climb out of town again.
Often ... very often ... engines will sputter and shut down. The advice most travellers will get (from the cafe owner) is to have a coffee and try some of the pie, etc, and just wait for a bit. Half an hour later, the cars can be restarted with no problem, and the parties leave knowing one more coffee stop along the highway.
My wife's two different minivans each were stalled in that town over two different trips through that town. My E250 has been through there too, several times, but never with a problem. My van, however, being subject to a lot of custom re-engineering, is not quite as originally manufactured. Its major benefit, insofar as avoiding being stuck in hot valleys is concerned, is some simple rerouting of the fuel line from its original path near the block of the engine.
When I refitted my 351W with a four-barrel manifold so as to upgrade it to a vacuum-secondary emissions-calibrated Holley 4160 (to improve both city economy and highway performance), I made new fuel delivery lines for the engine compartment. My lines follow mainly straight lines and ninety-degree curves, and are some inches ahead of the engine. This was in part to open room for a secondary fuel filter and a pressure regulator, and in part to make sure that the line would be removed from the immediate vicinity of the block and its radiated heat and in the slip stream of cooling air coming into the engine compartment. In that way, I hoped to avoid any vapour-lock scenarios ... and I have!
Gasoline has very high vapour pressure at normal ambient temperatures, meaning that it readily evapourates to gas phase. Gasoline easily vapourises in overheated fuel lines, essentially lowering the density of fuel arriving at the carburetor or injection system to a tiny fraction of what is needed to keep an engine running.
Sorry for the long story; its purpose was to illustrate how common a problem this is. The fix, happily, is very easy. Bend new fuel lines from standard stock, shaped and positioned so as to be limit their heating by the engine and to maximise cooling by incoming air.
Good luck ... EGK
Related Articles
Answers by Expert:
Ernest (Ernie) Kenward
Expertise
The challenges I most enjoy are thoughtful technical questions of a trouble-shooting nature in both electrical, power electronic and mechanical systems, mainly automotive but also machine control and small-machine PLC applications. Please note, however, that I am NOT a walking shop manual! I DO, however, make it a point to have those manuals and other service literature for those vehicles I DO own, and highly recommend that anyone serious about maintenance or modification of their vehicles do the same; MOST of your answers WILL be found there. For that matter, I do NOT go out of my way to acquire shop manuals for any vehicle I do NOT own! That being the case, any general query to me along the lines of "What is the meaning of this code read from the ECU of my 2015 XYZ?" or "Where is the fuse for the windshield washer pump found?" (try your car's electrical distribution panel for a start!) will not go far. What I do offer is a pretty good collection of literature, insights and hands-on experience with 1950s to 1980's Ford products (plus a developing database of information and practice with the Mercedes diesel cars), along with an engineering perspective and the ability to design and implement custom control, electrical and mechanical subsystems for vehicles. For that reason, I am happy to make my thoughts and efforts available to those who are of like mind and/or are seriously making a point of learning about their vehicles. Use the Opportunity to Learn!
Experience
A key skill in my work and hobby pursuits both is STRATEGIC TROUBLESHOOTING. I am a senior instructor in Electrical Engineering Technology at a leading Canadian polytechnic, my areas being Electrical Power and Industrial Control, electrical and electronics design and manufacturing, and AutoCAD and related CAD/CAE software - plus equipment problem-solving and new equipment design and prototyping.
Hobby-wise, I have 30-plus years of experience in auto restoration, mostly in electrical and mechanical systems. Ongoing projects include a 1959 Edsel Corsair, my 1978 Ford E250 class-B motorhome conversion, and the care and upkeep of my Mercedes 300CD.
My vehicles become engineering test beds for electrical and mechanical upgrades as ideas present themselves. This includes the design and production of circuit boards to restore or enhance features for which no OEM replacement parts are obtainable, or where better specifications or reliability can be had via newer concepts. Regarding the E250 RV conversion, I designed and continue to revise a custom power distribution system, managed by a Programmable Controller (PLC); this has made most revisions as easy as uploading new firmware as I develop it.
The "mini" PLC is a powerful device for custom automotive control systems. One good example (there are many) would be the Moeller "Easy Relay"; these offer a wealth of control, monitoring and variable-and-status display options for such projects. A good example project which has worked well is that one for my RV noted above, which has been on the job - revised in firmware only - for a decade now. It is a load management and charging control system to avoid the sulfation-induced early failure that often befalls deep-cycle batteries used in RV power applications. The battery installed in 2003 lasted long enough to more tnan pay for the PLC that contributed to its longer life ... and the PLC will be there for the next battery as well!
Organizations
IEEE - senior member ... past WCC Student Activities;
SME - senior member ... past chair, greater Vancouver chapter chair 318;
Edsel Owners' Club - have served in various capacities on chapter executive during seventies;
have been Power and Driveline resource on the Edsel Owners' Club "E-team" for more than a decade.
Education/Credentials
Graduate of UBC
Awards and Honors
Certificates of appreciation from IEEE and SME for work in student and chapter activities
©2012 About.com, a part of The New York Times Company. All rights reserved.