A question on injection types. Cleanliness vs longevity

[MaverickMan]

So this manual only on the 2.3 issue has brought alot of people drawing lines on injection types.

Disclaimer, I am an old skool guy, the only two fueling methods I would ever recommend or setup myself is Webber or Demon. I have even flirted with mechanical injection. However like the rest of us I aquiesce to modern fool injection.

My question is based purely on long term ownership, you resellers and folks who plan to rack up 300,000 in the next few years and then junk it arent really the focus here as you will not have this Bronco in the year 2045. If we even have fuel or a rock to stand on by then.

I am concerned not about carbon build up, because that seem to be able to be mitigated by a catch can, something I havent really researched as to why other than accepting the loudest of opinions. I am worried about plumbing. So you have a 6 cylinder with direct and port injection. That means 12 injectors of 2 types, and 12 or more connections on top of the engine. Then you have regulators is there one for each injector type? how many connections does that add? Are all the injectors on rails? How many rails are there or do the injectors have individual lines and a manifold. Is there more than one pump? Is there a supplemental pump after the low pressure line peels off? How many fuel connection points do we have on top of our hot modern turbocharged engine? Will these connections fail or leak in 10, 20, or 30 years? Is there a schedule for O-ring replacement at 150,000 mile intervals?

I know that modern connectors and fasteners are vastly improved over rubber hose and clamps or even manual flared lines. But as a old skool carb guy I know how quickly a leaky fuel line can cause a really bad day and thats with maybe 3 or 5 connections under the hood, 7 at most. Yes moder connectors will be better and more resilient, but we take our Broncos off road, though dust, mud, sand, snow, and water. Up and down mountains(altitude) over and over again.

Will the myriad of fuel connectors cause problems for us a couple decades down the road? And will the simple math of halving only one fuel system be better in the long run provided we keep our cylinders clean?

Just a thought for us long haulers. Which I realize is not the norm. But Im gonna be buried in my Bronco, probably in mud!

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[The Pope]

Very good questions.

I have my opinion, but I'll wait for others to chime in before I do, as I'm pretty set in which fuel injection setup I want.

 

[Economisto]

Was wondering the same

 

[Bmadda]

All DI systems use 2 pumps. A regular in tank electric pump, and the high pressure pump mounted to the head. The 2.7 would simply supply port fuel directly from the electric pump to the port fuel rails. Only the DI injectors get fed from the DI high pressure pump. Ford has not used regulators for many years...all the systems now are returnless. Pressure is controlled by duty cycling the electric pump. The computer uses a fuel rail pressure sensor (FRP) to control fuel pressure closed loop style (to the low pressure rail). High pressure fuel is controlled by engine rpm and is purely mechanical (like old diesels were)

 

[MaverickMan]

All DI systems use 2 pumps. A regular in tank electric pump, and the high pressure pump mounted to the head. The 2.7 would simply supply port fuel directly from the electric pump to the port fuel rails. Only the DI injectors get fed from the DI high pressure pump. Ford has not used regulators for many years...all the systems now are returnless. Pressure is controlled by duty cycling the electric pump. The computer uses a fuel rail pressure sensor (FRP) to control fuel pressure closed loop style (to the low pressure rail). High pressure fuel is controlled by engine rpm and is purely mechanical (like old diesels were)

Interesting, sounds more like one and a half fuel systems. Thats not too bad. Hopefully the associated plumbing is simple.

 

[Bmadda]

Interesting, sounds more like one and a half fuel systems. Thats not too bad. Hopefully the associated plumbing is simple.

Virtually all of it is located under the intake manifold. DI pump mounts rear of RH cylinder head. I'm basing all of this on F-150 shop manual pics btw...most seem to think few if any changes are going to be made for Bronco. Biggest concern I have (and for the record I'm a 2.3 buyer, so I'm prepping myself for when I see customer trucks w/these), is diagnosing a bad fuel injector. The book makes it sound like it doesn't use both sets of injectors at all times. Uses PFI at idle, and low speed, DI for high speed. Shop manual states a scan tool can be used to isolate either system. Never been involved...so if there's somebody reading this who has had to diagnose a bad injector on one of these feel free to educate me?

 

[mneblett]

I'm closing in on 50 years playing with carbs, Bosch mechanical fuel injection and current DI and port injection systems (in fact, this afternoon I have to go clear a stuck float valve on a BMW motorcycle carburetor). We currently have an F150 and a Mustang with dual DI/PI systems, and we keep our vehicles typically for ~10 years.

I have 100% faith in the long-term reliability of dual FI systems. FWIW, I'm an engineer by training and do work in the field. The piping for the high pressure side is all metal tubing (circa 2000 psi -- hose connections in the high pressure system are not an option). The port injectors are on conventional rails, and unlike carb-era rubber lines, the few short sections of flexible line are damn-near bullet-proof (as they should be after three-four decades of use in millions of FI engines). As of 2020, both DI and PI systems have tens of millions of miles of experience in all sorts of real-world environments, and connection failures are virtually unheard of, even with 25-30 yo PI systems. The #1 problem with FI is not connections or regulators, its clogging of injectors -- something that is/will be no different with dual systems.

Dual FI systems are the best of both worlds for performance (power and emissions) and valve cleaning. If I can help it, I won't buy another vehicle without a dual DI/PI system.

 

[MaverickMan]

I'm closing in on 50 years playing with carbs, Bosch mechanical fuel injection and current DI and port injection systems (in fact, this afternoon I have to go clear a stuck float valve on a BMW motorcycle carburetor). We currently have an F150 and a Mustang with dual DI/PI systems, and we keep our vehicles typically for ~10 years.

I have 100% faith in the long-term reliability of dual FI systems. FWIW, I'm an engineer by training and do work in the field. The piping for the high pressure side is all metal tubing (circa 2000 psi -- hose connections in the high pressure system are not an option). The port injectors are on conventional rails, and unlike carb-era rubber lines, the few short sections of flexible line are damn-near bullet-proof (as they should be after three-four decades of use in millions of FI engines). As of 2020, both DI and PI systems have tens of millions of miles of experience in all sorts of real-world environments, and connection failures are virtually unheard of, even with 25-30 yo PI systems. The #1 problem with FI is not connections or regulators, its clogging of injectors -- something that is/will be no different with dual systems.

Dual FI systems are the best of both worlds for performance (power and emissions) and valve cleaning. If I can help it, I won't buy another vehicle without a dual DI/PI system.

Fuel lines under the manifold and tucked away from harm and the pump being very close to it. is all great. I hope the lines themselves are of a high quality anti corrosion type. The common rail low pressure idle injectors may be the weaker link in the plumbing area, I imagine that you just cause poor idle conditions something that alot of 80s and 90s FI vehicle suffer from. So that should be something to live with for a moment then fix as fast as can be diagnosed. Im talking in 20 years when nobody at the shop wants to dust off the 20 year old scanner equipment the old guys used to use lol. As someone who exclusively buys older vehicles(until the bronco), Old stuff will always have get fixed, used to be a few wires and hoses and a couple lines and alot of useless vaccum lines. Then it was wires galore, relays, fuses, and 3 or 4 computers as powerful as a casio watch. Along with a few high pressure lines with crumbly plastic clips holding them together. Now its big computers, wiring busses, pumps and resevoirs everywhere. And a whole lot of plumbing for everything. But alot of it looks like the parts come with all their pigtails and lines. I just hope in 2045 someone wrote all this stuff down today so I can find it then. Thanks for the detailed insight.

One more question, do you think I will be able to adapt a predator carb on these engines?

 

[MaverickMan]

I do plan on getting to 300,000 miles with it. I sure as hell better for 40,000. Any less the 200,000 miles with offroad abuse would be pathetic. My 96 just got up to 200,000. Yeah its a SBF and they last forever, but I hope these are built close to that reliability.

 

[dwbronco]

Very good questions.

I have my opinion, but I'll wait for others to chime in before I do, as I'm pretty set in which fuel injection setup I want.

Why wait? If you know something or have an opinion, why does it matter what others have to say?

 

[stedydrizl]

I'm closing in on 50 years playing with carbs, Bosch mechanical fuel injection and current DI and port injection systems (in fact, this afternoon I have to go clear a stuck float valve on a BMW motorcycle carburetor). We currently have an F150 and a Mustang with dual DI/PI systems, and we keep our vehicles typically for ~10 years.

I have 100% faith in the long-term reliability of dual FI systems. FWIW, I'm an engineer by training and do work in the field. The piping for the high pressure side is all metal tubing (circa 2000 psi -- hose connections in the high pressure system are not an option). The port injectors are on conventional rails, and unlike carb-era rubber lines, the few short sections of flexible line are damn-near bullet-proof (as they should be after three-four decades of use in millions of FI engines). As of 2020, both DI and PI systems have tens of millions of miles of experience in all sorts of real-world environments, and connection failures are virtually unheard of, even with 25-30 yo PI systems. The #1 problem with FI is not connections or regulators, its clogging of injectors -- something that is/will be no different with dual systems.

Dual FI systems are the best of both worlds for performance (power and emissions) and valve cleaning. If I can help it, I won't buy another vehicle without a dual DI/PI system.

I have been trying to stay away from DI because of all the issues with maintenance and added problems. I bought my 2016 5.0 coyote because it was NOT DI. Can you tell me what maintenance should be done to keep the 2.7 problem free ? I have only ever ran Red Line in my trucks at each oil change and never had any issues with dirty injectors, codes thrown of even poor performance. I understand from Dealer, that should not be expected on 2.7.

 

[mneblett]

I have been trying to stay away from DI because of all the issues with maintenance and added problems. I bought my 2016 5.0 coyote because it was NOT DI. Can you tell me what maintenance should be done to keep the 2.7 problem free ? I have only ever ran Red Line in my trucks at each oil change and never had any issues with dirty injectors, codes thrown of even poor performance. I understand from Dealer, that should not be expected on 2.7.

DI-only is precisely the reason Ford (and others) are going to DI/PI systems. DI-only results in trouble-causing carbon deposits to build up on the valve stems because there is no gasoline in the incoming air stream to wash off the nascent deposits (Google for pics of build-up). Going to port injection restores this washing effect. The addition of PI is intended to eliminate the poor running starting at 40-50K miles with DI-only engines, so no "special" maintenance should be needed. The only thing I'm going to do is the same thing I've been doing for years in all my vehicles -- an occasional dump-in of Techron to clean the injectors.

TL,DR: The concerns with the previous DI problems arising from gummed-up valves should not be applied to the current DI/PI systems. The "DI problems" concern should not be a cause of worry where the underlying cause has been addressed.

As I noted above, given the choice, I won't buy a DI engine without PI.

 

[MaverickMan]

DI-only is precisely the reason Ford (and others) are going to DI/PI systems. DI-only results in trouble-causing carbon deposits to build up on the valve stems because there is no gasoline in the incoming air stream to wash off the nascent deposits (Google for pics of build-up). Going to port injection restores this washing effect. The addition of PI is intended to eliminate the poor running starting at 40-50K miles with DI-only engines, so no "special" maintenance should be needed. The only thing I'm going to do is the same thing I've been doing for years in all my vehicles -- an occasional dump-in of Techron to clean the injectors.

TL,DR: The concerns with the previous DI problems arising from gummed-up valves should not be applied to the current DI/PI systems. The "DI problems" concern should not be a cause of worry where the underlying cause has been addressed.

As I noted above, given the choice, I won't buy a DI engine without PI.

Boost coolers like Snow Performance and the like would help wash the valves too right? That would be a win win on added performance. A DI 2.3 with a boost cooler and a Ford tune should match the 2.7 performance if not exceed it along with making it more reliable and cooler running atleast in the cylinders? How about nitrous?

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