Volvo's That Run Chapter 14 Fuel System

[TestPoint]

Chapter 14: Fuel System

For those converting a gas Volvo the primary and pressure pumps and the remaining Volvo fuel system setup will work without modification as long as you are using the ’96 –’97 Explorer engine. The Volvo / Bosch continuous injection system ran at a regulated 72 psi so the original system will meet the needs of the 5.0L stock engine as I am installing it. The new Volvo pump that I installed actually measured 95 psi dead headed into a gauge. The '96 - '97 model years used the long-term standard 41 psi injection system with a fuel rail mounted mechanical pressure regulator and a return line to the tank. Beginning in ’98 the Explorer dropped the fuel return line and the system was designed with an in-tank pressure regulator. Consequently, there is not a pressure regulator and fuel return line connection associated with my engine and the pressure required is not the 41psi but 65psi. An after market pressure regulator to dump excess fuel pressure back to the Volvo return line is required. I found an adjustable one, with a pressure gauge and mounting bracket on eBay of less than $20 shipped.

CAUTION: The pressure side of this system deserves special attention to connections. The Volvo Diesel hard line into the engine bay does not have a barbed or even a flared end. Mine blew off with a single solid fuel line clamp. I used a flare tool to add a very slight flair and the clamp added some semblance of a barbed connection and secured with a couple clamps. The gas Volvo fuel lines had flares and flare nuts. At that running pressure it will dump a lot of fuel quickly.



Since the Diesel car had neither pump but relied on suction from the injector pump I had to add an '83 and up bracket, pressure pump and filter as shown above. The floor pan had threaded mounting holes to match the bracket that were, of course, completely filled with rust proofing. I also installed a used tank lift pump and fuel sender from a local wreaking yard. See the electrical chapter for details on wiring.

The parent document for this thread can be found here: http://forums.turbobricks.com/showthread.php?t=250257

[M.H. Yount]

At the link below, I document my fuel system rebuild on a 5.0L powered 242. I put a Deatschwerks 300 L/Hr in-tank pump in it and will be doing away entirely with the stock fuel system. Running -6AN -- 3/8" size line front to back with a Russell 10-micron filter with replaceable paper element. You can follow along here....

http://forums.turbobricks.com/showthread.php?t=254914

[TestPoint]

I am going to see a local independent GM Master Mechanic tomorrow to try to determine what years GM used a 65 psi manual regulator. Apparently GM moved to 65 psi injectors about the time Ford did but did it for a couple years mechanically rather than with a PCM controlled fuel pump and sensor feedback.

Lesson for the day: If you are going to test your pressure regulator make sure that your fuel lines are connected to the fuel rail.

[TestPoint]

The GM lead was a dead end. GM used 58 psi compared to Ford's 65. I really wanted something that would look like an automobile manufacturer installed it. Not going to happen. I will hide it best I can.

Gave up and ordered a MALORY universal adjustable pressure regulator (MAL 4305M). It has a vacuum port and a port for a gauge. At least I can use one of the cheap regulators' gauges.

Later discussions regarding the use of the vacuum port came to the conclusion that it was not necessary since the '98 - '01 Explorer had the regulator in the tank and no provision for vacuum influenced additional fuel pressure under load. The assumption being that the PCM manages the injector pulse width to accommodate any higher fuel requirements.

The parent document for this thread can be found here: http://forums.turbobricks.com/showthread.php?t=250257

[TestPoint]

Sorry, double post. I probably found a way to do that.

[TestPoint]

. . . they wouldn't pay me so much.

While the Malory regulator appears to be a perfectly valid solution the fuel line connections to it have turned out to be quite an issue. The fuel in and return line start off with 8-AN connectors and I need to convert to 3/8" barbed for supply, 1/4" barbed for return. Nothing in plumbing, auto parts stores or on-line did that in a single piece. One creative parts guy did it in four pieces that was about 6" long.

Went to my favorite NAPA store (sure do miss the yellow and blue stools) and their hot rod specialist noticed that the AN connectors were the type used in hydraulic hoses. Found exactly what was needed in one or two piece solutions. The only problem was that the barbed connectors were buried inside the crimp sleeves. No problem that an air driven cut-off tool couldn't handle.



The large fitting is a NAPA part number 06U-606 that connects to the 8-AN regulator fitting and has a 3/8" hose end. On the smaller return side we replaced the 8-AN fitting that came with the regulator with a C5315 x 6x8 fitting and then added a 04U-606 hose end. Cut both crimp sleeves off and was done.




In hindsight, a more elegant solution would be to use the crimp sleeves to crimp the hoses to the engine and the return lines at the regulator rather than cut them off and use clamps. On the line to the fuel rail you would need to get the length right first then crimp both ends. The 'get the length right' part is probably why I used the clamps at the regulator. Maybe I will fix this little issue along with about a hundred other clean-up items on the list of 'things not done right the first time'.

The parent document for this thread can be found here: http://forums.turbobricks.com/showthread.php?t=250257

[TestPoint]

. . . this time about the size of the fuel pressure line tubing. The Volvo hard line is 5/16" and the regulator in is 3/8". Since the Volvo tube has no barbs and the regulator does I decided to stretch the 5/16" over the larger barb rather than try to crimp the 3/8" tight on the smaller tube. Just another of the thousand decisions that have to be made.

Second Effort! CAUTION: The pressure side of this system deserves special attention to connections. The Volvo Diesel hard line into the engine bay does not have a barbed or even a flared end. Mine blew off with a single solid fuel line clamp. I used a flare tool to add a very slight flair and the clamp added some semblance of a barbed connection and secured with a couple clamps. The gas Volvo fuel lines had flares and flare nuts. At that running pressure it will dump a lot of fuel quickly.



Off to the garage to install.

The parent document for this thread can be found here: http://forums.turbobricks.com/showthread.php?t=250257

[TestPoint]

After struggling with electrical connection issues associated with the custom tune upload for a month I gave up and moved on to another restoration project.

Now, almost a year later, after overcoming the PATS refusal to operate the injectors perhaps I have got that solved. For those not familiar with PATS, it is a Passive Anti Theft System that prevents such things from happening and also effectively prevents engine swaps. For this series of Explorers you either you have to use the '96 - '97 PCM/harness/injector system, which doesn't use PATS, or a custom tune on the '98 - '01 Explorers. The injectors and the injector connectors are different within this series of trucks so moving the earlier system onto a later engine is no little issue that is further complicated by the differences in transmission harnesses.

PATS in this Explorer series prevents the PCM from operating the injectors and I have heard from others that it does other things like not operating the fuel pump and/or disabling the spark in other years. In START and RUN there is permanent B+ on the red lead to each of the injectors. The PCM provides a ground controlled by input from the Cam Position Sensor (CPS). Only after getting the custom tune correctly installed did I see the grounds from the PCM on the two injectors that I could access around the intake manifold.

Loading the tune is a whole 'nuther' story discussed in the Custom Tune chapter.

The engine, at this point, would run for a moment on starter fluid but not on gas. Because I was seeing injector electrical operation efforts I tried a direct ground on the PCM side of the injectors with the ignition on. I could not detect, by sound or feel, any operation of the injectors. With that, off came the whole top of the engine and the injectors were sent to the injector spa.



New injectors were found for about $22 on eBay, re-manufactured ones from $12 to $35 and off-the-car cleaning service ranged from $8 to $30. Of course, I chose the $8 version from Fuel Injector Physician of Orlando. Seth was a great guy to work with. While they do a large business through eBay they would prefer to sell directly. Contact them at: fuelinjectorphysician@gmail.com They reported that the injectors were so gummed up that it took three soak sessions before they could move to spray cleaning but finally ended up balanced within +- 1%. I had mine cleaned rather than buy a refurbished set because they only had 11k miles on them. For only a few dollars more they will send you a full set of cleaned, tested and matched injectors.



The parent document for this thread can be found here: http://forums.turbobricks.com/showthread.php?t=250257

[M.H. Yount]

Reckon it sat for a while with gasoline in them Tom. Just borrowed a neighbor's brand new power washer. 3 years old and only started once when new to be sure it ran. He drained the tank, but the carb/float bowl still had gasoline in it. Wouldn't start, and I had to take the carb/float bowl off and clean out all the tiny orifices -- using a single strand of copper liberated from a piece of 12 gauge wire. Paper clip was too big. Of course, once the varnish/tars were removed (it was all black in color) - she fired right up and ran just like it was 'sposed to. I reckon yours was a more complex x8 version of that.