RobzWorkz #8a: Improving the 328 Fuel System and Peripheral Hoses (Disassembly)

Hello again FChatters!!!

It is now time for me to publish my work on the refurbishment of the 328 fuel system. For this effort, I am including the following: the fuel tank, pump and piping; the evaporative emissions system; the air injection system; the blow-by system; the auxiliary air system; the CIS, and; the brake vacuum line. I have lumped all these together because 1) they have hoses that need replacement, and 2) they deal with engine fuel and emissions management. Although the exhaust system is related, it doesn't have hoses and can be deferreed as it's own project; I am still thinking about whether or not to keep the cat, and, my lambda circuit was functional at the start of this effort and does not need to be altered.

As of this post, I have completed all systems save the CIS and cold fuel/air mixing (the air lines under the intake plenum). At the end of this thread, I will post pictures of diagrams showing hose sizes and lengths for the systems completed. The CIS measements haven't been made yet and will be deferred until its thread is published. I'm still deciding on CIS materials (sorry Verrell, I'm concerned about polyamide and compatability with ethanol blend fuels; if you have data, please share).

Hoses were acquired from SRI (Dave Helms) and Aeroquip. Dave's fuel tank hoses are well-established in the FChat community. Aeroquip hoses having the AQP elastomer have excellent fuel and oil operating performance at engine temperatures, including ethanol blens. I will disclose the hose identifications in the drawings.


---------------------------------------SAFETY FIRST---------------------------------------

1) the fuel system is flammable and can be explosive;

2) remove all sources of flame and spark in the work area prior to releasing fuel (this includes another engine--car, lawnmower, etc);

3) disconnect the car's battery until all fumed are removed (this is a spark/heat generator);

4) if draining the fuel system, store gasoline in a proper container (gas can or another car);

5) store all gas away from the project area or in appreoved containers sealed from the atmosphere;

6) all fuel-related elastomers will dry and crack when dry; it is essential to replace all elasomers (hoses, o-rings, seals, etc); not doing so can create a deformed or cracked system which could catch fire or explode;

7) after draining, eliminate all fuel vapor build-up in all systems (including the tanks) with fresh air flow until no smell of gas is sensed (to properly sense vapors, exit the project area and breathe normal air for several minutes so as to prevent getting used to the vapors; then return and smell for fumes); fresh air sources can have motors creating sparks; take precautions to keep these from fumes;

8) as expected, conduct your own efforts at your own risk; common sense and preparation will be your best security.



Now to begin:

A. PREPARATION.

1. Drive the car to reduce fuel amount in the tanks. It is not necessary to run out of gas; olny be sure to have a low enough amount sa as to store elsewhere.

2. Park the car in the project area and allow to cool.

3. Loosen, but do not remove wheel lug nuts.

4. Using commonly-understood procedures, place the car on jack stands or a lift. Be sure to keep supports away from areas to be removed during the project. Be sure to lift the entire car. Never work under a car which is not fully supported (do not use only rear jack stands).

5. Remove the wheels. I place my wheels under the car to provide additional safety margin. I also use a wheel to stand on to gain better access.

6. Disconnect the car's battery.

7. Remove all sources of flame and spark.

8. Gather tools and gas storage container.

9. Remove rear wheel well liners (I removed all four so I could clean/inspect all over).

10. Remove air ducts and air cleaner assembly.


B. DRAIN FUEL FROM SYSTEM

1. Be sure all spark/fire sources are off or far away.

2. Obtain a drain pan suitable for holding gas into which to drain.

3. Place pan under left rear fuel line goint to the fuel pump.

4. Open left access grill to gas cap. DO NOT OPEN GAS CAP YET.

5. Loosen and pull off the fuel hose (tank to pump) at the tank nipple. Fuel will start to drain into the pan at a modest flow. Allow fuel to drain into pan. If pan fills too full, replace hose and tighten, pour gas from pan into awaiting storage container, and return to draining the tanks. (NOTE: if it is necessary to cut the hose to allow draining, be sure to have a pan large enough to capture all the gas; if not available, drain from the crossover while using the drain plug to interrupt as needed).

6. To increase gas flow, crack open the gas cap.

7. When flow stops, place gas in pan into storage vessel. Be careful to minimize fuel spillage.

8. Remove gas cap.

9. Place pan under crossover drain plug and open the drain plug. Very little gas should be remaining at this point.

10. Place/Ensure all gas is stored in container. The system is now ready to disassemble.



The pics below show the process up to this point.
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Leave the system open to vent and allow fumes to dissipate through the gas cap. Take a break as this happens (overnight is excellent). Be sure to not close up the work area but allow to vent to outside.

Now is time to remove all the gas tank flexible hoses. These include: the hose from tank to pump; the two crossover hoses, and; the filler neck hoses.

Removing hoses ranges from easy (loosen clamp and pull off) to annoyingly hard. Take your time. Use the right screwdriver/wrench. Sometimes cutting will free hose better than wrestling...use a utility knife and avoid scoring metal.

To remove the crossover lines, remove the battery cable disconnect cover and the crossover pipe retainer; this will allow better manipulation of the crossover flex lines for removal.

To fully remove the crossover pipe will require removing the right side heat shield assemble. It will likely be very dirty anyway, so clean it too.

Remove the filler neck as well. Do this after removing the hose. Removing the neck is done by removing the bolts from its bracket and removing the attached vent hose. Be sure the gap cap is removed and then pull out from the bottom. Now remove the big filler neck gasket from the body (at the gas cap).

Remove the overflow line as well.

Pics below show my effort:
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Yeeeesssss!!!!

You are all correct...old worthless hoses!!!

Evil! Evil! Evil!

 

Basically, cut and remove hoses and components for the evaporative emissions system and the accumulator relief.

To remove the top vent braided hose, cut the plastic clamps.

To remove the crossover vapor pipe requires a deep well socket (I recall 10mm). I discarded these and replaced with an aluminum channel bracket on which I attached the new and reconditioned stuff(see later). This will also dismount the fuel pressure line from the filter.

Remove the vapor separator, the check valve and rollover valve as you go.

Also remove the vapor cannister.

Also, disconnect the brake vacuum line.

It's all nuts, bolts and clamps.

Pics below.

The last pic shows how I used a piece of hose to retain the upper heat shield flap in place while removing the stubborn nuts. These nuts retain the hose mounts and the upper heat shield altogether.
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No knowledge here, Steve. That's why I'm a replacin' it all!

 

Caution: there will be fuel in the downstream lines after the fuel pump. Be prepared and remember the safety precautions from above. NO CIGARETTES!!!

To release fuel pressure, crack open the fuel hose from the fuel accumulator outlet (Note: I found that trying to remove at the filter was a no-go here).

Wipe up fuel drops with a rag and let it dry out in the outside air. This only released fuel pressure up to the distributor. There is still some residual there and in the injector lines.

Disconnect the electrical connections from the fuel pump: one hot with protection and one ground on a mount.

Remove the fuel pump and accumulator as an assembly; this is done by removing the mount attachments. There are three of these mounts. For my 328, two were removed by removing the lower nuts; the third nut was tack welded to the frame and thus the mount had to be rotated out.

Disconnect the fuel supply line from the metal pressure line and remove the fuel filter and pressure line as an assembly. Wipe up fuel here as needed. To remove the filter, loosen the large circlamp.

Disconnect the fuel return line and remove the return pipe with its hose from the top of the right tank.
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To remove the aux air system (up to the intake plenum), loosen the hoses, disconnect the electrical connector from the aux air valve, and remove the aux air valve from under the coolant tank, all as a unit (see pic).

Remove the Air injection hoses as a unit (see pic without long hose attached). Disconnect the vacuum line from top the vacuum valve (it's attached to the electrovalve under the coolant tank).

Remove the blow-by upper hose network (my 3-way pipe was mangled so I bought another; be careful if you will be keeping yours...it's cheap aluminum). Disconnect the lower blow-by hose from the front of the engine and remove the oil separator with its lower hose. Remove the blow-by hose from the left side of the rear head; it's gasketed to the head, so be sure to be careful and remove gasket slivers.
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I agree with you, Dan, but it's such a hassle reinstalling. I used one of my wheels as a step stool to get better access.

 

Since I'm doing a full disassembly, I chose to remove theair flow sensor and CIS fuel distributor as a unit. The sensor body is mounted to the rear wall and to the frame with 3 cushion mounts (like for the fuel pump assembly).

First, disconnect the fuel safety connector and the frequency valve connector.

Remove the large riser tube.

Disconnect all the CIS injector lines from top of the distributor. Fuel drops will likely be present. I retained the copper washers with their associated bolts. Move the lines out of the way.

Disconnect the lines to the WUR (warm up regulator) and CSI (cold start injector). Fuel drops again. I retained the copper washers with their associated bolts. Move the lines out of the way.

While supporting the air flow sensor body, undo the three mount nuts. Remove the body.

Pics below.
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Now to remove the remaining CIS components: the WUR, the CSI and the injector lines (the injectors remain in the intake risers).

Remove the WUR and CSI first. Both have electrical connections to remove first.

Then disconnect and remove the TPS (throttle position switch). This will make room to remove the rear CIS injector lines.

Remove the rear CIS injector lines. Fuel drops will be present.

To remove the front CIS injector lines, undo the elbow from the CSI mount and rotate it out of the way; then unscrew the mount from the intake housing. Then remove the CIS injector lines. Fuel drops will be present.

Pics below.
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I agree with you David, which is why I took extreme care.

Most of the nipples on top of the tanks were straight pipes and the hoses were easily removed. Only 4 had lips that were obstructive to hose removal: the filler neck, the rear vent lines and the fuel return line. The filler neck and vent lines were easy to remove from under the car (from within the fender wells). The fuel return line nipple was corroded and (much too) easily broke off; my repair of this is forthcoming. Also, as you will see, I was extremely concerned about these tank top fittings: I reinforced all with QuickSteel to reduce effects of memory stress. If I had removed the tanks, I would have TIG-welded new pipes altogether.

For me, having minimal places to store large (and heavy...you need a partner to reinstall) components, leaving the deck lid in place was the best solution. I had no trouble throughout all of this effort. Using a wheel as a step stool helped more than anything to gain access from above.

 

RFI (request for information): during this project, I will be replacing the throttle cable; thus, when removing the throttle body, I simply cut off the end of the cable. I will replace as I reinstall the intake later. My request from the FChat community would be to explain throttle cable removal and installation from under the intake plenum without removing the plenum (if possible). A thread reference with pics would (of course) be best.


Now, remove the throttle cable attachment at the body and remove the throttle body. Disconnect vacuum lines to WUR (I lest attached here) and the air injection electrovalve.

Pics attached.
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This was my first time removal of this intake, so I went slowly and carefully so I could best understand its removal. My inclination was that I could remove the plenum and risers as a unit. However, if the risers were mounted onto the block at an angle, this could prove untrue and I would have to remove the plenum first.

The risere are mounted at an angle, which will be seen soon enough.

However, good news: all three intake parts can be removed together if the plenum is loosened and not removed (no losing spacers into the block). Then, there is enough play to remove all three components together.

This will work if the throttle cable is cut. If the cable is to be kept uncut, remove the plenum first (see note below).

THE PROCESS:

First, remove all the nuts and washers retaining the risers on the block. Keep a magnetic retriever handy to assist and pick up straggling pieces.

Then, using a razor blade at the rear riser to block mating surface, start cutting into the gasket area and (softly) tap into the gasket with a hammer; then use a larger implement to spread (I used a putty knife); then work the surface periodically with a small screwdriver while avoiding the mating surface (don't let the screwdriver go in towards the surface by more than 1/8"...don't wand to dimple the surface).

Once the gap is started, manipulate the assembly as a whole wo work apart. For me, the entire rear riser surface was loosened by alternately prying from the right and the left.

Once the rear is loosened, work the front loose by manipulating (generally rocking) the whole riser/plenum assembly and with prying right and left on the front risers as was done with the rear riser bank.

After assured that both front and rear riser mating surfaces are freed, loosen all retaining fasteners for the plenum...do not remove, just loosen. As the plenum is loosened, more play will be observed at the riser/block surfaces. When enough play is realized, remove the entire plenum/riser assembly as a unit.

It's fairly easy if patience is exerted more than frustration.

Lastly, I removed the throttle cable retainer (recall, I cut my cable so there was no weirdness from having the cable still bolted into the intake when removing; if you were not going to cut off the cable, then remove the plenum first and be careful with the plenum to riser spacers; use a magnet to prevent losing them into the cylinders).

See pics below. The last three pics show the following: 1) that the assembly is mounted to the bloock at an angle; 2) the amount of plenum-to-riser gap which allowed enough play to remove the as a unit, and: 3) the top without the intake.

If you review my RobzWorkz #7 about refurbishing the coolant system, you will see the portion where I improved the cooling area under the plenum therein.
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FYI, It's a good idea to plan out retrieving your materials as part of the effort. However, until now, there was only dispersed information about hose lengths and sizes.

So, here you go: all the hoses to be replaced, save for the CIS lines (deferred until I do them), are presented in the following edited diagrams. They are system-based and use the common diagrams for the 328.

Each hose identified includes a callout with the "minimum length" in inches, the approximate inch fraction inner diameter, the caliper-measured decimal-inch inner diameter at the nipple body (not the lip, which is greater) and the approximate mm-equivalent. Of course, the caliper-measured lengths are the most precise.

The "minimum length" is the minimum I recommend purchasing so as to be able to cut to the length necessary for installation with slack. This is essential since every person will install slightly different and slack allows for that.

BTW, if you do not want to cut hose, don't do this project. All hose was easily cut with a utility knife for hoses not metal braid, and with a Dremel cutoff wheel for hoses with metal braid. Clean hoses inside and out after cutting with a wheel (compressed air works).

Also identified are the hoses I used for my work. These are not the only available in the market. My choices were SRI for the fuel tank hoses and Aeroquip for the remainder. There is a callout in the lower right identifying my hose selections.

SRI hoses do not include inch measurements since they came in a ready-kit.

My hose choices for the emissions and vent systems will seem to be overkill. These were metal braided hoses with blue cloth overbraid. After realizing the hoses were very stout, I looked for alternatives and found the variability at Aeroquip was limited with respect to hose flexibility (bend radius) and kept my original choice. To facilitate the bend stress of these hoses (try not to stress fittings with hoses), I integrated bent steel tubing for curved paths. Thus more-flexible hose would be desireable in this case.

All Aeroquip hoses selected used the "AQP elastomer" as the inner tube. My review of materials compatibility showed that this was excellent for my applications and temperature ranges.

For some fittings with lips (larger diameter at tip), for some of my hoses, especially metal braided types, installation was a no-go for nipples with lips D)). So, I chose different hose sizing and construct. These changes are reflected in my hose identifications presented. Thus be aware that you may need to repurchase hose with more flex to accommodate lips on tube ends.

Many of the clamps were reusable after cleaning...many needed replacing. I used new clamps for adding bent tubing as well.

For the ramainder of this effort (hose installation, etc), I will post in new threads (#8b, c,etc).



I strongly recommend FChat feedback with regard to methods, measurement errors and hose choice alternatives. That is one reason I consider my posts here as "peer-reviewed" material.
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Hey, that's what the pics are for (I use FChat as my backup storage drive).

BTW, thanks Greg.