Fuel Pump - Cavitation
BULLETIN NUMBER ISSUE DATE GROUPSB86-02-008 November 7, 1986 FUEL
IMPULSE (JR) FUEL PUMP CAVITATION (VAPOR LOCK)
VEHICLES AFFECTED
1983 - 1986 Impulse (JR) non-turbocharged models before:
VIN Production
Date
AIMI vehicles G0903442 11/11/85
Non-AIMI vehicles G4044298 12/6/85
SERVICE INFORMATION
A combination of excessive fuel volatility and high ambient temperatures may result in fuel vaporizing in the fuel pump suction line, causing pump cavitation. A field fix kit is available to counteract these conditions, where present; it adds a secondary fuel pump (sub-pump) and vapor separator to the fuel system.
SERVICE PROCEDURE
WARNING Even after the fuel tank is drained, fuel remains in the pump and lines. Use extreme caution throughout this procedure and have an approved fire extinguisher available.
1. Disconnect the battery negative cable.
2. Remove the drain plug from the fuel tank and drain the fuel into an appropriate container. Removing the fuel filler cap will allow the fuel to drain faster. Reinstall the drain plug and filler cap when the fuel has finished draining.
FIGURE 1 - METAL FUEL RETURN PIPE:
3. Working within the engine compartment, separate the metal fuel return pipe from the hose leading to the pressure regulator (Figure 1). Unbolt the bracket holding this pipe (about 4 inches from the open end of the pipe).
FIGURE 2 - BLACK PLASTIC SHIELD:
4. Remove the black plastic shield from below the right-hand rocker panel (Figure 2). This exposes 3 metal fuel pipes and 1 metal brake pipe.
FIGURE 3 - FUEL PIPE BRACKETS AND CLIPS:
5. Remove all visible fuel pipe brackets and clips. Brackets are bolted to the body (Figure 3) and may be all metal or a metal/rubber combination. Clips are held in place by the pipes themselves. Some brackets may not be visible until other components are removed
in later steps. Save all brackets and clips for reinstallation.
6. Remove 3 bolts holding the fuel filter bracket and remove the filter from the bracket.
7. Near the fuel filter, remove the bracket which holds the fuel return pipe, the engine ground cable and the speedometer cable.
WARNING A large amount of fuel remains in the fuel pump. Have a container ready in Step 8 to catch this fuel.
FIGURE 4 - MAIN FUEL FEED PIPE:
FIGURE 5 - MAIN FUEL FEED PIPE:
8. Remove the main fuel feed pipe from the front of the fuel pump (Figure 4) and the rear of the fuel filter (Figure 5). Remove this pipe from the vehicle and discard it.
FIGURE 6 - FUEL RETURN PIPE:
9. Remove the rear end of the fuel return pipe from the hose which connects it to the vehicle fuel tank (Figure 6).
10. The fuel return pipe can now be removed from the vehicle. Pull the rear end of the pipe to the right to clear the rear sway bar, then lower it from the chassis.
Remove the bracket from the front end of the pipe and place it on the new fuel return pipe (part No. 8-94146- 669-3). Discard the old return pipe.
FIGURE 7 - FUEL PIPE:
11. Remove the fuel pipe between the vehicle fuel tank and the rear of the fuel pump (Figure 7); discard this pipe.
FIGURE 6 - FUEL RETURN PIPE:
12. Install the 3 new metal fuel pipes onto the vehicle; loosely install a few brackets to hold the pipes in place:
a. Part No. 8-94146-669-3 is the new fuel return line; it runs from the pressure regulator in the engine compartment (Figure 1) to the fuel tank (Figure 6). Use the original hose clamps to secure the hoses at either end of this pipe.
FIGURE 5 - MAIN FUEL FEED PIPE:
b. Part No. 8-94165-919-3 connects the front of the main fuel pump to the fuel filter. Use the original hose clamp at the fuel filter end (Figure 5); leave the fuel pump end disconnected for now.
FIGURE 7 - FUEL PIPE:
c. Part No. 8-94165-920-1 connects the vehicle fuel tank to the new vapor separator. Use the original hose clamp at the fuel tank end (Figure 7); leave the vapor separator end disconnected for now.
FIGURE 8 - FUEL PUMP BRACKET:
13. Remove the 4 bolts holding the fuel pump bracket to the vehicle (A, Figure 8). Remove the 2 bolts securing the pump to the bracket (B, Figure 8). Temporarily wire the pump to the chassis so it doesn't hang by its electrical harness.
14. Remove the rubber fuel hoses from the pump:
a. Replace the front hose with part No. 8-94403- 801-0; use 2 new hose clamps (part No. 8-94123- 526-0). Connect the front hose to the new fuel pipe installed in Step 12b.
b. Replace the rear hose with part No. 8-94166-804-
1. This rear hose requires 2 different hose clamps. Secure the hose to the fuel pump with clamp part No. 8-94122-679-0. Place a clamp part No. 8-94238- 568-0 on the rear end of the hose, but leave it disconnected for now.
FIGURE 9 - FUEL PUMP BRACKET:
15. Remove the rubber mounting grommets from the fuel pump bracket and transfer them to the new main fuel pump bracket (part No. 8-94430-366-0). See Figure 9.
16. Bolt the vapor separator pipe (part No.8-94167- 497-0) to the main fuel pump bracket using 2 bolts part No. 9-01900-612-0 (Figure 9).
FIGURE 10 - SUB FUEL PUMP:
17. Bolt the new sub fuel pump (part No. 8-94167- 493-3) to its bracket (part No. 8-94430-317-0) using
2 bolts part No. 9-01900-625-0 and plain washers part No. 8-94233-657-0. If the sub fuel pump has a connector and grommet on the end of its wiring harness (Figure 10), cut the wires and remove the grommet.
18. Install a new mounting grommet (part No. 8- 94205-837-1) and collar (part No. 8-94211-862-1) into the sub fuel pump's bracket (Figure 10).
FIGURE 11 - REAR SUSPENSION LOWER LINK SUPPORT BRACKET:
19. Drill a 7 mm hole in the rear suspension lower link support bracket; see Figure 11 for hole placement. Apply primer paint to the new hole.
20. Unwire the main fuel pump from the chassis and bolt it to its new bracket. Install the original bolts in the left front and right rear bracket mounting grommets and loosely bolt the bracket to the chassis.
FIGURE 12 - SUB FUEL PUMP BRACKET AND PUMP:
21. Install the sub fuel pump bracket and pump (Figure 12):
a. The bracket hole which has a rubber mounting grommet aligns with the right front hole in the main fuel pump bracket. Use the new long bolt (part No. 9- 01900-635-0) and plain washer part No. 9-09164- 806-0 to attach the two brackets to the vehicle.
b. Use a bolt part No. 9-01900-612-0 to attach the sub fuel pump bracket to the side of the main fuel pump bracket.
c. Use a bolt part No. 9-01900-612-0, plain washer part No. 9-09160-606-0 and nut part No. 9-09110- 506-0 to attach the sub fuel pump bracket to the rear suspension lower link support bracket (hole drilled in Step 19).
d. Remove the caps from the sub fuel pump pipe fittings.
FIGURE 13 - VAPOR SEPARATOR:
22. Install the new vapor separator (Figure 13):
a. The long, angled end aligns with an existing fuel pipe bracket and shares the bracket's original mounting bolt.
b. The forward end aligns with the main fuel pump bracket's left rear mounting hole and shares the original mounting bolt.
FIGURE 14 - INSTALLING VAPOR-SEPARATOR HOSES:
23. Install the remaining 4 short fuel hoses with their new clamps. The letters in Figure 14 match the following lettered steps:
a. Hose part No. 8-94411-934-0 and clamps part No. 8-94238-572-0 connect the upper right-hand fitting on the vapor separator to the rear end of the short pipe (bolted to the main fuel pump bracket).
b. Hose part No. 8-94411-864-0 and clamps part No. 8-94238-568-0 connect the fuel pipe (from the fuel tank) to the left-hand fitting on the vapor separator.
c. Connect the previously installed hose from the rear of the main fuel pump to the lower right-hand fitting on the vapor separator.
d. Hose part No. 8-94411-979-0 and clamps part No. 8-94238-572-0 connect the front end of the short pipe (bolted to the main fuel pump bracket) to the lefthand fitting on the sub fuel pump.
e. Hose part No. 8-94411-980-1 and clamps part No. 8-94238-572-0 connect the right-hand fitting on the sub fuel pump to the tee fitting in the fuel return pipe.
FIGURE 15 - ARRANGING HOSES:
24. With all hoses, clamps and pipes installed, arrange the fuel pipes so that they fit within their brackets and do not rub against any other parts of the vehicle. Figure 15 shows two critical routing areas:
a. Install the protective tubing part No. 8-94131- 769-0 on the rear brake line in area A, Figure 15, to protect it from the coupling in the new fuel return pipe. Split the tubing lengthwise, coat the inside with quickdrying adhesive and wrap it around the brake line. Trim the tubing ends as needed if they extend beyond the area of possible contact.
b. Install the protective tubing part No. 8-94164- 011-0 on the evaporative emissions pipe in area A, Figure 15, to protect it from the return pipe coupling. Install and trim the tubing as described in Step a above.
c. In area B, Figure 15, arrange the fuel pipes so that there is clearance between all pipes.
25. Tighten all fuel line brackets and install all clips removed during disassembly. Install the fuel filter into its bracket and bolt the bracket to the vehicle.
26. Install the black plastic shield (Figure 2).
27. Remove the rear seat bottom cushion by pulling the front edge of the cushion up and forward.
FIGURE 16 - SUB PUMP WIRING:
28. Insert the two bare wires of the sub pump wiring harness through the floorpan grommet (Figure 16). To prevent water entry, seal the grommet area with RTV sealant.
FIGURE 17 - WIRES OF THE SUB PUMP HARNESS:
29. Pull the bare wires of the sub pump harness as far as possible into the car. Strip the insulation as required to install the spade terminals provided with the kit (part of connector part No. 8-94124-739-0). See Figure 17.
FIGURE 18 - SPADE TERMINALS:
30. Install the spade terminals into connector part No. 8-94124-739-0. Note the polarity shown in Figure 18.
FIGURE 19 - FUEL PUMP CONNECTOR:
31. Locate the original fuel pump wiring connector and separate the connector halves. The connector
may be visible once the rear seat cushion has been removed or it may be tucked behind the right-hand trim panel (Figure 19).
FIGURE 20 - WIRING HARNESS ASSEMBLY:
32. Install the new wiring harness assembly (Figure 20). The new harness has 2 connectors at one end; these plug into the original fuel pump connector halves. The single connector at the other end of the new harness plugs into the connector installed in Step 29.
33. Tape the new harness assembly to the floorpan. Tuck the main fuel pump connectors behind the righthand trim panel, if the original connector was located there.
34. Install the rear seat bottom cushion. Make sure the seat belts are properly placed.
35. Refill the vehicle fuel tank.
36. Connect the battery ground cable.
37. Start the engine and check carefully for fuel leaks.
38. Reset the digital clock.
FLAT RATE MANUAL UPDATE INFORMATION
OPER.
OPERATION TASK SPEC. I-MARK I-MARK IMPULSE
NUMBER INSTR. (PF) (JT) (JR)
020399 SUB-FUEL PUMP Install - - 2.5
FIELD FIX KIT
Trouble code 71
PARTS INFORMATION
Part No. Description
2-90029-710-0 Field Fix Kit
This kit contains the following parts:
Part No. Description Qty.
8-94167-493-3 Sub fuel pump 1
8-94428-405-0 Cable asm. (wiring harness) 1
8-94430-317-0 Sub fuel pump bracket 1
9-01900-625-0 Bolt 2
8-94233-657-0 Plain washer 2
8-94427-404-0 Vapor separator 1
8-94430-366-0 Main fuel pump bracket 1
8-94124-739-0 Connector (wiring) 1
8-94205-837-1 Mounting rubber 1
8-94211-862-1 Collar 1
9-09164-806-0 Plain washer 1
9-01900-635-0 Bolt 1
9-09160-606-0 Plain washer 1
9-01900-612-0 Bolt 4
9-09110-506-0 Nut 1
8-94167-497-0 Pipe (separator to pump) 1
8-94411-979-0 Hose (pipe to sub pump) 1
8-94411-980-1 Hose (sub pump to return pipe) 1
8-94411-934-0 Hose (vapor separator to pipe) 1
8-94238-572-0 Hose clamp 6
8-94165-920-1 Pipe (tank to vapor separator) 1
8-94146-669-3 Pipe (return) 1
8-94411-864-0 Hose (pipe to separator) 1
8-94238-568-0 Hose clamp 2
8-94166-804-1 Hose (separator to main pump) 1
8-94122-679-0 Hose clamp 1
8-94238-568-0 Hose clamp 1
8-94165-919-3 Pipe (main pump to filter) 1
8-94403-801-0 Hose (main pump to pipe) 1
8-94123-526-0 Hose clamp 2
8-94131-769-0 Tube (brake pipe) 1
8-94164-011-0 Tube (evaporative pipe) 1