Appears right bank is not firing. Motor stumbles badly between 500-1500rpm and will not hold an idle (ie, dies). Exhaust from the Right bank is cold with no outward pressure. Checked easy items: replaced fuel filters, cleaned all contacts to fuel pump/frame. Will check power to fuel pump next. If fuel pump not getting power seems like problem possibly id'd. Will then check fuses, etc. If fuel pump getting power, then the question is 'is the fuel pump bad'? What's the best/least mess way to check the fuel pump? Any other reasons the right bank might not be firing?
Right exhaust is left bank. Fuel supply is really the only possibility barring a cam belt problem. Pull the blue plug off the left fuel distributor and turn on the key. You should hear two pumps running.
Thanx for the response Newman. Should have explicitly said it was my left exhaust that was cold/no pressure hence no right bank. So, should I pull right fuel distributor blue plug instead of left? Also, what is purpose of pulling the blue plug? Do the pumps only run one at a time unless plug is pulled? Probably have this question all messed up! Thanx again.
It's the fuel pump activation switch which controls both pumps. The right distributor has no wiring going to the unused switch. When the sensor plate moves during cranking it activates the pumps, unplugging it does the same thing as moving the plate.
The purpose of the blue safety switch plug is to run both fuel pumps only during starter motor cranking (Pos III) or when in Pos II (key "on") and the engine is actually running (and drawing in air as Newman indicated). If you get in a bad crash and the engine stops running (with severed fuel lines) but the key is still "on", the fuel pumps don't continue to run, and spray fuel all over the place, immolating your unconscious body. Another way to individually test each fuel pump and its wiring (without running the engine) is to remove the fuel pump relay for that fuel pump and then touch a jumper wire from the female metal 30 terminal in the relay socket to the female metal 87 terminal in the relay socket: Image Unavailable, Please Login The corresponding fuel pump should (audibly) run (even with the key "off").
No trouble, please let us know what you find. I would also add that if you have a fuel pump that isn't running, the #1 suspect would be the fuse holder as they've been reported many times to have "melted" (so the riveted electrical connections go bad). Still could be a bad fuel pump, but just wanted to mention that you shouldn't go buy a new fuel pump unless you've verified with a voltmeter that you've got +12V between the two terminals at the fuel pump and it isn't running.
Followed inputs. Left fuel pump runs fine, but right fuel pump was getting no power at terminals. Checked fuse holder in glove box, and pic 1 shows the left fuse in pic is burned up (assume this corresponds right bank). What size (amp) and type fuse goes in this fuse holder? What is best online name part number to look for? Could not find relay panel location in workshop manual to check fuel pump relays, so where exactly is the panel in an 83/84 bbi? Another indirectly related electrical question for pics 2 and 3? Looks like multiple different size fuses in both fuse holders. Do the 8 and 16 on each cover indicate the amp fuses to be used? Clearly, on the right bank, the 3rd fuse from right is missing, and the second fuse from the right at some point melted the holder. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Your 224/81 OM specifies 16A fuses for the fuel pumps. Behind the Passenger footrest panel -- see page 101 in your 224/81 OM: Image Unavailable, Please Login (But you've probably already found the problem.) Yes. Again, see pages 101-103 in your 224/81 OM for information. Not good that fuse #16 is completely missing as that is what runs your center radiator fan, but you obviously have had some modifications done (in stock form, there is only 1 wire connected to the tops of fuses #16, 17, and 18) so maybe they did something else to address that. Not uncommon to have "melting" problems there -- especially as it is a place where people often "steal" +12V power to run something else that they've added (but that puts even more current stress on the fuseblock so even more promotes melting there). PS When you replace those fuel pump fuses (I'd recommend that you do both), make sure that the female "seats" that mate with the pointed ends of the fuses are very clean where they make contact -- maybe use something abrasive to expose fresh, unoxidized material.
I wonder a little about the colors of the fuses. 3rd photo shows a 16 amp fuse in the middle ( so from left as also from the right the 5th fuse ) where there should be a 8 amp may be in the US you have other norm? in europe: 5 Amp yellow 8 Amp white with golden metal 15 Amp white with silver metal 16 Amp red 25 Amp white with silver thick metal 40 Amp blue black and green fuses I never have seen, but the green one looks minimum 30 amp, even more
Success...installed two new 16amp fuses into the two fuel pump seats, and success!!! Thanx to all. However, also installed 16amp fuses in third seat from right on right side, but center cooling fan still did not run. Am also going thru each fuse to ensure it is either 8amp or 16amp as specified. I've noticed different manufacturers of the fuses have different metal and widths of metal in the fuse.
Measure the voltage from metal piece holding the top of fuse #16 to a good ground = it should always be +12V (even key "off"). It probably won't be OK because things look well frazzled/cooked. In the stock arrangement, there is only a single large red wire bring +12V into the top of fuse #17, and then the rivets and a plate on the backside of the fuseblock connects this +12V to the tops of fuses #16 and #18. Since you have a large red wire at the top of fuse #16, an added small red wire at the top of fuse #17, and another large red wire at the top of fuse #18 = definite molestation. The bottom line is the tops of fuses #16, #17, and #18 should always be +12V (even key "off"). Are your left and right radiator fans working OK?
All good and everything works! Was only 1 wire into top of #17. The wire behind actually was the looping wire going to the top of #16. Noticed the end of #16 top wire was hard as a rock and not mailable in the last inch. So, cut it off and put on a new female connector. Cleaned up all the burn indications and sanded all the connections top and bottom. Cranked the car up. All 12 cylinders and all three fans ran as advertised. Even the cig lighters that indicate are connected to #17 worked on both sides. Thanx again to all.
