The external fuel pump, on my 89 is making a squealing noise that sounds like something is rubbing inside, and my car died. Let it sit and it'll start but starts to lope.

I figure the pump is history, or close to it. Mine also has the internal pump.

So, do I change the external green one, and a new filter, or while I'm at it, pull the internal pump for an inspection, and get the kit to replace the hose that is famous for deteriorating, and jamming everything up? Or go to the screen in the tank, with a pump that doesn't need the internal pump?

My car is supercharged, with 36lb injectors, if that makes a difference.

I want to do this right the first time, and not have to screw around with this again.

I'm open to all suggestions and advice.

Thanks in advance!
joe

 

I'm running the same SC set up as you Joe and have the strainer, '87/'88 fuel pump and it's all factory. Some say you will run out of fuel at the top end but I've never found that to be a problem.

 

Joe, You're there, you're gonna be that close to everything, might as well take the time to pull the internal pump and make sure everything is good before you button it all back up.

 

That's kinda what I figured. Is there any precautions I should take as far as unscrewing the internal pump? I don't want to pull the threaded insert outta the tank. That's a problem I damn sure don't want!

FWIW, I sprayed the hell outta the CPS sensor with PB Blaster, a month before I swapped in the new one. I pulled the old one out with my fingers, just a little wiggling.

 

Use a lot of PB Blaster ahead of time. A great idea by Jim Corenman, I think, who thought of putting a large hose clamp around the plastic that holds the threaded insert before attempting to unscrew the internal pump.

 

Thanks Sean and John, great ideas!

 

Joe --

I probably don't need to remind you that low fuel pressure and the resultant lean condition under load will fairly quickly demolish your engine. And that the two-pump setup was installed for exactly your non-winter climate there in LV. IMO, having both pumps working correctly will be essential for your SC engine's survival there.

Things to buy in advance: The fuel pumps. The banjo washers. A filter. The S pipe. Greg's inner fuel line hose and clamps. The hose between the nozzle and the outer pump. The ring seal for the nozzle fitting at the tank.

Things to consider: The main pump may be howling because the inner pump is clogged or not running. FredR posted some pics of the inner pump workings in a recent thread, showing two small plastic spider impellers. Even a small bit of debris can stop them or block flow. There's an inlet strainer on the inner pump that -should- keep debris out. You can try reversing the polarity of the current flowing to that inner pump, but even under the best circumstances that might spit the crud back into the inlet filter rather than into the tank, so it will be back into the pump pretty quickly. Other possible failure modes include that connecting hose deteriorating and flaking into the big pump, although that usually stops the pump rather than causing it to be noisy. Regardless, you'll want to take the whole assembly out of the tank for inspection if not replacement.


-- Drain the tank before you start.

-- Disassemble the covers from the pump area. Plan to support the tank so you can pull the tank support straps for access to the nozzle fitting.

-- That nozzle fitting has a rubber-ish (probably neoprene) seal that does the sealing between the fitting and the tank. You'll need to get that seal completely out if you want the PB Blaster or ATF/acetone to get to the threads. Some combination of Exacto knife and some dental picks will help with this.

-- Jim Corenman's suggestion on the hose clamp is excellent. You'll want a narrow clamp because of a reinforcing rib at the nozzle. I think I was hunting for a 6205 Ideal clamp for this, and ended up using multiple 6203's screwed together. 6203 is a large pre-FI style fuel hose clamp.

-- The hose that connects the nozzle to the outer pump is interesting, in that it is NOT a plastic-lined fuel hose hose as almost all the rest of the system is. This hose, and the return hose between the FPR and the fuel cooler, are the only hoses in the system that will tolerate a clamp to pinch off flow, at least per the WSM and supplements. The reason I mention this is that it may be tempting to use normal FI hose for that piece, and that would limit your ability to swap fuel filters or pumps in the future without draining the tank.

-- You can open the top of the tank where the fuel level sender sits to eyeball the inner pump and strainer. Obviously the tank is going to be full of explosive vapor, so use appropriate caution through the whole exercise. Charged garden hose, fire extinguisher, and I recommend that you do the venting outside where there are no sparks and less chance of fire taking the garage and house. Good Thing It Isn't Hot Outside! Once the top of the tank is open, you --may-- be able to get some PB Blaster into the the threads of the nozzle fitting. Or put a pint or so of the ATF/acetone blend into the bottom of the tank and let it go to work on those threads for a day or two while you do other things.

 

Thanks Dr. Bob!

Just got off the phone with Roger, ordered every thing I'll need as far as new parts. I'll be keeping the internal pump, ordered the hose kit, got to pull it, might as well do it right!

My car is outside on the lift, and I haven't really run it much. Changed the Hall and CPS sensors. Those two were worse than changing the tranny! Replaced all the relays in the CE panel, plus cleaned everything too, including grounds.

I have every thing a professional shop has, as far as a lift, 3 stage trans jack, cherry picker, air compressor, hand and power tools.

I need to get it running, then back in the garage. I have to return to the oil patch, for a month or so. Then it's new motor mounts, that Dee bought me for the 87. It was totaled before I got to install them and this one needs new mounts. Top end refresh, and should be ready for 3rd coast in November. If not, we'll have to drive the Polecat, that thing eats gas like it's still 23 cents a gallon.

 

Here's all the news that's fit to print!

First and foremost, A big thank you to Roger, 928'Rus!!!!!! He dropped every thing, and sent me all the new stuff I needed over night!

FWIW, when ya have to change out your fuel pump, plus the internal pump, the frigging gas tank will always be full!!!!!!!! SOB!!!!!!!!! On top of that crap, it's 110 degrees in Vegas. I know I'm a Hells Angel, but there are times, when living in the infernal regions gets a bit much.

I'm down to the short strokes, and I don't have a 36mm socket! WTF!!!!!!!!!!

Been nipping on the Turkey Bird 101, all day! Had to send the ole lady to get me a socket. My girl returns, with a 36mm socket 3/4 drive, a 1/2 to 3/4 drive adapter, and a jug of barrel 160 proof Turkey.

I hope I don't spin the tank insert removing the internal pump.

 

That's some funny ****. Hang in there you old fart. You got this covered.. lol

 

When we get down to Phoenix, I'm gonna drag you and Andrew outta that shop, and we're gonna tear it up!

Now I know Andrew can hang, but ya better start getting healthy! Ya ain't no spring chicken any more Kevin!!! LOL!

 

Clamp it! Like this, from this thread: https://rennlist.com/forums/928-foru...l#post11611596

A little metal reinforcement will make the summbeech a lot harder to spin.

 

We are in Joe ! Just let me know when. Would be great to see you.

 

Jim, do you happen to remember the clamp part number & brand? We looked at all the local places and came up empty. I have this service on my radar, and would rather use one correct clamp than try to get three strung together.

And Joe, what's the 36mm socket for? I've only pulled one nozzle fitting, the one on Jim Chambers' '78 car. IIRC it took a 16mm (very odd size for a German car...) for the fitting. I have a 36mm socket for the early air-cooled cars (axles and flywheel) so no worries, just curious.

And yes, Edsel Murphy reminds us that even if the tank isn't full when we experience a pump problem, our first instinct is to fill the tank and see if that helps with the starvation symptoms.

Also: Don't get the Turkey and the drained fuel confused as you work. The car won't run on the Turkey.

 

Turkey bird 101.............too funneee Joe

The fuel pump can be a light switch when it goes; ask me how I know. Doing all thats described is a solid plan as up here in the frozen North we dont quite get to temps needing the internal pump.

Dr. Bob.........16mm is now quite common and used much on the Cayenne; had to go to store and add some tools especially for the upper engine mount.

Good luck Joe, the peace of mind having the fuel delivery new and safe is well worth it.