CDJQ

Hi, Brett here from Sunny Merritt Island Florida. I've been using this forum for quite a few years and found it to be a wonderful wealth of information to keep my Shark running - so Thank You all for your hard work to keep these classics alive!
Onto my questions: I have been dealing with a rough running issue for a couple of years which was put on the back burner until recently (it was a money thing).... and now it appears it has become a no start issue!
I have gone through the ground checks thoroughly and everything looks pretty solid in that department. I have checked the fuel pump relay and it seems to work fine. Now I am looking at the fuel pump as the possible problem (note, there is no clicking in the engine compartment - phew!). I just jumped the fuel pump relay and I hear a little click noise at the fuel pump but I am not confident that it is actually pumping. If I remove the cap off of the fuel rail should fuel come out of it when the pump is jumped? My other question is - does the 97 S4 have a second fuel pump in the tank?
I apologize if these questions have been tackled here numerous times.... I tried to find some solid answers but there is so much information that it is overwhelming.
Thanks in Advance,
Brett
1987 928 S4 (White with a black fin!)

17prospective buyer

If you jump it, yeah, fuel should come out. Yours may or may not have an in tank pump. I think only hot climates had it, to eliminate cavitation. I don't think a failed in tank would cause a no start though. Unless something happened, there shouldn't be that much gunk in the tank, the screen is before the in tank pump.

Mine is a Canadian S4 so it doesn't have an in tank pump, but i would think it is powered through the same connector as the level sender? So if it has it, the level sender would have a couple more pins/wires. Sounds like it's just dead. You could take it off and try reverse polarity on it and see if it'll work. You should hear it run for a couple seconds in normal KOEO (key on engine off) mode, and of course a constant hum if you jump it.

You asked about the fuel pump so i assume you've checked all the stupid stuff, fuses, wiring?

Guys reading: Aren't there a couple sensors that can cause a no start when bad? I'm sure there are a few stupid little things that will cause a no start. Sounds like seized up fuel pump to me though, if there's a click but no humming.

The Forgotten On

Replace your temp II sensor and check for vacuum leaks, those are classic issues that could cause a no start or poor running.

Replace your fuel pump if it is original and if you have an in tank pump, replace it with a tank screen

The line that is inside of the in tank pump can break down and send chunks of pipe into the external pump causing it to jam.

Those are a few things to do and check, also check resistance on your maf and if needed, have it rebuilt.

Good luck

jcorenman

It if just clicks when jumpered, instead of making "whirring" motor noises, then the pump is toast.

Yes, absolutely. Lots of fuel, be careful.

As Matt said, likely not. Remove the pump cover under the tank, follow the hose to the tank fitting, and check for two wires there-- that's where the second pump lives, in place of the inlet strainer/tank fitting.

There are other things that can cause a no-start, but you need fuel pressure first.

And Welcome !!

SeanR

^^ this guy just told you all you need to know.

outbackgeorgia

My USA 87 S4 5 speed does NOT have an in tank pump. I do carry a spare.
Dave

CDJQ

Thank you everyone for the great info. When I get home later today I will further look into the problem. I have checked the obvious (relays & fuses & wiring) and the Maf was rebuilt about a year ago (I had bought it from one of the bigs and it died before the warranty expired so they rebuilt it again for free). My gut instinct says the fuel pump is the reason for the no start so I will remove that first (I am almost certain it is the original pump). So once I get the fuel back to the motor then I can begin to look into the rough running...... I will post my results as they unfold.
Once again, thank you for all the help!
Brett

jpitman2

My pump did this once, after being turned off in very hot weather in traffic. Just went click with power. After getting it out (external, no in-tank fitted), I applied reverse polarity to it, it went HUH!, spit, whirrrrr. Refitted, ran for another 5+ years. Try this before removing, just in case. If you have an in-tank pump, there will be 2 wires connected to the side of the tank outlet screw in fitting. If not, the wires will be taped up out of the way. Mostly the in-tanks are more trouble than they are worth - remove, replace with the std strainer , with anti-seize, only tightened enough to stop leaking.
jp 83 Euro S AT 55k

Alan

Err - don't think so on this model year

Alan

17prospective buyer

You sure? I thought that function has been around for a while? ECU shuts pump off if it doesn't see an RPM signal above cranking RPM (<400) after a specific time (2 seconds usually) in KOEO. Maybe that was an OBD CAN thing.

928 at last

[QUOTE=CDJQ;11046237] does the 97 S4 have a second fuel pump in the tank?

Dunno...we'll have to try to find a '97 to check.....
Seriously though, my '90 had an in-tank unit that screwed up and jammed the external pump. If its not humming, it's not pumping.

outbackgeorgia

USA 87 does NOT have an in tank pump. See post 6

GregBBRD

And because of this, requires a different external pump than the vehicles that do have the internal pump.....extremely important!

jpitman2

After L-jet the pump relay is a std unit. There is something in the ECU that can decide if the engine is turning (air movement sensed ?) and it energises the relay.
jp 83 Euro S AT 55k

Alan

Crank rotation enables it via the ECU - but it no longer primes on ignition on like the old ones did...

Alan