Rensb

84 944 n/a - Fuel pump not pushing fuel to the rail when starting (cranking). I have "Tach Bounce" (new sensors), I have spark. I've taken the fuel pump off, and connected it directly to a 12volt, and it runs. I also pulled the nut & ball off of the fuel rail, and ran the pump (connected to the 12 volt), and fuel ran through fine. I have a new DME relay, so I'm doubtful that's the issue. Could it be a grounding issue? (if so, what's the first one to check). Could it be stuck injectors? (all 4? - it has sat for 4 plus years - but the tank has been flushed-out during this process). My electrical knowledge isn't the best, so if I need to test for "Hot wires", or "Jump Fuses", please include some additional detail. Thanks

V2Rocket

fuel pump fuse?

Humboldtgrin

Ignition switch?

Rensb

Fuel Pump fuse - # 2 in the secondary fuse holder correct? It looked good (but I didn't pull it for a closer look). What does it get replaced with (amps?).
I would love it if it was something that easy.
I did see a ground point that was in the back hatch (between the tail lights / drivers side) that needed cleaning, so I Dremeled that this morning. I'll check out the fuse and let you know - I'm a little new to this site, an boards like this in general, so navigating the "How to Post" process is going a little slow for me.

V2Rocket

http://www.clarks-garage.com/

everything youll ever need to know

Rensb

I was hoping to avoid disassembling something. How difficult is it?
I've see the following on a previous post (This is a copy & paste from a user named Der Rennwagen) - I'm a little new to this, and I'm not sure how to embed links.

Disconnect the battery.
- Remove the steering wheel.
- Remove the turn indicator / wiper stalks and connectors.
- Remove the dash guages (two screws), and speedo cable
- Remove the white (brown by now) plastic spacer on the steering column shaft. Something the Haynes manual misses and this took me a while to figure out that it actually slides off.
- Unbolt the hex bolt that holds the lock assembly to the steering column on the left side.
- Remove the key tumbler and lock assembly, unplug connector.
- Remove the old ignition switch (small phillips screw on backside underneath) and replace with new unit.
- Reasemble in reverse order.

I understand these things go - any other tests I could perform?

V2Rocket

i wouldnt look at the ignition switch - it is working if you are getting spark due to the way the DME relay is wired.

Tom M'Guinn

How do you know the fuel pump is not working when you crank? I ask because you speculated that maybe the fuel injectors are stuck, which would be a guess for no-fuel in the cylinders (especially after sitting 4 years), but not a guess for no power to the fuel pump.

When you hot-wired the pump to run in the car, did you try starting the car? And/or have you checked the fuel pressure at the rail with a gauge while cranking?

If you haven't already, I'd start by confirming with a multimeter that pump is not getting power when you try to start the car. If so, then RL can help you test the points leading back to the battery to see why there's no power (e.g., harness wires, ground points, relay, etc.). If there is power and the pump is working, then you'd want to look downstream and figure out why gas isn't squirting out the injectors (e.g. clogged injectors, frayed injector connectors, bad FPR, etc.).

Do you have a multimeter and know how to use it to test for continuity, ground and 12v? It's not rocket science, but a skill that will pay endless dividends on these cars. Tons of good youtube videos, like this one:

Rensb

Tom M'Guinn - I like your logic about confirming that the pump is indeed getting power while cranking. I do have a multi-meter, and I had previously see the tutorial referenced. (actually I ran out and got almost the same meter demo'd).

I ran wires from the fuel pump terminals to the multi-meter where I could see the reading when I tried to start the car. I've got a steady 9v to the fuel pump. I don't know if that's good or bad, considering the other power consumed during the starting process.
The battery tests out at 11.83v while just sitting there.

I was not able to test the pressure at the rail earlier because the local Auto-zone pressure test kit didn't have an adaptor for a european car (I live in Michigan, that is to be expected in my neck of the woods). I can tell you that fuel did pump at a rate that would fill a 1/4 clear tube, and when I put my thumb on the end to contain the fuel, it sprayed like a garden hose. believe it or not, this was done on purpose to see if there was any pressure at all.

So, if volts is enough to pump fuel (at least to start with), and I believe there is pressure to the rail (again, not formally tested, but if I remove the nut at the end, a large amount of fuel will come out), then what would be the next steps to validate power to the injectors? I've seen a "Noid light" referenced online, would that validate that power is at least going to the injectors? If so, then what, pull them and have them sent-out to be cleaned, or is there a more home-grown solution that I could try myself? (Ultra-sonic Cleaner?).

I did check the fuses, and they were all good. The contacts were ok, but just to be on the safe side, I cleaned those as well.

I want to thank all who who have chimed-in on this topic. I truly appreciate the input and assistance.

Chris White

BTW - fuel pump fuse is also the O2 sensor heater fuse.....undocumented feature!

Humboldtgrin

You need a new battery it sounds like. <--Yodda...lol.

Rensb

Well here's the update..... I hooked-up a Noid light to 2 of the 4 injector plugs and it flashed while I was cranking. I would believe this is a good sign (power to the Injectors). So, does this tell me (a) - that the injectors are bad / need to be cleaned (this car has sat in a garage for a number of years prior to me acquiring ownership - an eccentric friend of mine had it, but rarely drove it) (I've already gone the route of replacing the speed & reference sensors - they are confirmed to work, and I have confirmed spark), (b) - that the 9 volts going to the original fuel pump isn't producing enough juice / pressure for the rail (any idea in the "Conversion fitting" that I would use on the rail for the Auto-zone fuel pressure test kit), or (c) maybe a combination of both (injectors & pump)
I'm glad I have evidence of power to the rail. Again, this seems like a good thing.
Well, it's up to the "Wisdom of the Crowd", Any suggestions on what to do next?

Humboldtgrin

When gasoline sits for a while it turns to turpentine and doesn't burn.

C ANDERSON

check and clean the ground between tailamps Had a customer car that would not crank some times . every time I would go check , it cranked. finally fuel pump not running , jumped DME still not running, check voltage and had 9 volts . check pos wire to ground had 12 volts . cleaned ground, then 12.5 volts pump ran , has not failed since .... knock on wood !

bw993

You need to check your grounds, if you are only seeing 9 volts at the fuel pump. As a simple test, use a wire for the ground straight from the car chassis to the fuel pump to see if you get more voltage to the pump.