jbob

could you guys help a brother with a checklist of what else I could do. (924S btw)

put the car back together, all the lines seem like they are going to the right place and am rather proud of my new fuel lines. plugged in the fuel pump wires in the rear

have plugged the fuel pump relay in several times double checking orientation from that horrible upside down position.

have filled the car with 3-4 gallons of fuel. and now am turning the thing over and over hoping for a spark. tapped the spark plugs to make sure they are seated and rechecked injector wires as well. i didn't check, but witch hunter injectors don't have any seal or anything to peel off do they? i didn't see anything, and just unwrapped them from the bubble wrap and put them on the fuel rail and plugged them in.

any other tips would be great. super excited to hear this thing turn over

jbob

do i need to prime the fuel pump somehow?

squeezing my new rubber fuel lines in the front of the engine they don't seem full yet...

jbob

Checked the fuel pump wires - german engineering made the screws and copper contacts different sizes so there was no way i could have had the positive and neg wires on the wrong terminals.

Had a spare dme put it in, still no start. Tried the paper clip jump technique, still nothing. Then decided to give the poor dirty old thing a nice wash. Hopefully there is a technique i havent tried. Just sitting in the car turning the key felt really good and i am loving the look of my fresh new fuel lines. If anyone has any things to try i would love to hear em!

konakat

I would try some starting fluid. If it starts, it definitely is a fueling issue. If not, normal no-start debugging, starting with reference sensors. I've seen a lot of people get burned by having something completely unrelated go wrong and be on the wrong track with their debugging.

jbob

Thanks man you are always super helpful. As far as starting fluid whats that entail?

For checking sensors its possible that something isnt plugged right and is tripping the computer?

Also, I see the tach bounce when i try to start. As far as what was unplugged i did also replace the AOS and am down to bare wire on that sensor thats between sparkplug 1 and 2 on the engine block, but i think that its still plugged in (could this even cause a no start?)

Thx again, just another head scratcher and a chance to learn

fiily

Any pics you could take to show us what your saying would be great.

jbob

Can do. Its all buttoned up, everything seems plugged in... Not sure what a picture would show unless it was a closeup of an unplugged sensor wire or spark plug wire.

Is there a safe way to check if fuel is making it up to the rail and the fuel pump is activating etc?

Are there any sensors that if off or tripped just kill all fuel delivery?

Anyway thanks, feel super close but stuck again
Also any clues to check as far as the sensors etc go?

odonnell

http://www.arnnworx.com/catalog/inde...9#.V4nLuPkrLIU

Otto Mechanic

I'm not sure about the 924 (don't have mine anymore) but the 944 and 928 both have a cap nut on the fuel rail that has a trapped ball bearing under it. If you remove that cap and ball you can screw a fuel pressure gauge onto that port and test pressure delivered to the rail by the pump. There are people who permanently install pressure gauges at that point in the system but it's not a real good idea since it introduces another place fuel might leak in the engine bay.

There are several regulators/dampers in the system, any of them might fail and cause pressure to be too low to operate the injectors so checking for correct pressure at the rail is a good place to start.

jbob

ok so some developments

i brought out some rags and opened up one end of the jumper to the fuel rail - DRY AS A BONE, and then where the fuel hose from the fuel pump meets the damper on the fuel rail - also, DRY AS A BONE.

I have two DME, one might be less good, but a previous mechanic gave it to me instead of throwing away, anyway I have tried that as well as my newer one, and checked that the fuel pump is plugged in.

what else could be causing my fuel pump to give no fuel. I have about 3-4 gals of fuel in the fuel tank. have a new strainer, a new hose to the fuel pump (there is a bit of a low point in that hose between the tank and the fuel pump but very minor, you would think the fuel would still be reaching the fuel pump by gravity.

on the plus side I am getting super fast with putting the DME in and out - I envy you guys with the fuse box topside.

anyway, looking for a clue on why no fuel to the fuel rail. thanks so much

odonnell

Jumper the DME relay and see if you can get fuel into the rail. It's not the easiest job with the early relay panel. My favorite technique is to take a spare DME relay and modify it internally (soldering jumpers) to connect terminals 30, 87, 87b together...then you just have to install the relay instead of dicking around with spade connectors in the cramped area.

jbob

would this just mean making a more beefy soldered version of the paper clip technique on the white surface where the terminals come out? basically taking wire and joining the 3 bigger ones #2, #4, #8 (30, 87, 87b)?

its just weird because my main DME that was in there was working before this fuel line project. is it possible to have a working DME that just doesn't activate the fuel pump?

another person told me to check the power to the fuel pump - would that just be turning the key to the right without turning the car over and using a multimeter? (gotta get one and learn some basics there)

Otto Mechanic

It's easier than that, you shouldn't need a meter, you ought to hear the pump come on. Don't try starting the car, just turn the ignition on. You should be able to hear the pump.

If the pump doesn't come on then go with the meter. If you have power and the pump isn't running it's a dead pump. If the pump is running I'd start looking for blocked lines. If you don't have power to the pump with the ignition on, it's obviously an electrical problem and I'd start by looking at fuses/relays.

Otto Mechanic

Have you tried replacing the DME relay?

jbob

Just before heading out for the day i cleaned the fuel pump fuse with contact cleaner and then turned the key and heard dripping, and i saw the leak coming out of the fuel filter side of the hose connecting the pump to the fuel filter (I had filed down the hex because it was stripped and maybe didnt tighten it in all the way long ago when i was doing that step.). Happy that the fuel pump is making that mess and curious if it will start once i tighten that up. Before cleaning the fuse it wasnt dripping - and a little dripping was something i expected. Excited to get back on this. Feels like i might be close