It's time to eat my words, gents. It is not timing at all - it's fuel delivery, which goes back to the points that you all mentioned earlier about the LH or something fuel related. Arggggh. I disconnected the vacuum line that attaches to the master cylinder, and sprayed a bit of ether (starting fluid) into the hose, turned the ignition, and the car fired immediately, and ran until the ether was consumed.

I tried this twice. The second time with 30 and 87 connectors on the fuel pump relay bridged so that the fuel pump continuously ran. I let the fuel pump run for a few minutes, sprayed a quick shot of ether into the vacuum line, and reconnected it. I then turned over the car, and the it started right up, but was unable to stay running, so as you all alluded to earlier, it's definitely fuel delivery.

The following findings have me baffled:

The Noid light shows that the injectors are pulsing in unison with the rotation of the starter (while attempting to start), which is what I would expect. If the LH was faulty, wouldn't the Noid light either not light up at all, or stay on solid? Am I daft for thinking that this doesn't add up?

The injectors are getting 12.5 volts to them (tested one of the connectors with a multimeter), so that's good.

Ran makeshift negative wire (connected to fuel injector connector on one end) across fuel rail to hear if the injectors would all click at the same time, and nothing at all.

Unscrewed fuel rail and very high pressure mist came out (after trying to start), so there is pressure in the rails.

I would still like you to install your computers into a good running car ,
they dont have to be bolted down.

Yelowbird, (If i knew you i'd still always call you Yellowbird, great handle)

You are getting there, keep looking for the simplest solution first.

Could your fuel rail have an obstruction beyond the point where cracked?

When you say fuel mist came out, did you mean liquid fuel sprayed out?


Matt

Hey Matt,

If I ever get this thing running, maybe we will meet some day. I'm on the West Coast, though.


When you say fuel mist came out, did you mean liquid fuel sprayed out? > Well, I think it was a fine mist because I cracked it just enough to see if fuel would come out. That indicates to me that the system is pressurized. Had I continued, I imagine it would have gushed out in a stream with some authority until the pressure was released.

Actually, I believe I've secured someone in my area who can supply a spare LH to test with. It's just a matter of WHEN.....

Thanks all, by the way, for your persistence on helping me resolve this. I hope that once the resolution is found, that others in similar situation can benefit from the experience learned from this headache of an issue. :D

the better test is to put your computers into the other car that way if your car has damaged wires it wont damage the other computers

I looked back at your original post and it doesn't mention that you replaced the fuel injection relay.

Please do so before you go any farther.

are plugs wet after cranking? - did these injectors run in old engine? - they can click and the noid light can flash but if injector is clogged no fuel will actually be going into the cylinders - you can pull the whole fuel rail and put each injector in a can to catch gas - disconnect coil wire so there are no sparks - and then crank it actually see if fuel is being sprayed

This^^

Actually, I checked the spark plugs when I was checking for spark, and they seemed pretty dry, come to think of it. I will attempt to turn the car over again, and pull out a plug. These are NOT the same (36LB) injectors as was in the car when I started it last. The vendor replaced them for good measure (at the same time I got the replacement motor), as we had originally suspected that one of them was DUMPING fuel into the cylinder, which caused fuel lock. This turned out to be false. What ruined my original motor was a small washer that found its way into cylinder three (3).

Stan you are a wealth of useful information.


You deserve this motor to run and run well. Keep us posted Yellowbird.:):)

That's the first thing I would check !!!! " The fuel Injection Relay "

I believe you can jump that relay however I would just instal a new one .
it sounds exactly just like the one I fixed that turned out to be just that the Fuel injection relay

Hey aluminum. I replaced the relay last week with a new unit. Still doesn't start.

All,

Tonight for good measure, I swapped out the new replacement LH relay with a known good used one, and it still would not fire. I also cranked the motor over for a good 45 seconds, and removed a spark plug - no fuel on the plug, so definitely no OVER-fueling/flooding issues. I think we all agree (it just took me a while to fall in line with everyone else's thinking regarding this issue LOL) that this is most certainly fuel delivery (or lack of) issue. Hopefully, I'll be able to run the LH swap soon - namely, put mine in a known running S4.

Did you check the resistace of the injectors? I think the fuel rail lines have some sharp corners and I think small lines. Someone mentioned a possible blockage? Try using compressed air to blow out the lines. The fuel injectrs are fired via grounding by the LH, the injectors will always have voltage if checked for with a test light. Could have a failed regulator or dampers that have collapsed internally and prevented fuel flow(though i think this is unlikely).

Fuel pump, relay, etc?

Do this^ Yellowbird before the LH brain transplant.

Good luck and when she fires up and runs i want VIDEO!SmileWavy

OK, so thanks to a local 928 guy in my area, I was able to perform the LH swap test. Not only did I run my LH in his car (which started and ran just fine), but he swapped a spare LH which he tested in his car (and started and ran), but in my car, it would not start. The good news is that it rules out a bad LH, but now I'm just stumped. I cannot think of what else this could be.

The last test I can run is a fuel pressure test to make sure that its getting ~55 PSI during cranking, and the possible fuel blockage in the fuel rail(s) is a good tip to investigate. Other than that, I cant think of anything left to test. Just to re-iterate... the car DOES fire right up with a spray of ether, which proves ignition is OK.

Also, the shark tuner has some great on-board diagnostics. Temp2 sensor was reading the expected temperature. The Crank Position sensor was sending the correct signal to the computer while attempting to start. Other than fuel pressure, I'm out of ideas.

The saga continues..... :mad:

I ran a fuel pressure test at the rail and it's at 55lbs, which is what I expect when cranking over. Does anyone have any other ideas? I've literally checked everything, sans the injectors themselves.

The facts:

• There is spark at the plugs
• There is 12.5 volts at the injectors
• Noid light pulses as it should while cranking engine over
• Spraying Ether into the intake allows the engine to immediately start (ruling out faulty ignition)
• Fuel pressure at the rail is 55 lbs
• LH is confirmed to be fully functional

I'm most likely reaching here, but the front of the car is still on jack stands in order to get easy access to components under the car - and is at a fairly radical incline. I have not yet lowered it, because there are some things that I need to attend to after resolving the starting issue. The LCD panel under the RPM and speedo indicates that I need to check OIL in big bold red (despite having a full oil sump). Can the system send signals to keep the injectors from firing under certain conditions. At this point, I'm considering just about anything as a possible cause.

If the injectors are not strictly matched to their respective cylinders, would that cause an issue such as this?