1989 wedge 350i
Discussion
Hi, my poor wedge will turn over, start then dies, she will not run, I have changed my fuel pump as a precaution but no difference, changed ecu, airflow meter, still no difference, was wondering if it was a injection relay but can’t find it, got 2 ignition relays on the board so played with those, no difference, she’s being a naughty little girl, anyone have any ideas ???
)Check the red "relay" which isn't a relay but a bunch of diodes in the casing, just try pulling out, clean contacts if they look corroded and put back in to start with.
When you get to the post-turn-over stage start checking voltages - do you have pump supply? Do you have ignition supply? Supply volts for the ECU?
When you get to the post-turn-over stage start checking voltages - do you have pump supply? Do you have ignition supply? Supply volts for the ECU?
Cars only done 36000 miles original engine and had been great, did attempt to convert to quad carbs as got fed up with the efi system breaking down 5 times in one year, was told car with that original mileage would gain in price with the efi system back on, so be it the car is converted back, just this running issue which hast to be electrical in my eyes 
I guess you have had a read through this and other topics on here, as I understand it this had failed or was beginning to fail some time prior to me purchasing my car.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
I had rough running cutting out and hunting when it was running, after reading through loads of stuff on here, I found 4 issues, that seems to have cured it in the main. As it was a bunch of issues it took some time to track down one by one. There are of course all manner other electrical checks that can be carried out.
1- As mentioned above air leak, this was not obvious as it looked a good tight fit, but the replacement silicone hose to the AFM is a fraction short and has to be positioned just so, no air leaks.
2- There are a bunch of earth wires at the back of the passenger-side head that were loose, cleaned, and retightened. This caused the car to stall.
3- The idle adjustment screw kept winding itself in under vibration.
4- Some of the injector connector wires under the boots were poor, to a point where the insulation had disintegrated and the bare wires were touching each other.
That's about the sum of my problems as far as running goes.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
I had rough running cutting out and hunting when it was running, after reading through loads of stuff on here, I found 4 issues, that seems to have cured it in the main. As it was a bunch of issues it took some time to track down one by one. There are of course all manner other electrical checks that can be carried out.
1- As mentioned above air leak, this was not obvious as it looked a good tight fit, but the replacement silicone hose to the AFM is a fraction short and has to be positioned just so, no air leaks.
2- There are a bunch of earth wires at the back of the passenger-side head that were loose, cleaned, and retightened. This caused the car to stall.
3- The idle adjustment screw kept winding itself in under vibration.
4- Some of the injector connector wires under the boots were poor, to a point where the insulation had disintegrated and the bare wires were touching each other.
That's about the sum of my problems as far as running goes.
It's a shame I can't hear the sound on your video but this does sound like a problem I had myself just last week...
The engine would fire on the starter but would not continue after I released the key.
In my case a simple solution - some idiot had forgotten to connect up the ecu after checking for poor connections to and from the TPS.
So because it is cranking, the cold start valve provides fuel and the fuel pump is energised, but as soon as cranking stops, there is no signal to the individual injectors, so it dies.
If as has been said just now, if there is an air leak, the AFM may not be opening enough to energise the fuel pump, also if there is no connection from the coil to the ECU then the ECU won't fire the injectors.
Quick test, take off the airfilter, jam open the flap a little bit (gently) and the fuel pump will (should) now be active and you can hear it. It it doesn't catch after cranking when doing this then the problem lies with the ECU (e.g. power and or coil connection).
Hope this helps :-)
The engine would fire on the starter but would not continue after I released the key.
In my case a simple solution - some idiot had forgotten to connect up the ecu after checking for poor connections to and from the TPS.
So because it is cranking, the cold start valve provides fuel and the fuel pump is energised, but as soon as cranking stops, there is no signal to the individual injectors, so it dies.
If as has been said just now, if there is an air leak, the AFM may not be opening enough to energise the fuel pump, also if there is no connection from the coil to the ECU then the ECU won't fire the injectors.
Quick test, take off the airfilter, jam open the flap a little bit (gently) and the fuel pump will (should) now be active and you can hear it. It it doesn't catch after cranking when doing this then the problem lies with the ECU (e.g. power and or coil connection).
Hope this helps :-)
Another quick ECU test after this is:
1. Ignition on
2. Rotate the throttle by hand quickly at least 90 degrees
3. You should hear the injectors click.
This test checks the TPS, the ECU (under static conditions, and the injector output drivers), and (some of) the injector wiring, all in one go.
1. Ignition on
2. Rotate the throttle by hand quickly at least 90 degrees
3. You should hear the injectors click.
This test checks the TPS, the ECU (under static conditions, and the injector output drivers), and (some of) the injector wiring, all in one go.
crazysilverback said:
Here is a short video of my issue, starts great but then dies, fuel??? I’m wondering when fitting efi system back in I accidentally put fuel pipes wrong way wound, would this cause this situation? 
Hi Did you put the fuel lines back?...it should be feed to fuel rail and return to fuel pressure reg...if you have it plumbed in then you are only getting a dribble of fuel...might run a 5cc RC engine but not a 3.5 V8
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