Thread: EFI Fuel issues?

It could be a fuel pump. Easy way to check if you have decent fuel pressure is to push the Schrader valve in on the fuel rail (drivers side of the fuel rail) while it is running, or when the ignition is first turned on. It should squirt fuel a fair way - it should pretty much hit you in the face.

If you have a pressure gauge then all the better, but it should give you an indication.

Cheers - Gav

Well.. Yesterday I rang Justin Cooper and spent about half hour on the phone with him..

We checked fuel--fuel is a bit dirty, but not the issue, fuel pump itself is fine, has spark, getting plenty of air.. But it still idles perfectly fine, revs fine.. then just out of nowhere, sudden death usually after 1-30 seconds. Has spark constantly. He thinks it might be a little sensor (Water temp sensor?) on top or a vacuum leak, but to be able to diagnose it properly, I have to take the car to him.

Unfortunately, can't afford that, nor can I afford to get him out to the car (Collinsvale) to have a look, either.. so anyone here got any ideas?

More info:
12/87 RRC Hi-Line. 4 speed auto, white 4-door.
In the year before I bought it (Feb last year), it had brand new air con, distributor, as well as some other parts that I can't remember now.
New engine at 300,000 (430,000 on car), using a Disco block, same heads but shaved, rest of engine is new. All the lines and such look rather new.
I've put brand new plugs/leads on it, topgun 8mm and BPR5ES plugs in the past month.

Issue started happening after for some reason, the charge wire on my alternator had come loose (The nut vanished ), so I broke down.. jump started it twice with a lot of carrying on/back firing, then died (No wonder, we didn't discover the charge wire was loose till later that night when we went back with a mate who works at a wreckers..). This was about two weeks ago.

Fixed that, jump started it again, ran fine.. cue sudden death issue. Runs like a dream up until the point where it just -instantly- dies. No carrying on, no backfiring, just stops mid rev or mid idle. Idling or revving, makes no difference to the time before it dies.

It's really got me stumped.. I do have a parts car, but it's a 1980 2-door with a 3.9 carby in it..

Check the white/black stripe wire for tightness at the negative side of the coil. This provides RPM input to the ECU and its loss of signal means no fuel injection. Also this wire goes via a vacuum switch on the drivers side rear area of the engine, to cut off the injectors at high vacuum on over-run. You can bridge the two wires to ensure the signal gets through to the ECU. The car will run perfectly well without it.

Hey nick if ya need any bits for the flapper system I have a complete spare setup minus the maf


Adam

Hey Adam, cheers for the offer.. not sure what I need if anything at the moment.

Hi Bee utey, tried your fix, found that wire was loose, fixed it by crimping a new connection on to it, but it's still doing the "sudden death" thing..
Any other possibilities? It's also seeming to idle rather higher (1300 or so) than it used to, but still dies.

Originally Posted by Guillocuda

Hi Bee utey, tried your fix, found that wire was loose, fixed it by crimping a new connection on to it, but it's still doing the "sudden death" thing..
Any other possibilities? It's also seeming to idle rather higher (1300 or so) than it used to, but still dies.

What I'd do is rig a led test light on every circuit that may be at fault, e.g. injector positive, injector negative, ECU power, coil positive, fuel pump etc, hang the lamp where you can see it and watch for the exact circumstances of the fault. Your fault sounds typically like a loose connection or fuse, they heat up and disconnect, then reconnect when they cool down. I used a 12V led rocker switch for this exact purpose on a different vehicle that would randomly stop in difficult conditions.

The pulse rate and brightness of a led is a good indicator of injector function too. In the last vehicle I tested the led flash brightness would dip really low when the MAF randomly shorted the output to zero. Connect the circuit you want to test to the switch "+12V" terminal, earth the indicator lug, you can switch off each indicator as you narrow down the misbehaving circuits.

example switches:

4 X Oval Rocker Switch LED 20 Amps Illuminated Blue | eBay

BTW idle speed is a function of the air slide valve, front d/s of engine with 16mm black hoses in and out. Check for power here too.

Bit of an update..

Turns out the issue is a spark issue..

Hard to diagnose why because the car does -not- run an ignition module.. The ign module is sitting on a thick alloy plate on the front of the passenger wheel well and is earth, but isn't connected at all in any other way shape or form.. @_@

Finally got your email pics to work, and need more detail, IE the distributor itself? I am getting the impression it has been converted to run a later distributor with an attached module. Try attaching a decent earth strap or just a wire from the distributor body to a good earth on the engine itself. If the distributor body has poor earthing the module will not work.

JC