Outer Limits 4x4 Board

Thought I might try posting this here because I have spent ages trying to figure out why its not firing.

The ignition pulse is working, the computer has power, all the grounds are good the fuel pressure is at 44psi, the ignition is all good (new leads and plugs).

I cant figure out why the computer isnt firing the injectors unless its a faulty computer, but that means that 2 of my computers that worked a year ago, arent working now?

The ignition does work because if you use a spray bottle to spray fuel into the manifold then it starts and runs pefectly.

The afm, tps and coolant sensor are all connected.

Can anyone help?

and its related to 4x4 because its in my s1 landy

How do you know its not firing the injectors?

Are you sure you have the fuel supply and return around the right way? The supply goes into the rail at the opposite end to the fuel reg. The Fuel reg is on the return line. This is the most comon mistake people make when doing an EFI conversion. Everything else seams good but they just wont fire.

ruff is probably on the money but I once had a problem with a vl because of the old alarm system.

Stupid question but is it all disconnected ?

Nick

OK, you say Holden 202 EFI, I'm assuming this is the black motor out of the VK?

And are you running the original Bosch LE-Jetronic system that came with this engine?

If you are, then the first thing to check is spark. The ECU controls fuel only and is triggered off the negative side of the coil. If the coil is on the way out, there might not be a big enough "spike" off the negative side of the coil to trigger the ECU. The other thing is that if there are any other things hanging off the coil -ve, like tacho, condensor, ignition module, etc they can sometimes load it down if the coil or tacho is dodgey. Try another coil if you have one, or try disconnecting everything except the ECU and the ignition module and see if it comes to life.

If you are running a system other than the Bosch or this isn't your engine type, then disregard my post....

Cheers

Dont they run a crank sensor off the back of the engine onto the flywheel or something??
been years but i think this tells the ecu the crank position and when to earth the injectors to allow fuel ????

like i said its been years

RUFF wrote:How do you know its not firing the injectors?

Because it will start if I spray fuel into the inlet manifold, and also with a screw driver between them and the ear you can usually hear them clicking, no sound coming from them.

Are you sure you have the fuel supply and return around the right way?

Yes, I have had this motor running in another land rover before.

CWBYUP wrote:Stupid question but is it all disconnected ?

Not a stupid question as it could be wrong for someone, but there is no alarm.

Micky-Lux wrote:OK, you say Holden 202 EFI, I'm assuming this is the black motor out of the VK?

Yes

And are you running the original Bosch LE-Jetronic system that came with this engine?

yep

If you are, then the first thing to check is spark.

sparks all good, it runs well when I manually put fuel in, plus new plugs and leads.

The coil is fine, and have tried it with 2 different coils with the same result. The coil is only on the basics (+ to dizzy, - to dizzy, + power supply, - to computer).

The computer is getting the ignition pulse, the grounds are fine, the computer has power, the only thing I can come up with is possibly a dodgy computer, but surely 2 of them havnt stuffed up in the space of a year with no use?

Dont they run a crank sensor off the back of the engine onto the flywheel or something??

No, its just a feed from the distributor.

Thanks for all the help.

Cheers
Turoa[/code]

OK, you any good with a soldering iron?

If you open the ECU up, you will and have a look at the opposite side to the components first, you will see a heap of links (soldered bits with a piece of wire going to the other side of the board). Very prone to dry joints. I'd recommend resolder them on both sides. Also you will see what is known as a Hybrid IC, a sort of ceramic long thing encased in a plastic bit. You'll recognise this as there are a heap of solder joints in a row going to this thing. Re-solder it too. And also the connector, and there will be a power transistor attached to the heatsink. Resolder it also. That usually covers most dry joints that stuff the ECU's on these things. Other than that, there's not much else to go wrong with the ECU.

I used to repair these things for a living once, and I know what my boss used to charge for them. Honestly, the ECU's arent' worth what the repair costs these days. and with the age of them, if you go to the wreckers for one, chances are it will have the same problems.

Turoa wrote:

RUFF wrote:How do you know its not firing the injectors?

Because it will start if I spray fuel into the inlet manifold, and also with a screw driver between them and the ear you can usually hear them clicking, no sound coming from them.

Are you sure you have the fuel supply and return around the right way?

Yes, I have had this motor running in another land rover before.

Spraying fuel in the inlet only tells you it has spark. Yes you may hear the injectors click but they will only click if they have fuel pressure behind them.

If the fuel supply and return is the wrong way around then you have no fuel pressure at the rail.

Ive done heaps of EFI conversions and i have encountered this problem on more than one occasion when not giving it much thought when fitting the fuel lines. I have also found this problem when others couldnt get an EFI conversion running.

Another thing to check is 12v to the injectors... No power, no click. The ECU earths the negative side of the injector to make it pulse.

Checked EFI relay lately?

sparky! wrote:Checked EFI relay lately?

Relays fine.......

But have a new problem. I was thinking the injectors werent firing, but my dad went over the whole computer with the oscilliscope and everything was working? so then we plugged in another set of injectors, and it was firing fuel (into a bucket)

But then put those injectors in and its really overfuelling again :(

But when you unplug the fuel pump after letting it build up pressure it runs and idles fine?

How long has it been since the engine was fired up?

I had a problem once in a old celica where the import engine wouldn't fire. The injectors had gummed up.
I rigged up a couple of leads and tapped them on a 12v power source. I did this until I felt/hear the soliniods click.

Since the computer can get the new injectors firing then this may be whats wrong with the old ones.