Starting problems

[JP1]

Hi

I've just installed a 'new' engine in my '97 Mexican Airtop Beetle (engine code ACD225199 with the later dist etc) . Engine was complete therefore connected up and hoped it would start and run ok. The engine turns over ok and it is fuelling ok but no spark. The alarm has been removed and the system has been hotwired in the fusebox - therefore the petrol pump runs constantly. I've tried changing the ECU / Transformer (ie Coil) to no avail. The new engine has only done about 15k miles so I'm at a loss what could be wrong. I'm wondering whether it could be the hall sender? or has the removal of the alarm system caused a problem with the ecu? I do have the alarm box but when I have fitted it to the car the alarm works but on switching on the ignition it is clear that the fuel pump doesn't operate....I've checked the wiring and apart from the connection in the fuse box (which has to be removed when installing the alarm) everything appears stock.

Any help would be greatly appreciated.

JP1

[Red1600i]

Hotwired pump... hmmm, why? It's just a wire bridge with 2cm length necessary to replace the alarm system. So why? Has somebody killed the ecu control for the pump?

But if you just wired the pump, then there is still no power for ignition, the alarm system controlled pump and power supply for the ignition ... that's why it's not working. And a pump without control will make a lot of fun if you have a hard stop...

The documentation how to replace the alarm modul is on this site...

[JP1]

Thanks for the reply.

I reckon that someone has killed the ECU control for the pump which I presume is the reason why it pumps constantly ? That is , my Golf for example pumps for a second or two but then shuts off once pressure is raised on the turn of the ignition. it starts pumping again on starting the engine. The 1600i pumps continuously once you've switched the ignition on . whilst the return copes with the excess I can't imagine this is right (or I might be wrong - should it pump constantly?) Regardless it would clearly start if there was a spark but there isn't so ....In terms of the module itself then that's an easy fix - it's a plug in BUT I presume there is an ecu adjustment etc. If you direct me to the correct source on the site that would help plus any further advice - whilst I'm very conversant with the old style Beetle this is totally new to me and of course without the right kit I'm struggling. At the same time the offer locally for a solution to this is rife with danger - know it alls knowing nothing and serious expense if you are not careful! So at the moment it's self help until I can source the problem - the annoying thing is that this is a very good engine and I suspect that all it's sensor are all in working order (though as I note below there could be an issue with the hall sender?)

[Red1600i]

Look here...

http://1600i.de/1600i-elektronik/Alarma ... age97.html

connect pin 22 and 23. That's all. Then the pump and the ignition ist reactivated.

And remove any other modifikations...

Pin 22 and 23 are the ecu control for the pump relais. Dont mess around with this signal, its direct part of the ecu and will only survive with currents less than 200mA or the transistor inside the ecu dies. So: check wether somebody has modified this signal...

[JP1]

Thanks a lot for the link very helpful.

Whoever did the hot wiring on mine linked 23 with 12 (not 22) and I'm now concerned that it may have cooked the ecu. Worse, I had a spare ecu and tried it without realising the consequences of the aforementioned wiring!

Having said all this I have made some progress. I disconnected the feed to pump and inserted the alarm module and hey presto, the pump worked as I expected - cutting off once the pressure was up on turning the ignition. I still don't have a spark though which means I've got a component fault. I have tested the hall sender as suggested on this site - it would appear that the injection system squirted petrol ok BUT there was no 'click' in the system at all. Now the question is whether the adverse wiring has caused irreparable damage to the ecu and therefore is failing to send a signal through OR could the hall sender be at fault?

any thoughts on this would be much appreciated

JP

[Red1600i]

If you turn the motor by hand and the pump starts to move each time the hall sender is triggered... then the hall sender is ok.

A very common problem is the ignition transformer. If it is still the massive alumenum TELEFUNKEN unit, replace it. The part is very cheap to get on Ebay, it is identical to the Golf III and Passat ignition units. The problem is corrosion inside which destroys the coil.

http://www.ebay.de/itm/ZUNDTRAFO-ZUNDMO ... 588cb66dbf

You could check the power supply for the ignition transformer. 3-pins. 12V (black), Ground (brown) and Trigger (black/green). Trigger will flash if you use a very small lamp (less 1 W), the signal is low active, connect the other side of the lamp to 12V

[JP1]

Got it! Combination of the appropriate hit-wiring and establishing that one of the wires in the main plug had become dislodged solved the problem - engine fired up instantly and was purring!!

Thank you very very much for the help on this.

JP