Imobiliser

[sirlisterofsmeg]

Right here goes.
Long story short.
Had to take my battery off last week and stcuk it on charge for a couple of days.
Now the car wont start.
It turns over but doesn't fire at all.
I think it is something to do with the imobiliser
Has anyone got any ideas before i pull my hair out.
(I have already changed the Fuel pump relay)
Thanks
Mat

 

[Indi9xx]

What year is the car?
What are the option codes (white sticker by the spare wheel, or the front of the service book)?
Has it got an aftermarket immobiliser fitted? if so, what make?

You may have one of three factory or dealer fit immobilisers... it can get very messy very quickly with each system operating in its own way, immobilising different circuits.. Firstly check to see if it has fuel getting to the cylinders (pull a spark plug and smell it), then see if the car has a spark.. then report back here

 

[peanut]

Mat it would help if you tell us which 944 model you have and if possible which manufacture/model of immobiliser.
Sometimes removing the battery can reset alarms and immobilisers . Do you know if the car is fitted with an alarm system ?

If you look on Clarkes garage website in the workshop manual section there is a discription of how to make and fit a 3x way bypass in place of your DME relay. The bypass should supply your fuel pump and ECU which controls the ignition system . This should allow your car to start. Its an easy place to start .

 

[Mike_Pollock]

Its a square dash '83, so I dont think it has a factory alarm, so I'd wonder about the pick ups.

Does the tacho needle bounce?

 

[sirlisterofsmeg]

Sorry for the lack of info guys
As Mike says its a
1984 2.5 NA

Traced some wires back to a black box under the dash
Retro fitted
MI 600 immobiliser
Found a manual & Wiring diagram for it
So far
Fuel pump seems to be working (Can feel it when i youch it)
Have spark as well.
Yes Mike Rev counter bounces when turning over.
Ran out of light & patience
Back on it tomorrow afternoon.

 

[peanut]

even early cars can still sometimes have redundant aftermarket alarms . [] I remember reading on rennlist of a 944 having problems with a redundant alarm/immobiliser reactivating itself when a new battery was fitted.My car has 2x immobilisers fited. []

Anyway back to the problem.

If there is a spark at the plugs when cranking then the DME relay must be working and the ECU also.

If you can hear the fuel pump running whilst the engine is cranking then it would suggest that the fuel system is losing pressure .When the ignition is switched on the fuel pump should run for about half a second to build up sufficient pressure in the fuel rail for the injectors to work . The pump shouldn't be running continuously before the engine is running.?

Have you cranked the engine and then checked the plugs for fuel? that should be the next step.

If you fit the 3x way bypass as suggested, it will bypass many componants in the starting process. If the car then starts it will narrow down the number of components that will need to be checked . If it doesn't start it will still be a helpful diagnostic test.