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Model specific boards => Golf mk2 => Topic started by: stew8vmk2golf on 25 June 2003, 17:46

Title: 8v wont start
Post by: stew8vmk2golf on 25 June 2003, 17:46
 :'( can any one help me, i recently swapped the engines over in my car adding a 1.8 mk2 8v gti (digifant) engine to my car. I swapped the whole thing including all the wiring looms and the fuse box. Now that its in my car it wont start. The engine seems to flood all the time. If i disconnect the wire to the main fuel pump the engine eill eventually start and then run for a while, but if i connect the pump again, it stalls and floods. Its been suggested that its the ecu. But i've put a replacement on it and it still does the same thing. When the engine was out i changed the clutch and the timing belt. Can anyone help me with this problem as i really want to get the thing running again.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 18:00
Did you miss a connector somewhere or is one loose maybe?

Does sound like something isn't talking to the ECU and telling it that there is fuel there.

I'll have a look in the Bentley see if that sheds any light..........
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 18:06
the connectors are all on and secure. the only thing that isnt connected is a two pin connector behind fuse box that was never connected in the first place. The connector on the side of the fuel injector rail is a different colour to that suggested by the majority of wiring diagrams, being a black/yellow and a brown/yellow wire. its as though it can cope with a small amount of fuel but not the full amount as though the injectors are letting in too much. Are they constantly open?
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 18:18
Have you interrogated the on board diagnosis?
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 18:21
the what. please dont tell me that has something to do with the dash. as i'm currently swapping over to a mk3.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 18:24
Bare with me, I'm getting this info from a Bentley..........which incidently is American so it may be slightly different due to the tighter emission laws in the states.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 18:28
Have a look here, see what you make of this.............

http://homepage.ntlworld.com/richandhazel1/DigifantOBD/ESIS.htm

Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 18:45
on the ecu it says its the digifant II type. the old instrument cluster didnt have any thing that was labelled check. The only lights which lit up were alternator, oil and temp.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 18:51
Hmmm, I have something on difigant 2 too........back in a mo.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 18:57
The digifant 2 on board daignosis only applied to Californian models so that doesn't help much.
There is a troubleshooting page but it doesn't mention anything about overfuelling..........do you want to have a look at it anyway?
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 19:00
yeah please mate
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 19:02
Also just found this:-

To ensure good starting and smooth running, the Digifant II system provides extra fuel to a cold engine. The coolant temperature sensor gives the control unit information on engine temperature. The control unit, in turn, makes an adjustment to injector opening time to provide the necessary richer mixture. For additional cold running driveability and fuel economy, the intake air preheat system warms the air entering the engine.

Coolant temperature sensor maybe?
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 19:16
Testing the temp sensor:-

http://homepage.ntlworld.com/richandhazel1/DigifantOBD/TempSensor/ESIS.htm

and the troubleshooting:-

http://homepage.ntlworld.com/richandhazel1/DigifantOBD/Troubleshooting/ESIS.htm


Hopefully they've come out OK.
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 19:28
couldnt display the graph for temp vs resistance
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 19:30
are the fuel injectors supposed to have a constant live feed of is it supposed to fluctuate. the connector to the side of the fuel rail seems to have a constant live feed of the same voltage.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 19:38
Quote from the manual answers that:-

The injectors used by the Digifant II engine management system are electrically operated solenoid valves which are switched on and off (open and closed) by the Digifant II control unit



are the fuel injectors supposed to have a constant live feed of is it supposed to fluctuate. the connector to the side of the fuel rail seems to have a constant live feed of the same voltage.
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 19:42
Just sorting out the graph.........
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 19:47
couldnt display the graph for temp vs resistance


Hopefully the graph will show here:-

(http://homepage.ntlworld.com/richandhazel1/DigifantOBD/TempSensor/Untitled-1.jpg)
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 19:55
thanks for that. the sensor is working correctly. the injectors seem to be recieving a constant voltage through the connectors. Any ideas why this is?
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 19:58
2 secs..........I have something that may help you in fault-finding the problem..........
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 20:05
Have a look at this:-

http://homepage.ntlworld.com/richandhazel1/DigifantOBD/Tests/ESIS.htm

Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 20:10
would you be able to post the pics up here or e-mail them to me as they seem not to be coming up again. theres probly something wrong with  my computer as well as my car.  j_stewardson@hotmail.com
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 20:13
Thats odd.............I checked it with my other PC too ???
Title: Re:8v wont start
Post by: richandhazel on 25 June 2003, 20:18
Just sent you an email...........
Title: Re:8v wont start
Post by: stew8vmk2golf on 25 June 2003, 21:10
 :'( done all the testing and everything seems to be working correctly. it therefore seems that there may be a problem with the euc its self. I've just bought a replacement though and its supposed to be in perfect working order. Are there any reasons why the ecu may have blown. Its been suggested that the wiring for the earth may not have been connected properly, but i've checked that and it seems ok.