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        General >> Problems >> Fuel injection connections.
        
(Message started by: emcscott on Jan 22^nd, 2009, 1:40pm)

Title: Fuel injection connections.
Post by emcscott on Jan 22^nd, 2009, 1:40pm

I just had a new Engine wiring harness fitted and the car now runs rough at anything more than very light throttle - I am concerned that the connections to the fuel injectors might not be in sequence. The cables are numbered one to six and my old harness was connected wire 1 to cylinder 1 etc but the article in here on HO2S Monitor shows a differrent order in the para headed OBOTO Syndrome - does anyone know what's going on here ? Please !

Title: Re: Fuel injection connections.
Post by scorpio_man on Jan 22^nd, 2009, 2:03pm

hi there

just to confirm, are you talking about the actual injector or the spark plug (from the coilpack)?

cheers

Title: Re: Fuel injection connections.
Post by gozz on Jan 22^nd, 2009, 9:44pm

emcscott.
The 12valve engine fires each bank seperately but all three at once,therefore you only need to connect each bank correctly,the 24valve fires individual cylinders,so is a little more complex.
GOZZ.

Title: Re: Fuel injection connections.
Post by emcscott on Jan 22^nd, 2009, 9:54pm

I am talking about the electric connecting plugs that go on each of the fuel injectors on a 24v engine. Each plug has a numbered label.

Title: Re: Fuel injection connections.
Post by gozz on Jan 22^nd, 2009, 11:22pm

emcscott.
There is a possibility that you are experiencing the same problem as I once had.The loom was in a terrible state so I remade it,whilst doing so noted that some of the injector wires did not correspond to the injectors to which they were attached.Little heed was paid to this,and the injectors were duly wired up as per cable colour codes in our wiring diagrams.The engine then ran in a hopeless manner,and as the car was to be used for spares anyway,the problem was not pursued,the vehicle is still with me,and the engine is in it ! ???
GOZZ.

Title: Re: Fuel injection connections.
Post by emcscott on Jan 22^nd, 2009, 11:28pm

Thanks Gozz- good point I'll compare the wiring colours with the wiring diagrams. I am still puzzled by the article entitled 'HO2S Monitor' which contains a table telling which wires go to which cylinders and it just doesn't compare to what mine was and it used to run beaut !
Tommorrow I'll investigate the new connections.

Title: Re: Fuel injection connections.
Post by gozz on Jan 22^nd, 2009, 11:47pm

emcscott.
Just had a look at the mysterious 'OBOTO' syndrome for the first time ! this could be the answer to our problem.It seems incredible that the numbers on the wires do not all correspond to the relevant injectors,in fact bloody barmy ! So in my case it could be that the wiring diagram relates to the numbers on the wires and not the injectors,in your case it seems you must follow the barmy instructions shown in the text.We live and learn eh !
GOZZ.

Title: Re: Fuel injection connections.
Post by emcscott on Jan 23^rd, 2009, 9:05am

well I would like to know where those figures came from - my old harness was connected Wire 1 to cylinder 1 etc for all cylinders and it was fine. I have now found the colour coding in the wiring diagram and I,ll be interested to see how that compares with the numbers on the wires when I get it all apart - if it stops raining some time toda!y! Thanks, Malc.

Title: Re: Fuel injection connections.
Post by emcscott on Jan 23^rd, 2009, 9:08am

Wish I hadn't thrown the old harness away ! Malc

Title: Re: Fuel injection connections.
Post by emcscott on Jan 23^rd, 2009, 10:00am

Hi Gozz - can you tell me how bad was your engine when the connections were wrong ? Mine runs fine at tick over and driving it gently round town it s ok - but if I start to give it a bit more power it sounds gruff and 5 cylinderish although there is still a lot of power. Actually my biggest fear is that I've blocked one of the cats when I drove it home on 5 cylinders before getting the harness replaced.

Title: Re: Fuel injection connections.
Post by gozz on Jan 23^rd, 2009, 12:12pm

emcscott.
Mine was misfiring and wouldn't idle properly,yours sounds like another problem !
I've got a new loom here that I bought from Shaun some time ago.If you need information off it I will dig it out,I seem to remember that the numbers on it correctly matched the wire colours as per diagram.
GOZZ.

Title: Re: Fuel injection connections.
Post by emcscott on Jan 23^rd, 2009, 5:34pm

Thanks Gozz - I'm booked in for a diagnosis session on monday so I've decieded to wait and see what they come up with before I go pulling things apart again!

Title: Re: Fuel injection connections.
Post by emcscott on Jan 27^th, 2009, 7:01pm

Success ! The diagnosis with the Laptop found nothing wrong and showed the cats and sensors were working ok. They traced my problems to a vacuum pipe not properly connected - and all is now as it should be. So my injectors are connected with wire 1 to cylinder 1 as before and that works for me ! Thanks to all who contributed Malc.

Title: Re: Fuel injection connections.
Post by gozz on Jan 27^th, 2009, 8:34pm

emcscott.
I bet that,s a relief eh :)
GOZZ.