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Discussion Starter #1
Hey all, this one will be a bit different for you all.

I have a 93 V6 155 and it's not firing on number 2 and 5.

The problem started before i even got her. The previous owned had it running on only 4 cylinders. He found that the injectors were blocked so got them ultrasonically cleaned, replaced the fuel filter with a OEM part and cleaned cleaned the fuel lines out and then it was running sweet again.

When i bought it it was running fine. Took it for a bit of a drive and after that it wasn't the same again. During the drive i noticed i was dropping oil pressure at times so took it easy and checked the oil. The oil was within the min and max level so didnt think too much of it.

Got home and topped it up anyway and now oil pressure is fine but she is only running on 4 cylinders. Pulled out the plugs and they were all suffering from carbon fouling and there were 2 different brands in there so replaced all the plugs this morning but still not going.

Pulled each lead off individually and found that pulling #5 and #2 off made no difference in how it runs. Pulled the #5 plug out and it had fuel on it so thats getting fuel. Checked the new spark plug and it still sparks so i'm getting fuel and spark so it must be compression yes? i have no way of checking compression (unless there is a DIY way?) so just not sure what to do next?

Any idea anyone?

Regards

Ned
 

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you can buy a compression tester for not much money, it screws into the spark plug hole, simply disconnect the crank sensor and have a mate crank it over, see where the gauge goes to, do it for all six and see what the differnaces are :)
 

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Aye! The beast sounds like it has a problem with those middle pots alright.

The TDC sensor plug is just above the steering pump (lower left hand side of the engine bay as you look into it).

It's a weird one though, as the electrics (relays, coil, sensors) and fuel (filter, pump, lines) serve all 6 cylinders. Middle cylinders do catch more wear for some reason but for them not to be firing at all sounds a bit severe. Compression check would have to be the next test.


Ralf S.
 

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If it was the injectors, moving them to a different cylinder should move the problem. Might be worth a try though to see what happens.

I'd suspect though that there's something going on with 2 & 5 that is making the injectors foul.


Ralf S.
 

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Discussion Starter #6
All the injectors are filled with crap just like before i got the car. 2 and 5 are just the worst. I had the tank quite low when i was giving it a bit of a thrashing so it probably scooped up some more stuff out of the bottom of the tank.

Will take every thing fuel related off the car and clean it intensely so that this wont happen again. That plus oil change, plug change etc should see some new life brought into the old girl :)
 

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Good lad! At least it's nothing too mechanical (expensive!). Stick a new fuel filter in there.. nobody ever changes the cannister on the '55 and yours is probably full of poo.


Ralf S.
 

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There shoudn't be anything solid getting past the (new) fuel filter really. What sort of crud are you finding in there?? Presumably whatever it is, is visible in the filter baskets on top of the injectors. Things that spring to mind...something wrong with the fuel, flexible fuel lines perishing (real stretch that one).

As Ralf says, try moving injectors about. Also, don't forget that once a plug has been thoroughly soaked in fuel, it's not likely to ever be right again.
 

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Aye! Good one! The fuel filter should be keeping the rubbish at bay at that end... maybe the problem is originating from the inlet side. Try clearing your oil catcher out...

Ralf S.
 
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