Injectors misbehaving but trying to understand the numbers

[darbuck]

Hi Lads I bought this just in case I need to do any more injectors. It's reasonably priced at the moment.

https://www.ebay.ie/itm/354756868208?mk ... media=COPY

[darbuck]

Hi all I finally pulled the head and tapped out the rest of the injector. I will post up more later

[MattBLancs]

Good progress, bet you are more than glad to finally have that broken bit out!

How is the head / inlet ports for filling up with crud? Much cleaning out to be done there?

[darbuck]

Hi Matt I meant to say I still have to drill out the sleeve. The injector ports need to be cleaned and reseated. The head is bit gunky but apart from that seems fine. I have to do the valve stem seals . There was oil pooling in cylinders 1 and 4. So loads left to do fighting the steering rack today. I want to get it off the car so I can work on it in the shed out of the rain.

[darbuck]

Hi All,
I gave the head to my mate who has a milling machine he will do it for me on Saturday. Progress is slow, I bought a load of bits on mister auto usually grand but parts missing head and rocker gasket . so needles to say I am bit peeved.

[darbuck]

Hi all got the head back this morning no more stuck injector woo hoo . I need to do the valve stem seals which should arrive over the next few days so I will disassemble over the weekend and give it a good clean, nearly there now.

[darbuck]

I started pulling the valve stem seals out and decided to pull the valves while I am at it there is a significant amount of carbon on them and the cylinder three exhaust ones were particularly bad. it makes me think the injector was bad a while. I am happy to take it apart but putting the fiddly valve collets back on is a bit worrying for me I don't do fiddly too well. I can be a bit hamfisted and I am half blind at this stage aswell. i needed to do it though because of the leak down on cylinder 1 and 4 and I want to see if I did in fact bend any valves when I had the issue with the timing.

[Steve Walsh]

I started pulling the valve stem seals out and decided to pull the valves while I am at it there is a significant amount of carbon on them and the cylinder three exhaust ones were particularly bad. it makes me think the injector was bad a while. I am happy to take it apart but putting the fiddly valve collets back on is a bit worrying for me I don't do fiddly too well. I can be a bit hamfisted and I am half blind at this stage aswell. i needed to do it though because of the leak down on cylinder 1 and 4 and I want to see if I did in fact bend any valves when I had the issue with the timing.

Put a bit of grease on the valve grooves and use a small magnetic screwdriver, the grease will hold them in place. when you release the compressor just check that they are seated.

[darbuck]

Thanks for the tip Steve

[darbuck]

Hi all just finished stripping the head ready to be cleaned. Some photos of the valves they are really nasty.

[MattBLancs]

Well any amount of cleaning can only help there! It's a grim job (the DV6 was similar)

Inlet ports (best viewed looking in from the removed valve hole) will be similar I'd say. Cleaned up whatever I could reach.

Old toothbrushes can have the handles reshaped with a heat gun = clean round corners

[MattBLancs]

From memory some were worse than this (but it's hard work taking pictures when you're elbow deep in the grimy black muck!)

Here's a before and after, bench grinder wire wheel was weapon of choice:

[darbuck]

I bought some velcro scotchpads and used them to clean the valves. I put valve stem into a screw gun and lightly cleaned them up with it and then a 3000 grit emery pad to polish them. I am just finished for the day, if I suggest going back down to the shed I think I'll be strung up. I will post up pictures of the cleaned valves when I go down later or tomorrow. I did have a bit of an accident earlier and knocked over the box I had the valves pushed into. Three of the intake valves fell out , how much do I need to worry, will lapping the valves alleviate the risk of issues from this.

[MattBLancs]

I'd definitely lap the valves back in (would do so anyway, it's unlikely the engine will be apart again to this extent in its lifetime!)
But me being me, I would also worry about it loads, very likely completely unnecessarily!

In theory valves and guides have working together since new, so makes sense to pair them up. If you're put a valve in again and there's massive side to side play = you are in the same boat (i.e. press out guides, press in new, ream to size = machine shop job) nothing lost at that point playing "musical chairs" and swapping the three about see if any fit better. I would not expect a massive variation in valve stem diameter (as otherwise the guide ream job would need to be linked to measurement of the valve stem it is to receive and ream diameter varied to suit)
All the above generally result of chin scratching and hypothesising.

Short version of my waffling is I would suggest a shrug, sip of your tipple of your choice then carry on!

[darbuck]

Hi Matt, thanks for that I was thinking as long as they are lapped and no significant play they should be fine. Shrug and sip of tipple had last night last night. I'll post up more when I get a chance.