I finally got around to pulling my intake manifold so I could install a new set of injector o-rings, gaskets, patch up my wiring harness, and do some much-needed under hood cleaning. So far it's all been pretty straight forward, but messy and time consuming. I'm wondering if there's anything else I should take care of before I sew everything back together? Also, any tips on cleaning dirty valve stems would be greatly appreciated.

Thanks

Finished putting it all back together last night. It took longer than expected, but then I took my time poking around, cleaning and whatnot. The old NA K-jet setup is interesting. The 2nd cylinder injection hose was looking pretty busted so I went ahead at replaced it with a braided steel VW/Audi line, like I’d already done with the 1st cylinder hose. The 1st and 2nd intake valve stems also had significantly more carbon deposits than the 3rd and fourth cylinders

Even with the manifold out of the way, soldering under the hood sucks. The engine harness seemed fine less than an inch from the connector box, but I figure effort of adding a little fresh wire was worth it for piece of mind and better access for testing down the road. Installing the new injector o-rings was a piece of cake with new holders and a little Vaseline. Took longer to cut the injectors out of the old holders than it did to pop them back in. I was an idiot for trying to replace just the outer ring on the first injector with all that stuff in the way.

It’s idling better at low RPMs and seems to be running quieter, so I’m going to call it a success overall.

I still have the weird/annoying dimly lit warning lights with a seemingly fine alternator issue, but at least this should help rule out a few things.

Nice car! Very clean manifold.

1) The dimly lit warning lights is usually a failed brush set in the Bosch alternators' voltage regulators. That means it's running probably entirely on battery power :( I would look into it quickly. It stranded me once.

2) If you want to remove visible deposits like that and don't have the time and knowhow to do it, you might do the "chinese water torture" and seafoam treatment. I used it on two cars - my 84 244 with noticeable improvement and soot coming out the tailpipe, and my 90 744 with absolutely no noticeable results.

Might be worth a shot. And Good on ya for replacing the fuel line. I would suggest replacing them all if some of them are visibly failed. It's hard to know what you can't see.

Good Luck!

In my opinion, replace the heater hoses while the intake is already off --- leaking or not! That is, if it hasn't already been done recently. Just my two cents worth!

randyB

With all due respect to Goatman, I would leave well enough alone regarding the head removal to get rid of valve deposits. Yours look quite routine for a high mileage engine - I've seen far worse.

Perform a compression test; if the results show all cylinders fairly close (I'd say within 20psi on an old engine like this), you are going to get very little benefit from the effort and expense of removing/replacing the head and having a valve job done. Valve deposits can cause some idling funkiness, and perhaps a tiny impairment of fuel economy, but not worth a big operation to fix.

Some years ago my Volvo dealer tried to interest me in a valve deposit removal process which involved removing the manifold and blasting the intake valves with a mixture of ground-up walnut shells and high pressure air. Maybe this is still available? Anyway, I declined, as it wasn't cheap and the engine was running fine. 100k+ mi later it still is.
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Bob: son's 81-GL, dtr's '94-940, my 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

Esquire Brontes,


I would go ahead and continue by removing the cylinder head and doing a valve job. That is the only way you will be able to clean those heavy deposits from the valves.


Goatman

Blast. Seeing as how I lack the time, resources and skills required to actually do a valve job, I suppose I'll just have to wait until my head gasket gives out to take care of all that. Plus I wouldn't mind picking up a better cam to throw in there while I'm at it. Hopefully nothing starts to stick between now and then.

I think pulling the manifold has been by far my biggest mechanical achievement to date. It's been a lot of fun so far, but I still have to put it all back together. I should probably pick my battles for now.

Thanks though. I guess that changes my long-term priority list a bit.

With the Intake off, I'd clean the Oil Separator Box.
The heater hose nipples are an obstruction so doing the Separator with the Intake off is just easier.
Take a look at the Heater hoses too. Very easy to replace with the Intake off.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

Check the tightness of the manifold nuts after a few hundred miles.
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Bob: son's 81-GL, dtr's '94-940, my 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

Good to know -- thanks. I've been debating whether or not to use a light grade thread locker on the studs. But I think I'd rather just check them in a few hundred miles instead of dealing with stuck nuts next time around.

Thanks Tony,

The car has the early style valve cover with the PVC up front, so I don't think I have an actual oil separator. The heater hose is was looped back around to the block by the previous owner -- I'm guessing the core leaked -- but thanks for reminding me to tighten those hose clamps. I'm sure they need it.