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Discussion Starter #1
I'm pulling the head off my 89 L-Jetronic Spider; this is the first time I've pulled a head on a Bosch car, though I've done lots of Weber and Spica heads.

Is it customary to separate the intake manifold from the head and leave it in the car, so I don't have to disconnect all the fuel fittings and injector connections? That's what I've heard. And to do so, do I first need to remove the plenum by its four rubber hoses, and its strut underneath? Then get it out of the way to make room for the intake manifold to pull back to clear the head as it comes up?

Thanks for any advice.

Andrew
 

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Andrew,
Can't see how you'd gain anything by trying what you suggest. I had good luck NOT removing intake manifold from the head until the pair was extracted from the car. Most certainly remove the plenum & fuel rail as they are both attached to the confounded (!#$!) support strut. May seem like extra arse pain, but youl'll probably find that some of your rubber pieces/parts are cracked & brittle. Also, any excuse to replace injector seals is good.
 

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Discussion Starter #3
From Russ Neely, sent to me directly:

The worst part of the Bosch spiders is keeping all the wires straight. The injectors are not the big problem as they are normally numbered and they only reach the proper injector. Note that several of the wire ends are color coded, white is coolant, I think, brown is something else, blue is the cold start injector.
The half dozen black ground wires that bolt to the back of the manifold tend to scatter. I tie wrap them together.
Then there are all the hoses. Take a photo. Or better yet buy a second car that you can go look at to get everything right. That is what I did on my first L Jet rebuild on an 82. I had the 84 that would become my race car in the driveway outside.

Yes, remove the intake plenum. Two 15 mm head bolts hold it to the L shaped support from the motor mount. Remove the throttle bell crank from under neath with the linkage. Then remove the L shaped bracket. There is an 8 mm bolt (13 mm head) bolt under the intake manifold.
The fuel rail is not that hard to remove. Eight Allen head bolts hold the four injectors.
I normally leave the intake manifold attached to the head, just as I do with the Spica manifold and the Weber manifold.

The local Alfa mechanic has hard valve seats installed in the L Jet heads. He has had some customers experience the valves sucking into the heads as the valve seats deteriorated and were beat by the closing valves.
 

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I usually pull the exhaust from the head (leave it attached to the front pipe) and pull the head with the intake attached.
 

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Discussion Starter #5
The head she is removed. I did the job Friday and Saturday in about 4 hours. Getting at the two inner upper manifold to head nuts isn't the most fun, but everything came out reasonably well. Sure is a hell of a lot of stuff packed onto the intake side compared to Weber and Spica cars.

The #1 exhaust valve clearly is not seating fully, and I can't tell if it's burned, bent, or otherwise, but I can shine a flashlight in the port and see a fair amount of light leaking along one side of the seat. The #1 intake boot from manifold to plenum had several big cracks in it, so I assume that cylinder was running lean, and hot, and I'm guessing burned that valve over time. Off to Norman Racing today for an evaluation.

Thanks for everyone's help. When I put it back together, I'll (1) get the cam timing right, which is off TDC by about 5 degrees, and (2) get the VVT working, which has the solenoid plunger in backwards. Head gasket looked good though, and head does not looked warped or corroded. Bizarrely, I can't feel any ridge on the cylinders, even though this car has 160K on it. The PO does not recall every getting a rebuild, just valve jobs. She's sending me old paperwork, so we'll see.

Andrew

Andrew
Andrew
 
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