persistant cel and drivability issues

[bmwdirtracer]

The secondary air works at cold start only, but that includes temps up to 90 degrees....or you'd never pass inspection in the summer.

Use a mirror on a stick, and look at the vacuum lines at the back of the manifold. These rot out badly. And may I ask how you know the check valve works?

[Dusterbd]

The inline check valve was checked manually last month when i had the intake off to replace every rubber hose, gasket, and oring in the system. All the vacuum hoses behind the manifold are brand new, and definitely not leaking.

I did not test the electric solenoid back there.

The valve on the head holds vacuum. Thats all i know about it.

The pump under the bumper blows forcibly through the hose to the head with no discernible leaks i can find.

[bmwdirtracer]

I'm sorry, Michael, had a rough couple of days at work, and forgot to look for stuff for you. I've made a note to myself, hopefully I'll find some helpful items tomorrow.

[Dusterbd]

No worries!

Im not even sure i actually need anything at this point. Other than time to diagnose the secondary air injection system

[bmwdirtracer]

Well, I've had a hunt around today. I've got a spare secondary air control electrical solenoid I'm happy to give you. I do not have a spare valve that bolts to the head. In my experience, the electric control valve isn't usually the fault; it's usually either the vacuum hoses, or the valve which bolts to the head. (Unless it's a V8, in which case the cylinder head passages are clogged)

When you did the vacuum hoses, were you careful to return them to their original location, and point the one-way valve the right way?

I have the adapter hose for your schrader valve, if you want to borrow that. Not a big hurry getting it back, I have a spare.

Unfortunately, I can only find 5 of 6 black injectors, which will do you little good anyway, even if you're ready to send your injectors out for cleaning. If you're ready to do that, I'll pull a sixth injector from another "parts" motor, and lend you a complete set to use while you have yours cleaned.

Chris

[Dusterbd]

Ill have to look at my dissassemly pictures and compare with how its put together. Im positive that i put it together the same way it came apart, but may have screwed up, or it may not have been right in the first place.

The valve on the head: if i pull it for cleaning, will the gasket be reusable? Or can high temp rtv be used?

Thanks for the solenoid.

Im going to hold off for now on sending the injectors out. Reading the plugs, they are all pretty close to one another so i am confident that we dont have a stuck or clogged injector. (Been a minute since i read plugs. Takes me back to dragstrip tuning carbs)

[bmwdirtracer]

I'll send the control solenoid tomorrow. I'm going to leave the piece of crumbled vacuum hose and 1-way valve on it, so you can see the orientation. The gasket should be okay to reuse. I don't recommend silicone for this. Have you priced a new valve? (I have not)

[Dusterbd]

Thanks so much for this. I really appreciate it.

Putting a vacuum gauge on the line to the valve revealed no vacuum under cold start conditions this morning. So i know theres a problem with that part of the system. Seems a good place to start.

[bmwdirtracer]

It is on the way to you.

[Dusterbd]

Thank you mr powell!

Next time im up tgat way i owe you lunch.

[Dusterbd]

Ok, so im finally back on this.
I cleaned the valve that bolts to the head. It was gummed up and not moving, now it does. However, i broke the plastic tube from the pump to the valve in the process. So ill be stopping by the parts store and getting some adhesive lined heat shrink tubing to repair it. Then, clear codes and sees what happens. After that, well see if the solenoid needa replaced.

[bmwdirtracer]

You don't have to repair the old rotting plastic tube - just replace the whole arrangement with a single piece of good vacuum hose.

[Dusterbd]

It measures right at 1 inch od on the plastic tube. Heater hose be ok?

[bmwdirtracer]

Oh, I'm sorry....I thought you were talking about the vacuum tube to the rear of the manifold. Heat shrink should be okay, except that the rest of that plastic tube is equally brittle, 20 years old. The part will cost you $19 at ECS Tuning:

https://www.ecstuning.com/b-rein-par...721435456~ren/

Heater hose will likely have problem making the bends without kinking, so you'll likely be better off with your original idea of heat shrink.