Has anyone replaced CIS Airbox themselves?

[tim.gelling@eur]

Yep! blew mine up this morning. Has anyone done this job themselves? Looking for tips on whats required and if I need to drop the engine to do it.

thanks in advance
tim

[john walker's workshop]

the year of the car is helpful when you post. 80-83, you really are better off doing it with the engine out. up to 79, it's not too hard in the car, but lowering the engine makes it a tad easier. account for every nut and washer and check down each intake to be sure nothing went in, and rotate the engine a couple times to check if anything slipped through an open intake valve. install the breather hose to the vent cap before slipping the intake assembly back in if you do it in the car. remove it as a complete assembled unit and reinstall the same way.

[dlagerstrom]

My engine had to come out anyway, so I redid the CIS sytem over the winter.

After dropping the engine, I reomoved the entire CIS. It allowed me to replace some of the potential leakers on the engine.

It turned out my airbox was blown-up as well. I used some marine epoxy to put it back together and installed a pop-off valve. Then, since I'm there, I replaced all of the rubber bits, vacuum hose, fuel lines, intake manifold boots, etc. I even took the opportunity to send out the injectors for a good clean/check. It isn't hard with everything out, I don't know but I think it would be tough with the engine in the car. Kinda depends on how long you are willing to have the car off the road.

As I mentioned, my box was broken and I didn't know it. I drove it for a few months that way. Never had a back-fire so I think it was broken when I bought it. It ran great but my fuel mileage sucked. Like 15 mpg. I think the PO just had it running really rich to make up for the unmetered air.

Welcome to the board by the way. I see you are fairly new. Do we have pics of your car yet? What year/model are we talking about?

[tim.gelling@eur]

oops! sorry about the oversight, the car is an 81 targa steel widebody hopefully the picture post, this is the car when I first got it, the changes and work I have done so far are:
new turbo tie rods
new bilstiens
alignment, corner balance
tune-up
starter
rebuilt front calipers, new pads all around, flushed and bled
front triangulated strut brace
harness bar and harnesses
new sport engine/trans mounts
replaced aftermarket wheels with original fuchs 7/9
replaced aftermarket tea tray with duck tail
replaced cheapo seats with leather recaros
replaced white face gauges with black

I have run the car at pocono south, watkins glen and lime rock once each and it has run and handled great, so far lots of fun.
thanks for the info, I think this will go to the shop in the interest of time and getting it done right. Interesting to hear about bad gas mileage if the box may have had an existing crack or leak as my mileage seemed pretty bad 12-15mpg.

[tcar]

Nice car. Something's wrong, milage is waaaaay low.

[ljowdy]

I just recently purchased a complete 1973.5 CIS system for my car. I was able to remove the old system (intake manifolds and everything above them( and install the complete CIS with the engine still mounted. Best guess is the whole job took about 3 hours.

I guess you'll be installing a pop off valve during your air box replacement, won't you???

[safe]

I changed mine last year with the engine in place. When I re-installed it I lowered the engine in the rear 2 inches (search for partial engine drop) to make it a bit easier.

+1 on what JW said about being very careful about every nut and bolt. Slow and easy is the key.

It can be done in 1 day, maybe a weekend if you take your time and clean things and replace "hard to get at" parts, like breather hose and gaskets.

A life saver to have is a 1/4" wrench with sockets (12 and 13 mm ) and extensions. Otherwise it can be hard to reach the intake manifold nuts.

EDIT:
When you have the CIS on the bench inspect every part and make sure they function properly.
Replace all vacuum hoses and gaskets.