Air Intake System rebuild questions
 

Greetings GasSavers!

Just bought a '92 Civic VX and this forum has had invaluable advice for the myriad issues mine seems to have (all-in-all pretty solid but *quirky*)

Armed with Helms, advice from these archives, and a little luck I will be tearing down the entire air intake system to try and eliminate variables.
This will include:
EGR; EACV, IAVC, throttle body, intake manifold, injectors and whatever else I haven't listed that's related. I will be doing mostly cleaning and reconditioning of the existing parts.

While I feel confident I can do this my questions revolve around my lack of *specific* experience in doing any of this.

Helms points out a plethora of gaskets, o-rings and the like that they say should be replaced when doing this work but...

(the real question ;)
...how many of these parts can actually be re-used (assuming they aren't damaged in the process) AND which will I most likely need based on your collective experiences.

I'd like to arm myself with the right repair parts without spending gobs or having to wait for things to be shipped because I overlooked something.

Hope that's a specific enough question. Let me know if I need to clarify.

Thanks in advance!!

What problems are you experiencing? Gaskets can be reused if they are not damaged. O-rings are likely hard and brittle.

Rebuilding the intake manifold is a pretty straight forward ordeal. It's not expensive to get all new o-rings and gaskets fo the intake manifold, so all new ones are the way to go. Usually you can get an upper engine gasket kit from the parts store which contains al the necessary gaskets.

Thanks to you and TomO.

The problems I'm having are like several of the other threads: 1) Miss under light load-NOT subtle i.e. like a bucking goat 2) fast and fluctuating idle 3) general poor fuel economy

I've only had the car a couple weeks so lots yet to investigate and problem solve but I have found a disconnected TPS, crappy and underinflated tires, bad rear camber, heavy rims, wrong spark plugs, misaligned body panels most of which I've fixed and have led to a *reduction*!!!! in fuel economy (43 to 35) Grrr. I've reset the ECU after engine fixes, and it has a new 5 wire O2 (LAF) sensor.

Next on my list is to check timing belt and compression (But it's CCOLD outside -whimper :P

So, I'm suspecting fuel mixture/distribution issues and want to at least eliminate gunked up parts from the equation before throwing new ones at the problem.

Will be investing in a timing light, vacuum gauge, fuel pressure gauge, compression tester. These are all tools I should have had a long time ago anyway.

So, any words of wisdom are welcome particularly about common problems/things to look out for when doing this kind of work. (Helms manual makes it all look so simple but I'm a realist ;)

Cleaning the IACV (Intake Air Control Valve), decarbonizing the motor and cleaning the EGR system (the whole system) can be done without even buying a new gasket for anything with the exception of getting new metal slugs from Honda to replace the slugs removed during the EGR system cleaning.

Are you still throwing any codes (CEL on)?

{1} Good to know. Because I was looking at nearly $60 in gaskets and o-rings with 1/2 of that going to the injectors alone. All those damned little things add up! Looks like I can lose the intake manifold gasket; map sensor o-ring;EACV filter and o-ring; throttle body gasket and EGR gasket?
Well, maybe keep the EACV filter just for good measure.

Would you recommend then, replacing all the seals/o-rings on the injectors regardless? ($32)

{2} That's the damned thing... no CEL. Checked the ECU (correct unit), CEL Light works (ignition on), jumpered ECU with no CEL. Runs better than it did now that the Throttle Angle sensor was hooked up but took a big hit on fuel economy as a result. Still bucks like a goat.

Next step would be to test the TPS (Throttle Position Sensor)
Sorry I didn't have time to do a nice little write up, but I'm in a hurry to get home so I just grabbed something from H-T.

Idle bounce seems to be caused by a vaccum leak most of the time, or a number of very small vaccum leaks, to fix my idle bounce I've adjusted my idle speed by turning it down, replaced the lower PCV hose gromet were it goes in to the oil seperator under the intake manifold, this was hard to do but with a pair of needle nose vise grips and a long screw driver I got the old shrunken stiff one out, and a new one installed.
I checked my injector o-rings, and they all appeared to be soft and fit snug like they should, but if you find them to be loose, then of course replace them.
you can find other vaccum leaks by useing a hose as a stethscope to lisen to each hose and fitting.
I also stoped using 0w30 oil and went thicker and found the my idle bounce is nearly gone.

That's interesting that you mention that. This has something very lightweight and doesn't smell natural (i.e. synthetic -came this way and is clean so didn't change it.)

Do you think too lightweight might be fooling the pressure sensors? or...?

TomO: No worries and thanks! Will be checking this soon.