6 replies to this topic

[sibfox]

Alright ive been wrenching on this 84 crx 1.5 all day today and for the last 3 weekends.. so far we have hammered out many issues.. we are left with just a few and hopefully the combined minds of this forums gear heads can help us

the car does have 180k miles and we believe its on all org. parts

problem 1:
We have been unable to get the car to sit at a steady idle.. usually it jumps anywhere from 800 to 1200 rpm at running temp.. it isnt a bouncing surge but more of a inconsistant idle.. we figured it had something to do with the throttle sticking ever so slightly but even if you push it with your finger to its lowest point it still bounces around
.. getting the moter to sit at about 850 to 900 rpm isnt a problem if the air cleaner housing is off.. but if we put it back on the idle will not go any lower than 1100 rpm even if the timing is dead on and the idle adjustment screw is backed all the way out


problem 2:
Whenever you push on the gas pedal hard we are getting plumes of lovely blue smoke coming from the tailpipe.. if you raise the rpm of the engine slowly you will not get the same results.. only when you give it a good 1/2 to 3/4 push on the gas pedal.. what we are wondering is how do we determin what is causing this.. is it the valve seals.. the piston rings.. what tests can we do to find out what the problem is



http://home.comcast....lo1/CAPTURE.AVI

and just because this MIGHT help and because i know you guys love looking at these cars.. here is a little vid clip of the moter running with a tach and a vacume gauge sitting at the bottom of the cam.. if you have questions for me go ahead and ask ill be sitting here ready to reply

thank ya

[strudel]

Open the IACV and tighten the big plastic screw with a very wide screwdriver. Or take it out first and put some plumbing or gas tape on it and reinstall. Don't lose the o-ring under the plare and then adjust the idle screw. JS

[3gencivic]

something you might wont to cheak is your gasket UNDER the black spacer under the carb. i had that problem and a hard time to start. turnd out the gasket had deteriated and the thin gasket between the carb and black spacer had gotten wrecked. replaced it and i had a new car ideal screw got to get set right again insted of turnd out all the way and the air intake didnt casue a issue after.

[xfurb]

The intermittent idle were is bobbles or loads up to 1500rpm and then drops to 500rpm or so. I found that the Lambda linkage is open too much. (Only on a CVCC engine) It’s best not to adjust this until after everything else is working good. The Honda CRX Shop manual has nothing on the linkage. My manual for my old ass Accord (also CVCC) talked about adjustment and its purpose but nothing on troubleshooting. The Lambda Linkage is the control linkage between the main throttle plate and the Auxiliary throttle plate, it is set at the factory. I found the problem after I tuned the engine the best I could and the damn bobbling idle wouldn’t go away unless I adjusted the idle too high. With the engine running at about stock idle 700 rpm or as close as I can get it I notice a faint sound from the carb, that was reminiscent of a drinking straw at the bottom of grass -slurp. Inquisitive as I am I shined a flash light down the carb, while it was running, and noticed a droplet of fuel forming and then dropping in the semi-closed dime sized throttle plate of the Aux chamber venturi. Every time the droplet dropped the RPM dropped then climbed just after all evidence of it ever being there was gone. Then a new droplet formed and the whole process repeated. -So I turned the mystery screw on the front of the carb closing its throttle just a bit. The droplet stopped forming and the idle smoothed out. I don’t know if this helps at all...

Location: Looking into the engine bay front of the carb right side. The adjustment screw farthest away from the carb body, I think it’s the idle boost for lights/fan. (it’s concealed by the vacuum actuator for the secondary throttle plate) Just to the right of that adjustment screw on the carb body is a Phillips screw by itself, mine had a yellow paint on it. If you need a picture I think I can get for the screw location.

Your vacuum gauge is a good indication for determining valve guide wear and maybe valve guide seal wear. Once the idle is normal connect the vacuum gauge- watch the needle if the needle bounces with the idle +- two or three psi the guides are worn. Compression test can determine the severity of worn rings. You know the drill- pull all the plugs test the cylinders dry and then test them after squirting oil in the plug holes; if there is a big increase then the ring have seen better days. I’ve fixed a valve guide seal without pulling the head by pressurizing the associated cylinder to hold the valve up. PCV valve stuck? I think that’s oil burning all the time though. I hope I didn’t bore you with my poorly written novel.

~dan

[sibfox]

thank you all for your input.. now taking this information i shall create ART!.. or just a smooth running engine, TO THE TOOLBOX

[lxndr]

Problem 2 is typical of bad piston rings, but you should do a compression test to be sure. After you test it, squirt a little oil onto the cylinder and test it again. If you get more PSI after the oil treatment then you've definitely got bad rings. The reason for this is that the oil tempororily seals the rings long enough for you to get another compression reading.

If you had bad valve seals you would find a large cloud of blue smoke on start up, then it would go away as you drive.

[sibfox]

-looks at watch- waiting for a soon to be bitchslapped friend to get here with the compression tester