1987 Honda CRX HF 1.5 HELP

[mrbillhf]

I've made big strides and it has been totally fuel mixture related. All of my headache has come from a bad fuel filter, dirty carburetor, and vacuum leaks. It's 90% better. Still seems lean. Has a bit of a hesitation during slow speed acceleration. The accel pump is working but immediately after the "squirt" is when the "blubbering/stuttering" happens. If I open up the throttle more it richens up and smooths out. Must still have crud in there somewhere. IMO

[mrbillhf]

I'm writing now to bring closure to this issue. I'm certain my symptoms have been experienced by many. I was almost to the point of buying/replacing control units and ecu when I was encouraged by a tech named Eddie at National Carburetor in Florida. He felt strongly that my symptoms merited another look at the carb. I now drive a very smooth running CRX HF. My low end torque is amazing. The car accelerates out of corners from 1100rpm with smooth torquey acceleration. The popping miss at idle is gone. The chug-a-chug-a felt at hwy cruising speed is gone. I am so pleased.
If anyone else travels this path I encourage you to clean the carb to perfection. [I did it 4 times] My last effort involved running only one small strand of a #12ga wire through a clogged vent in the carb top. So even after removing all jets, blowing thru them and the fuel ports within the carb main housing, there was the smallest pin hole vent that was blocked and it created a lean condition throughout the rpm range that gave me poor driveability.
My next move is to install an original 49 state HF transaxle back in it to get the proper final drive ratio back in the car. I was worried before that the engine wouldn't be able to pull the higher gear. I feel good about it now.
So don't assume anything with that Keihin. clean - clean - clean - confirm

[GasSavers_Erik]

This is very good to know- especially if someone is contemplating replacing that uber rare extra tiny 5 wire oxygen sensor.

[mrbillhf]

Pics show the little vent that was causing my lean condition over the range from idle - 3000rpm. I don't know the theory behind it, but I know it was my final cure. Remember, all jets needed to be clean not just this vent. But it was this pin hole that was the icing on the cake for my cure. Love my car!

[mrbillhf]

Originally Posted by mrbillhf

Pics show the little vent that was causing my lean condition over the range from idle - 3000rpm. I don't know the theory behind it, but I know it was my final cure. Remember, all jets needed to be clean not just this vent. But it was this pin hole that was the icing on the cake for my cure. Love my car!

ps. This is just a spare carb... the one I'm running is cleean.

[kamesama980]

I know from experience on bikes, if the carbs aren't clean enough to eat off of (well, other than the gasoline), don't bother with anything else.

[mrbillhf]

I know it's a year old thread. I just wanted to document my experience for other 1st Gen carbureted CRX HF owners. I'm trying to keep another one from being "de-vac'd" and destroyed. So... Just this month my 87 CRX HF began that dreaded lean condition again creating horrible driveablity issues. Wouldn't idle. Irratic idle. Spit and sputter during light acceleration. Chuga - chuga at cruising speed. I put up with it for a week while it slowly got worse. The fix? I grabbed a can of carb cleaner with a straw nozzle and blasted that little vent pictured above in this thread. Probably not the best idea because it pushes garbage in instead of out and away but it cured it. That pin-hole sized vent is crucial and surely has taken out alot of these wonderful cars. My next focus needs to be on better sealing of the air filter in the housing. Love my car!
Hope this helps someone.

[ukrkoz]

Thank you. Sure does.

[s-harris@juno.com]

Yeah, it helped me. My 87 HF is nebulous. It will run acceptably for a while and then suddenly run like crud intermittently. Anyway, I blasted that vent hole with carb cleaner last night and it really seems to have gotten things much smoother. In the future, I am hoping if it has one of its intermittent bad moments that I can just clean that vent and bring things back to good. I had been running seafoam in the gas and running premium fuel, but that will only help keep the jets clean, not the vents.

Thanks for the pics and the heads up

[s-harris@juno.com]

So, where does that vent go? My car was running like a turd last night. I was in heavy stop-and-go traffic and had to nurse it until I got home. I shot down the vent with carb cleaner and she's back to good. So now I want to know:

1) What is the vent hole feeding?
2) Why is mine getting dirty so quickly?
3) Can I jam a wire through it to clean it without fear of harming something?
4) What would it do if I tried to open the diameter of the vent? In other words, maybe if it wasn't so small it wouldn't regularly clog up. I don't want to mess with it, though, if it will screw something up.

Does anyone have knowledge on this vent hole, it's design intention, and potential things to make it less of a chronic issue? Any carb diagrams on how/what it does?

Thanks in advance