Valve Adjustments with Go-NoGo feeler gauges

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I recently did a valve adjustment for my 1999 Honda Accord V6 that is currently north of 250K miles. This was my first time doing a valve adjustment and it is sure not forgiving... Now I'm left with a P0171 code and pending code P0170. I also cleaned the EGR valve, rebuild the PS pump, changed the valve cover gaskets, spark plug tube gaskets, etc mostly gasket/oring replacement for the manifold.

When adjusting the valves, I used the Go-Nogo gauge. I'm pretty confident I've done it correctly (tried it twice) but I'm here in attempt to find the proper way to adjust the valves.

My question is: Do I use any type of pressure when checking to see if the "NoGo" part will fit?


The car was running fine before so I can only ascertain that the code is due to the valve adjustment and not the fuel regulator/air leak as some may suggest. However, this car does experience sporadic idling issues when starting from a "hot start" where i have to give it gas for it not to stall out. It doesn't happen often but it does, mostly in the summer.

Background

Currently specs off the service manual are -
intake - .20-.24mm
exhaust - .28-.32mm

Intake
I used the .203 - .254 feeler to adjust this one. The .203 part is able to move around freely with barely any friction while the .254 part does not fit at all, even with moderate pressure. In theory the clearance should fall the upper and lower limits of the feeler gauge - approx .2285?

Exhaust
I used the .279 - .330 feeler. The .279 goes in freely with no friction however the .330 is able to fit between the lashes with moderate pressure. I think this is fine as I read the exhaust valve will get tighter over time (which it did when I was adjusting it.) However, if I checked the valves with very light pressure, it will not go in. I was not able to make it where .279 goes in freely and .330 does not fit like the intakes. With every attempt, it is either .279 goes in freely and .330 goes in with moderate pressure OR .279 has a lot of friction and .330 does not fit.
 
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That is great to hear! Maybe the check engine light coming on after my valve adjustment was just a coincidence? Anywho I'm looking into making a smoke machine so I can introduce it to the EVAP system to check for any leaks. The rubber gaskets I replaced were not no longer pliable so I will be certainly shock if there was a leak with these OEM gaskets.
 
Originally Posted By: dorkiedoode
That is great to hear! Maybe the check engine light coming on after my valve adjustment was just a coincidence?


Oh that's funny.

I'm going to call Dorothy and tell her the tornado had nothing to do with her dream!
 
There are other tricks (apart from smoke machines) for vacuum leaks but I didn't have much luck with them and would guess a smoke machine would be the most effective.

The other tricks I recall:-

(a) Blowing butane/propane from an (unlit...er...naturally) blowtorch around the tubing with the engine running. If a leak sucks in combustible gases the idle is supposed to rise.

Didn't work for me, though at least I didn't set the car on fire.

(b) As above with liquid fuel e.g. carb cleaner. I didn't try that. Seemed too risky.

(c) Vacuum pump and gauge, testing to see if sections will hold a vacuum. I used an enema syringe as a vacuum pump, which can also double as a simple gauge by how far the piston returns after holding negative pressure for a while.

This found a couple of leaks, but others remained elusive and I eventually blanked off all the emissions gizmo's (which I didn't and don't understand) with sections of chopstick, restoring drivability. Havn't so far had a reason to re-connect them.

Mileage seems to have dropped from about 17.5km/l to around 15.5km/l, but I cleaned the carb at the same time and I think dirt may have been compensating for a damaged idle jet needle.
 
Before I replace the valve cover, I re- check the valve lash. I know me. Sounds like the go/no go is an improvement over my set, left over from my bug era. You also replaced, cleaned and removed stuff that could create a vacuum leak. My guess is that there is an overlooked vacuum line not hooked up. My father kept bees. Bees get very docile when they get smoked. The smoke is a cotton rag in a can with a spout on it. It also has a little bellows to pump the smoke out. Check out every where you worked. My
 
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We use go/no-go feelers here at work for adjusting valves. Makes it faster. You want just a very slight drag on the go part, and the no-go should not go in. Of course, it can always go in if you push them hard enough.

But your "lean condition" is most likely a vacuum leak from something not connected. Probably one of the vacuum lines at the back of the intake manifold.
 
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Originally Posted By: mightymousetech
But your "lean condition" is most likely a vacuum leak from something not connected. Probably one of the vacuum lines at the back of the intake manifold.


I gave it a go to re-check the vacuum lines for the fifth time and I am pretty sure it is not a vacuum leak, at least a visible one. Hopefully the smoke machine will be able to determine that this weekend.
cry.gif


Upon further research, isn't a lean condition, if linked to the valves, attributed to valves being too tight? If I adjusted the valves to where the minimum clearance is freely moving without drag, this cause my issue.

Based on Honda Service Manual, i should be checking
Fuel Pressure > Primary O2 Sensor > EVAP Canister Purge valve > Valve Clearance > Fuel Injectors.
 
Wow I've never seen anything like this before. I reset the ECU and after driving 25 miles the check engine light came up with the same code P0171 & pending P0170 - long term fuel trim peaked at 18.75. After driving another 25 miles I started to notice that my long term fuel trim was slowly going down until it reached 0...

My check engine light is no longer on! (I didn't touch anything beside removing the negative cable to reset the ECU). I'm going to keep on eye on this because when I reached my destination the LTF stopped at -0.78. Seems like the car is trying to go rich now?
confused.gif
 
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Ok it looks like it is normal behavior for LTFT to fluctuate between +/- 3%. I believe the car is trying to compensate for the lean and rich conditions. Ultimately, I do see that this value balanced at 0% (or near it) at the end of the drive.

I think the issue resolved itself...
laugh.gif
 
Originally Posted By: dorkiedoode
I recently did a valve adjustment for my 1999 Honda Accord V6 that is currently north of 250K miles. This was my first time doing a valve adjustment and it is sure not forgiving... Now I'm left with a P0171 code and pending code P0170. I also cleaned the EGR valve, rebuild the PS pump, changed the valve cover gaskets, spark plug tube gaskets, etc mostly gasket/oring replacement for the manifold.

When adjusting the valves, I used the Go-Nogo gauge. I'm pretty confident I've done it correctly (tried it twice) but I'm here in attempt to find the proper way to adjust the valves.

My question is: Do I use any type of pressure when checking to see if the "NoGo" part will fit? If you want to "feel" what .019 feels like(or any leaf in a feeler gauge set), use a click type micrometer to measure the thickness. That is what .019 feels like. Using your method, you shouldn't have a problem. That is the way I adjusted Honda valves for all the years I drove Hondas.
smile.gif



The car was running fine before so I can only ascertain that the code is due to the valve adjustment and not the fuel regulator/air leak as some may suggest. However, this car does experience sporadic idling issues when starting from a "hot start" where i have to give it gas for it not to stall out. It doesn't happen often but it does, mostly in the summer.

Background

Currently specs off the service manual are -
intake - .20-.24mm
exhaust - .28-.32mm

Intake
I used the .203 - .254 feeler to adjust this one. The .203 part is able to move around freely with barely any friction while the .254 part does not fit at all, even with moderate pressure. In theory the clearance should fall the upper and lower limits of the feeler gauge - approx .2285?

Exhaust
I used the .279 - .330 feeler. The .279 goes in freely with no friction however the .330 is able to fit between the lashes with moderate pressure. I think this is fine as I read the exhaust valve will get tighter over time (which it did when I was adjusting it.) However, if I checked the valves with very light pressure, it will not go in. I was not able to make it where .279 goes in freely and .330 does not fit like the intakes. With every attempt, it is either .279 goes in freely and .330 goes in with moderate pressure OR .279 has a lot of friction and .330 does not fit.
 
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