shiv

Hey everyone, ran into a strange issue. Car is is AP1 with approx 40K on the motor. It is predominantly a track car with occasional street use. About a month ago I would get an occasional CEL for misfire on cylinder 1, but never a blinking CEL until last week. So I thought I would freshen up the motor. I adjusted the valve lash and found all the exhaust valves clearanced too tight, and all the intake valves clearanced too loose. I also installed NGK iridium plugs, Denso OEM coils, and new oem injectors. Now when the car fires up it shakes and vibrates even more so with a very lumpy idle. When throttle is applied it struggles to rev up, and it sounds almost tractor-like and a blinking cel comes on almost immediately at which point I shut it down. I have ensured that all spark and injector plugs are fastened securely, TDC 1 and 2 are also plugged in, and there is sufficient fuel in the tank. Thus far I have ruled out the coils by putting in the old ones and netting the same result. I am going to check the injectors against the old ones tomorrow. Does anyone have any further thoughts I should check? When the valve cover was removed I did not notice anything out of place or to be damaged. Thanks much

MorngWoodStewie

Maybe your lash job was no good, thats pretty much the only thing leading back to what you have done; from what is different from when it was just mis firing... swapping oem coils back on was an easy thoughful trouble shoot, Thanks! ... soo that rules them out soo the only thing else was your valve lash job that has changed from mis to what the hell?

shiv

I thought the same and will be rechecking tomorrow. The thing is it was so out of spec when I started, intake side was so loose I could fit the 0.014 Inch feeler gauge without any drag whatsoever, and the exhaust side was so tight that I couldn't even get the 0.008 Inch feeler gauge in at all. So very extreme clearance issues on both sides of the engine. Even after I had torqued them down I double checked to ensure proper clearance on both intake and exhaust side. Outside of valve lash clearance, the only thing left that could be the culprit is on the fuel side. Unless, the engine has been damaged from running such an extreme clearance for so long.

MorngWoodStewie

Hmmm did u try throwing the old injectors back in?

Where did u get the inj from? Possibly wrong part/part# kinda sounds like wrong tune for injectors maybe something stupid like that. I'm hard pressed to think that engine would be in to much despair at 40k.

Edit: sorry just read your gonna try old inj. Again, try that and update. GL

Verify proper clearance. And make sure your doing each one at the right time. I'm sure u kno but u only adjust each cylinder when it's at TDC

I also don't kno if it's possible but I once plugged my TPS into map, and map into tps and it had similar symptoms lol.

What's TDC 1 and 2?

freq

No mention of checking the retainers for cracks.......

Slowcrash_101

Retainers won't cause a misfire though, they'll just destroy the engine when it drops a valve in the cylinder bore. I'm guessing torched exhaust valves, it doesn't take long for overly tight valves to torch themselves and lose compression, then the seals go and the guides start getting wider, then it's bent valves. Honda says that valve adjustment should be done in 10 years or 100,000 miles, I think that's too long. I think you should check valve lash the moment you even suspect there's a hint of misfire. If you hear little random puffs from the motor, check it.

9KEVERYDAY

With the way you describe your tolerances, it sounds like you did not have the cylinders at TDC when adjusting your valves.

https://robrobinette.com/S2000ValveAdjust.htm

Car Analogy

This. It would be really odd to have both very tight exhaust and crazy loose intake. Since that is so odd, and since engine barely runs after you did the adjustment, that seems the obvious issue.

Here is a trick you can use. When you are adjusting the valves, if the cam lobe you are about to adjust is not pointing directly away from the rocker, you messed up somewhere trying to follow the process of aligning timing marks. Do over.

In fact, the way I do it, learned decades ago adjusting virtually identical Honda Motorcycle valves, is ignore the timing marks altogether. Simply turn motor until the valve you want to adjust has its cam lobe pointing away from rocker, then adjust it. You don't even have to be super precise about it. Closed is closed. The whole portion of cam rotation with valve closed is the same.

I find this way not only much faster, but also error proof.

You must always, MUST make certain the valve you are adjusting is not anwhere near being opened by its cam lobe. This is true no matter what method you use.

shiv

I actually followed Rob's procedure exactly. Started at cylinder 1 and lined up the TDC markings on the cams, and checked that the lobes at approximately 11 and 2. After that I would rotate the crank clockwise, while watching the indicators on the cams and stop when they had rotated 90 degrees then adjusted cylinder 3. Then repeated for cylinder 4 and then 2 in that order. One thing that struck me as odd, is that before the adjustment the exhaust smelled incredible rich, like someone dumped 5 gallons of gas on you while in the driver seat. However now there is no rich smell whatsoever. Will be checking injectors and valves once again.

9KEVERYDAY

FIREWALL
4
3
2
1

Did you adjust with the cylinders labelled like above?