skinnyhb

so i'm a complete moron and probably should be banned from tool use. i adjusted my timing the other day and i forgot to tighten the pinch bolt. i drove for about an hour or so on the highway, with pinging galore, but i just thought i had set the timing a little off, so i didn't think anything of it. about 45 minutes or so the check engine light went on. i got home and realized my mistake as, by then, the distributor cap had slid all the way down to the end of its guide on the pinch bolt. i fixed the timing and cleared the code, however, now after driving on the highway for 15 minutes or so, if i let 5th gear drop in RPMs, i get a check engine light for code 52 and 71. I'm not too sure if they are related at this point. The code 52 is for the knock sensor and the 71 is for the EGR.

- could i just have messed something up in the motor, so that pings/knocks a lot?

- can you wear out a knock sensor?

- why does this only come on in low rpms in 5th gear?

- other than the check engine light, the truck runs great, however it does ping on the highway a little depending on grade of gas and timing setup.

- anyone have any ideas other than me never touching a tool again?

thook

Well, I'm not entirely sure, but it seems possible the timing could have gotten off enough for a piston to hit a valve. Run a compression test.

As for the EGR, if a valve did bend, it could be related.

The way the EGR valve works is partly on backpressure under certain load conditions. The vacuum modulator relies on that backpressure to operate thereby allowing vacuum to open the valve. Run an advanced search on EGR with my username. I have a short thread posted with a link on exactly it operates. That will explain that.

As for the KS, I don't know if you can just wear them out like that/get damaged from knock. Doesn't seem like it to me, but I don't know everything and could be entirely wrong...lol!

So, where do you have the timing set at now?

Oh, and check your plugs for damage.

DeathCougar

iTrader: (23)

Having the timing that far off, the engine would have tried to adjust for it. Thus, when you set it back correctly, the ECU didn't think it was correct. Reset the ECU, and try again.

thook

Right.....there's that, too.

zlathim

Dude, I am having a hard time wrapping my brain around this one. Bear with me because I'm a bit slow at times. How does changing ignition timing bend valves?

DeathCougar

iTrader: (23)

Ignition timing cannot do that. Only cam timing can

thook

Well, like I said, I'm not entirely sure. <<<<disclaimer!!!...

But, if the ignition timing is out far enough on a 22re, they are interference engines and the pistons can hit the valves. Driving around with detonation can do damage. I guess it depends on the extent of the conditions, though.

I don't know....I was grabbing at possiblities and that one was off the top of my head...lol! A compression test is simple and free (well, if you have the tool), so I figure it wouldn't hurt. If all's good, then he could move on. If he found a problem...even if not related to the current issue...the bright side is it could be taken care of. However, he did say it was running good otherwise, so it's probably just fine.

thook

Oh really? Hmmm....well, I guess I oughtta take my self proclaimed expert diploma off the wall...lol!

JUST KIDDING!!!

Seriously, though, I thought it could. Still, how does the ignition timing relate to detonation damage and what all damage can that do? I can be a bit slow, too...

InternetRoadkill

Ignition timing can't cause the piston to hit the valves. Period.

The knock sensor isn't going to wear out because of knocking. You'll burn a hole thru the piston long before you kill the knock sensor.

thook

My bad........I know. But, could anyone e'splain more about detonation? I suppose I could just google it.

zlathim

thook- I think you just confused ignition timing with valve timing...momentarily.

I'm sure everything is back to normal now, but what do I know? I missed the disclaimer completely!

thook

No zlathim...I didn't. I'm just confused in general. Atleast, today I am. Didn't sleep well, so I'm pushing through the fog that was once a brain...hehe.

DeathCougar

iTrader: (23)

Ignition timing causes the engine to fire before, on, or after TDC in the engine. If you have the engine firing too soon, you cause detonation ie Pinging. Its firing before the piston gets back to TDC. Engines run best at stock timing (ie 5 degrees BTDC) but will make the most power somewhere near 10-12 degrees BTDC.

zlathim

OK, today you get a free pass. I have young kids, so I know all about sleep deprivation!

DeathCougar

iTrader: (23)

I feel the pain....except I don't have children, I have race cars

skinnyhb

Alright, i have reset my timing to 5* while the check connector is jumped and reset the ECU. however, the light came back on again while on the highway in low RPMs in 5th gear. i'll make sure im still getting the code 52, but i'm fairly sure i am because there is still a decent amount of pinging. i'm running 89 in this tank. i think i might just need to replace my knock sensor or wire.

thook

And, fortunately that's easy enough on the 22re. Heaven help you if you had the 3.0.....

skinnyhb

i just unplug it and unbolt it from the engine housing through the passenger fender well correct?

abecedarian

Well, I hope that the detonation and heat didn't burn up some valves....

InternetRoadkill

Are you sure your EGR is working properly? It can cause engine ping.