Timing process questions; timing light questions

[PNW vanwagon]

i've got the exact same van (1989 cargo 73k miles) and the exact same problem: light pinging under load just recently.

i've been swamped with work so i did the same: switched to mid-octane and has 100% fixed problem until i can buy a timing light and adjust timing

it might be a dumb question: but it sounds like you've had trouble finding space to rotate the distributor - were you able to remove the passenger seat and engine cover to gain access to that side of the engine?

i did some research on pinging and a few common reasons:
lean mixture, over advanced timing, carbon deposits in combustion chambers, EGR valve etc

http://www.onestopauto.com/What-causes-spark-knock.html

^ article mentions minor pinging is acceptable - which is the type i have. but i'll still get after adjusting timing as soon as i can. along with an oil change and front brake pad replacement

keep me posted on if you get your's solved - and i'll do the same. i'll be curious to see if slightly retarding timing cures the pinging and allows me to switch back to 87 octane fuel

[rcf_1989]

There is no problem with pulling the right side engine cover (other than perpetually wondering why it wasn't set up like
the left side since most tune up steps require access to that side of the engine).

There is only a very narrow visibility passage for the timing light to see the marks on the engine, so I need to make the
pulley mark as obvious as possible.

The problem was that I could not see the timing mark on the main pulley and could not reach my hand, or a socket, between
the engine and fan from above in order to hand-turn the engine to search for the mark and put a dab of paint on it. I also could not get my
head underneath in a position to even see the pulley from below. I think you'd need jack stands to get enough clearance. (Even so,
no flat ground to work on.)

I'm mainly hoping that someone could describe the particular contortions needed to see the pulley clearly and to rotate it to find the timing
mark. (And a clue about the typical cause for a "lean mixture" error code. Air filter was new not too many miles ago. I am wondering if the timing
being off confused the computer.)

i've got the exact same van (1989 cargo 73k miles) and the exact same problem: light pinging under load just recently.

i've been swamped with work so i did the same: switched to mid-octane and has 100% fixed problem until i can buy a timing light and adjust timing

it might be a dumb question: but it sounds like you've had trouble finding space to rotate the distributor - were you able to remove the passenger seat and engine cover to gain access to that side of the engine?

i did some research on pinging and a few common reasons:
lean mixture, over advanced timing, carbon deposits in combustion chambers, EGR valve etc

http://www.onestopauto.com/What-causes-spark-knock.html

^ article mentions minor pinging is acceptable - which is the type i have. but i'll still get after adjusting timing as soon as i can. along with an oil change and front brake pad replacement

keep me posted on if you get your's solved - and i'll do the same. i'll be curious to see if slightly retarding timing cures the pinging and allows me to switch back to 87 octane fuel

[Rudy]

Bump the starter so the engine rotates a bit. When it stops, can you see the mark on the pulley? If not, bump it again and see where it lands. Eventually, the pulley should stop a location that you can seen the mark.

1.If I remember correctly, a lean mixture coming out the tailpipe is from retarded timing. Google that one.

2.I use regular octane, but I use non-ethanol gas. It is a significant improvement in terms of a smoother running engine and no heat soak issues.

[rcf_1989]

Thanks.

I tried bumping the starter a handful of times and didn't get lucky. I guessed (wrongly I suppose) that it tends to land
in preferential spots. Sounds like doing that more patiently might be the only way.

I am curious to see about the non-ethanol gas. I can try a tank next time. I think that the mid-grade and non-ethanol regular
are not that different in price though.

And, yes, retarded timing and lean running tend to go together. I will double-check the vacuum hoses and air filter. I did test
the primary O2 sensor and it passed.

Bump the starter so the engine rotates a bit. When it stops, can you see the mark on the pulley? If not, bump it again and see where it lands. Eventually, the pulley should stop a location that you can seen the mark.

1.If I remember correctly, a lean mixture coming out the tailpipe is from retarded timing. Google that one.

2.I use regular octane, but I use non-ethanol gas. It is a significant improvement in terms of a smoother running engine and no heat soak issues.

[Rudy]

...or take that plastic guard off below to get a better look
or feel for it with your finger
or try to give one of those extendo mirrors a shot

Just throwing out ideas. Good luck!

[originalkwyjibo]

It is definitely a pain to see the timing mark especially with a timing light. Just a heads up though, some other members here have had issues with the rubber bond between the two halves of the harmonic balancer deteriorating to the point that the outer portion, where the timing mark is located, has moved in relation to the inner portion and the crankshaft. This causes the timing mark to potentially be way off.
Here's a good timing mark visual from Tim's engine rebuild blog:

[rcf_1989]

Thanks.

[djshimon]

It is definitely a contortion but I did use a socket wrench to turn the crank but I can't remember which size it is-pretty big one, maybe a 19mm? I don't think I removed the fan shroud but that would make it easier.
Also I used an orange marker pen to mark the notch on the crank pulley so I can see it when doing the timing.

[rcf_1989]

It is definitely a contortion but I did use a socket wrench to turn the crank but I can't remember which size it is-pretty big one, maybe a 19mm? I don't think I removed the fan shroud but that would make it easier.
Also I used an orange marker pen to mark the notch on the crank pulley so I can see it when doing the timing.

Thanks, I couldn't fit my socket between the pulley and radiator. I wonder if the gap was larger in an older van? Like you, my plan
is to put a paint mark on the pulley. I'll try again this weekend and see if I can make anything fit.

[Ace MM]

switched to mid-octane and has 100% fixed problem until i can buy a timing light and adjust timing
i'll be curious to see if slightly retarding timing cures the pinging and allows me to switch back to 87 octane fuel

In another car, I have this issue.
Retarded timing is likely the cause.
Runs so much better on 91 vs 87 octane

Curious to what plugs your using.
On my car, I recently tried some platinum tips and have less pinging under the same conditions.

[PNW vanwagon]

In another car, I have this issue.
Retarded timing is likely the cause.
Runs so much better on 91 vs 87 octane

Curious to what plugs your using.
On my car, I recently tried some platinum tips and have less pinging under the same conditions.

i used NGK Platinums as they were available from my local parts store.
that was a few months ago i installed new spark plugs, spark plug wires, distributor cap and rotor

it's a very recent occurrence: very slight tapping sound when under load. like a muffled typewriter

just for clarity sake: are you saying i should adjust my timing to be more advanced? i had read pinging can sometimes be solved by going the other way : retarding the timing one or two degrees

thanks for clarifying - it'll be good to know when i get to work on my engine

[rcf_1989]

Hi all,

Thanks for all of the replies to my questions. I had time yesterday to take another look.

Key help was to remove the plastic shroud over the fan. Two bolts at the top on either side.
The bottom of the shroud is removeable to slip it around the fan for both removing and reinstalling.
The clips holding the bottom in place are set up so that you don't have to remove it completely. You can
disconnect it on its top on either side of the upper part of the shroud. The lower clip lets it
pivot just enough to guide gently past the fan blades.

Once the shroud was removed. it was easy to rotate the crank. The timing mark was actually
very clearly marked with a white painted triangle (looked like from the factory). Now that I knew
it was there and what it looked like, I went back to checking the timing.

I think a second key thing that helped yesterday was that it was no where near as bright out
as on the last time. (No garage, I have to work in my driveway.) Even knowing the timing mark
existed, it took a lot of experimentation to light it with the strobe. There seems to be exactly
one viewing position that allows you to see both the engine mark and the timing mark. If the
light rotates even a few degrees, the timing mark disappears. It was pretty ethereal in the daylight.
I bet everything is easier if you can work in a garage or carport.

So, I think it was a combination of not knowing what the timing mark would look like, too much ambient
light and not getting the strobe in exactly the right position that frustrated me before. There was no need
to clean the pulley, so that mark was viewable the last time; I just didn't find it.

After all that, the timing was, as far as I could tell, dead on. It might have been slightly retarded
(11 deg instead of 12 deg). But, that was because it was hard to make sure that I was getting a
nice direct view of the two marks from above. After removing the jumper, the timing shifted to about
18 deg, which as I read the manual, is OK. It just says that it should shift to near 20 deg.

The timing light I borrowed was one that allowed me to adjust the triggering so that I only need to look
at the TDC mark. I think that type would be easier for this vehicle since the engine doesn't even have
a -12 deg mark.

Remaining questions:

1) No pinging at all using the mid-grade gas. Pings on regular.

2) Still getting the "lean mixture" error code. (I did reset it last time.)

3) I pulled the #1 spark plug. Looked good to me, normal wear. NipponDenso P16R. I looked
closely at it and I think that it has platinum discs on both sides of the gap. Since the engine
runs great and since all the plugs are the same age, I didn't bother looking at the other three.

Can anyone come up with a reason why pinging and a lean mixture code would occur? Or, should I
assume that they are separate issues?

I ran the O2 sensor check and it seemed to be functioning as described in the manual. Any reason
to try replacing it?

I didn't see any disconnected vaccuum lines. The hoses looked OK to me.

Thanks again and I hope the above is helpful.

[PNW vanwagon]

^ i researched some on running lean causing pinging. possible causes:
- low fuel coming thru due to clogged fuel injectors or fuel pump
- small air leak in one of the various air hoses
- MAF mass air flow sensor malfunction

i'm wondering if my main air intake tube has some small crack. i replaced my air filter a couple months back and had to disconnect that big main air intake tube. it looked to be in perfect condition but i'll have a closer look while i'm checking my timing. maybe re-tighten the clamps while i'm at it

i'll probably retard my timing a little bit even if my timing seems right on and see if it helps.