PDA

View Full Version : Help pinging after timing belt change



Mozn
10-19-2013, 10:30 AM
I decided to change my timing belt, cam, crank, and oil pump seals, tensioner pulley on my 87 accord carb hatch. I put the crank to top dead center by lining up the white mark with the needle on the flywheel, I also marked the old belt, cam sprocket, crank sprocket with a paint pen, then marked the new belt. While I was installing the new belt I noticed that the cam was one tooth off retarded. So I corrected that by lining up the marks on the cam sprocket with the valve cover, and the word up, in the up position. I noticed the old belt was a Napa belt, so I figured the last person to change the belt messed up and did not align the cam properly. Now everything is aligned how it should be according to the Honda maintenance Manuel. Ignition timing is set using a timing light, white mark with vacuum advanced unplugged. No red mark is visible after plugging vacuum back in, but it never has been I believe the red mark is worn off.

Now my engine is pinging/pre ignition very bad while under any load, or during acceleration. The only thing I can think of is the cam sprocket was actually marked incorrectly from the factory, or there was head work done on the engine at some point and the cam sprocket was intentionally retarded one tooth.
I have attempted to retard the timing with the distributor, but no luck.

So question is, what do I do? I'm i missing something, could there be anything else wrong? Should I move the cam back to how I found it?

Thanks help will be greatly appreciated!

Oldblueaccord
10-19-2013, 11:14 AM
Im not up on carb models but check that your not looking for a T on the flywheel for tdc. I think you are on the corect path. I am in the minority that its pretty easy to,get the cam off a tooth.

2oodoor
10-19-2013, 03:10 PM
All those painted marks on the flywheel..none are tdc. Only the faintly scribed sideways T mark. The other marks are fore the timing light and the vacuum advance timing check.

Mozn
10-19-2013, 04:33 PM
From what the Honda shop manual and the Chilton manual says the TDC mark is painted white.

Mozn
10-19-2013, 04:35 PM
Of course I will still go out and check to see if I can find the T.
Thanks for your Help

Dr_Snooz
10-19-2013, 07:55 PM
Spend some time looking over that flywheel to learn the markings. It took me a long time on my car to figure out that there was a "T", a red dot, some kind of green dot and finally the timing mark which was a very faint "1|5". To make matters worse, aftermarket flywheel providers don't follow factory marking conventions. Hell, my new flywheel didn't have any markings at all. I had to engrave them on after lining it up with the old flywheel. The only other possibility I can think of is that the crank slipped while you were putting on the new belt. If you haven't already, check to make sure that the cam and flywheel are both pointing to TDC at the same time. I always check TDC both before and after I install the belt.

Let us know what you end up doing.

Oldblueaccord
10-20-2013, 05:47 AM
http://img17.imageshack.us/img17/9770/z0t6.jpg (http://imageshack.us/photo/my-images/17/z0t6.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

1988 lxi 5 speed flywheel

Mozn
10-20-2013, 10:00 AM
That's what my flywheel looks like. I think maybe the white mark is a T, but one thing I'm noticing now is that Chilton's timing procedure is completely different than what is in Honda's shop manual. I've never been able to see the red mark, but now that i know it's the same as 1|5 I can re-mark it red. If I'm reading it right Honda says to line up the timing light with the red mark and adjust 15 degrees btdc. And chiton says to line up with white and then it should go to red after plugging in vacuum advance. Maybe that ends up being the same thing? I suppose the red mark is 15 btdc hence the 15 scribed next to it. I'm thinking that what has happen is that as I tighten the belt the cam moves about one tooth, which gives me the illusion that it's one tooth off. I'm going to line up the crank to tdc and double check the cam, and I'll be sure to let everyone no what I did wrong or what the final outcome is. Thanks guys!

Mozn
10-20-2013, 11:08 AM
Ok after closer inspection, someone painted the red mark white. I had my wife rotate the crank in the direction the red mark should have been but nothing. Then I had her rotate it the other direction passing the white mark (the one that should be red) and there it was a white t.

Dr_Snooz
10-20-2013, 06:53 PM
The timing procedure of these cars is fairly involved. The express version is to set the timing to 15 degrees BTDC with your timing light. I wouldn't go by colors on the flywheel so much. They can get worn off or changed by well-intentioned previous owners. Glad you're getting closer to a resolution.

Mozn
10-20-2013, 09:43 PM
I think I have everything figured out. I am almost positive that the cam and crank where not aligned properly before I started this venture, as I never really could make out any timing marks. Now I can make out all the marks when adjusting ignition timing. I aligned the crank on the white t, the cam with the horizontal marks to the valve cover with the word up. Adjusted ignition timing via the procedure in the Chilton Manual, and car is running great with one exception, there is throttle hesitation when the engine is below normal operating temp. I'm almost certain this is because I live in Reno and I need to advance the timing a little due to the altitude. Also my vacuum advance seems to be a little weak.

So I think this situation is resolved. I'm sure I would have figured this out on my own, but you guys made it much easier for me and I greatly appreciate your help.

Dr_Snooz
10-21-2013, 06:38 PM
I might not be reading your post correctly, but if you disconnected the vacuum lines and set the timing to "T", then it's out of time. You only disconnect the vac lines to set base timing. Base timing should be 4 deg. BTDC, which is one of the colored dots on the flywheel, not the "T". The easiest way is just set the timing to 15 deg. BTDC (the "1|5" mark on the flywheel). Leave the vacuum lines connected when you set it. If you're worried about your advance diaphragm and want to check it, then do the full timing procedure in the manual on pages 24-2 through 24-8. Basically, without vacuum advance, timing will be 4 deg. With advance, it will be 15 deg. Technically, you should be able to set it to one mark and then it will move to the other mark when you change the vacuum to the advance diaphragm. Most of these distributors are getting tired though, so that rarely happens.

Mozn
10-22-2013, 10:34 AM
Funny thing is that my engine is stamped A20A1 the procedures in the manual doesn't list A20A1. The flywheel on my car actually does not appear to have the 4 degree mark it also does not have the 15 degree mark but has the 24 degree mark. I know I said earlier that it had the 15 mark but I was mistaken. Also on my hood it says timing should be 24 +-2 btdc, but hood is not the original but was taken off a car identical to mine even the same color, but 1 year older 1986. If I knew the diameter of the flywheel I could calculate 4 btdc. I'm sure I could find out the diameter with a google search. I also I'm starting to realize that The Chilton manual is lacking in A lot of ways I actually had to take everything apart at one point because Chilton fails to mention that the timing belt guides need to be installed ] [. It simply says don't forget to install them. Chiton also says align timing to the white mark tdc with vac advanced unplugged. I just figured I would go ahead and try that but when I plug in vacuum advance it doesn't match up with 24 degrees. So I think I will stick with the honda manual. But one thing I have noticed what could be a issue is that the vacuum line going to the advance is not within specs I'm getting 15 hg and it should be 20 hg. I'm not seeing any leaks and engine idles very smooth. So I'm not understanding why the vacuum is low.

Mozn
10-22-2013, 10:40 AM
Also idle is within parameters and engine is warmed up. I think I will go ahead and leave vacuum advance plugged in and set the timing to 24 degrees like you said, if I can not get the procedures to work via the Honda manual.

Dr_Snooz
10-27-2013, 07:59 PM
Funny thing is that my engine is stamped A20A1 the procedures in the manual doesn't list A20A1. The flywheel on my car actually does not appear to have the 4 degree mark it also does not have the 15 degree mark but has the 24 degree mark.

The timing values do change depending on the type of engine and local smog laws. If yours says 24, then set it to that and forget it.

The Honda manual is about the best factory manual you will ever find. Chilton has nothing to add and as you've found, can be confusing and inaccurate. For your next repair, just leave the Chilton on the shelf.

Is the car running properly now?

Mozn
10-27-2013, 09:03 PM
Well it's almost properly running, i checked for vacuum leaks by blowing smoke into a vacuum line, found 3 leaks and fixed them, I adjusted idle both with a/c and with out so every thing is at 800 rpm. Turned a/c off, timed the ignition 25 btdc still hesitated from a stop, and surged during acceleration. So then I repeated the process with idle just to make sure it was set, then I advanced even more not sure how much I'd say 30 to 32 btdc gradually with test drives. Ran great all day, no surging and no hesitation, with more acceleration then my car has ever had. Today it started up right away no hesitation from a stop, but now it is surging again during hard acceleration around 2500 rpm and idle has dropped to about 400 with a/c off but still good with a/c on. I have checked to make sure that the clutch cable is not interfering with throttle cable, throttle cable is not pulling on accelerator portion of carb or too loose. I do need to check vacuum pressure again now that I have fixed any leaks, but other than that only thing I can think to do is advance the timing more. Also there is no pre ignition and timing belt is installed correctly. In addition I adjusted valve lash with the engine cold, and replaced valve cover gaskets and grommets. I suppose the timing advance could still not be working properly.
Sorry for the long posts, I figure the more info I can give the better.
Thanks

Mozn
10-27-2013, 09:10 PM
I should also point out that around 3500 to 4000 rpm there is a significant increase in power/acceleration guess that makes sense as I think that is within the max horsepower a screaming 98hp 115 ft lbs TQ range, but my car has never kicked like that before.