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Timing belt troubles

Posted: April 20th, 2010, 3:02 pm
by OkieOFT
So my water pump weep hole was leaking, so I installed a new one along with a new Gatorback timing belt. I get it all back together, thinking I had the belt on perfect, start it up, thing has no power at all. Tear it back down, it's a tooth or two off. I've tried about 8 times now to install this thing right, each time it starts but barely runs. I haven't been putting it all back together, just the belt, valve cover and the main pulley. Without the alternator, PS pump and compressor it starts, jumps up to about 2000 RPMS and drops real quick almost stalling.

How the heck do I get this belt installed right? Each time it comes up a tooth or two off. This is my first timing belt so it's new ground for me, i'm more versed in Chevy V8 repair myself.

Re: Timing belt troubles

Posted: April 20th, 2010, 3:04 pm
by OkieOFT
Is there no edit option here?

Car is a 94 4cylinder DOHC.

Re: Timing belt troubles

Posted: April 20th, 2010, 4:20 pm
by Ryan
edit option is on the bottom left corner of your post.

http://www.mx-3.com/manuals/showimg.php ... B1-012.gif" onclick="window.open(this.href);return false;

start on that page.

Re: Timing belt troubles

Posted: April 20th, 2010, 7:40 pm
by OkieOFT
Been there, done that. Just can't get the belt on there right. Any tips or tricks to it?

Re: Timing belt troubles

Posted: April 20th, 2010, 8:05 pm
by Ryan
No? Thats the freakin' shop manual.

Turn it over by hand to verify before you put it all together.

Insanity is doing the exact same thing over and over expecting a different result, so switch up your technique a little.

What I would do:

- line up crank pulley, and put belt on. Wedge something between the oil pump housing and belt to pinch it in place.
-run it tight up to the exhaust pulley and around and over intake. Verify the belt is tight in all the places, the marks are on, and then engage the tensioner.
-Use a pipe wrench or vicegrip to hold the cams on the hexigonal part to hold them still.
spin the crank with a big ratchet (plugs out) a few times, untill the cams realign.

redo if needed.

Re: Timing belt troubles

Posted: April 21st, 2010, 10:57 pm
by OkieOFT
So I got it on there today. Everything lined up perfectly, right where they're supposed to be. Only problem now is my idle SUCKS! Give it some gas and it runs like a champ, once it idles down it barely runs. Any suggestions? I guess I could take a video of it running if it would help diagnose it.

Re: Timing belt troubles

Posted: April 21st, 2010, 11:02 pm
by Ryan
continue to tune it up....


set the timing/idle...

Re: Timing belt troubles

Posted: April 22nd, 2010, 1:02 pm
by andrewlcraft
Just did this last weekend. I fought setting up the timing marks for what felt like forever, and then it all just lined up and went together perfect. What helped me was getting something to clamp the belt in place on the exhaust cam gear before trying to get the intake lined up and the belt around that and the tensioner.

If it's just your idle that has a problem now and it was fine before, go over everything you took apart to do the job. It's hard for anyone else to say what could be wrong, but if it was ok before, than it has to be something related to what you just did.

Re: Timing belt troubles

Posted: April 22nd, 2010, 10:47 pm
by OkieOFT
So I think I figured out what it is, on the left side of the motor there is what the shop manual calls a "vaccum chamber". It has a vaccum hose running from the intake. Mine has a tee in it that is connected to a vaccum hose that runs to the firewall. The shop manual shows no tee. Before I replaced the timing belt the hose to the firewall wasn't connected, the tee it had in it before was broke. While I was doing the timing belt I replaced the tee and connected the firewall hose.

When I pull the firewall hose from the tee the idle straightens right up. Is this tee even supposed to be here? This engine came from a junkyard, I bought the car with a siezed cam, like I said, before the timing belt swap the firewall hose wasn't connected at all, so can someone tell me the proper location for this hose?

Broke the nub off of the vaccum chamber while I was fiddling with it. :( Back to the junkyard I guess.

Here are some pictures of what i'm talking about:

Image
Image

Re: Timing belt troubles

Posted: April 22nd, 2010, 10:57 pm
by OkieOFT
Heh, just found the vaccum hose routing diagram in the shop manual. Looks like it goes to the charcoal canister.

Re: Timing belt troubles

Posted: April 22nd, 2010, 11:56 pm
by OkieOFT
Woo fixed it! So glad I don't have to tear it down again. Also, the hose I said was coming from the firewall actually connects to the airbox and runs to the EGR solenoid. Don't know why I thought it came outta the firewall, kinda hard to see stuff with nothing but a mini mag light to see by.

Which brings me to my next question - how vital is this airbox to EGR hose? the nipple on the airbox is broken off, i'll definately get it replaced but how much will it affect the car?

Re: Timing belt troubles

Posted: April 23rd, 2010, 8:39 am
by Ryan
If you're talking about the one I'm thinking about, its completely non essential. Its pre-VAF, so its unmetered air... also unfiltered.