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Discussion Starter #1
OK, so I finally tackled the job of replacing my timing belts, and water pump, and anything else I could while I had it all apart! I used the "cam lock" method instead of removing the valve covers and doing any valve adjustments. The job went well, started at TDC, checked the one camshaft mark I could see, I took my time, marked everything, checked and rechecked everything, the cam locks worked well, nothing moved that I could ever see! etc, etc, etc. Went to start her up and she coughed and sputtered to life but not well...??? No issue with valve and piston "interaction" just seems to be a timing issue to me. Runs sort of smooth with some revs, but will them sputter and backfire, etc ,etc, seems like timing?? Just looking for some suggestions before I tear her completely down again, this time valve covers and all!! Is there any minor timing adjustment on these cars at all ('80 GTSi 2v)??? Is there adjustment to the eletronic modules (adv/rtrd)?? Just wonder and any help is appreciated. - Nick
 

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How did the car run before you did the belt change. If it was OK then something did not go back together right. If you did not touch the dizzy then I would look for a vacuum line being either off or broken. Check all of the connections that you disconnected and make sure they are plugged back in correctly. Also take a timing light and see what the timing is. Like I mentioned if it ran good before then you need to recheck your work to see what did not go back together the same way. Good luck
 

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Line it all back up to TDC and check your marks again. Use a telescoping mirror and a flashlight for anything you can't see. When changing timing belts, it is easy to think you have everything right, but have a one tooth of slack in the belt somewhere, and it doesn't become evident until you tension the tensioners and then slightly turns one of the shafts out of position. When installing a timing belt, all of the spans except the span where the tensioner rides should be very taut before you introduce the tension. (Did I explain that okay?)
 

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Discussion Starter #4
Thanks for the replies, yes the car ran fine before the belt change. I also was careful to have no slack between camshaft gears, and between drive gear to camshaft gear, the slack was on the tensioner side (I hope!!!). Forgive me but what's the "dizzy"??? I've done quite a bit of car work and that's a new one for me??? I do agree and think that it might also be a vacuum issue because in order to get it to start/run I need to move the plenum plate on the fuel distrubutor assembly manually, but also think the vacuum issue might be related to a timing issue, I dunno!!! The chicken or the egg first question, but as I made no adjustment to the Bosch system... I'm a big believer in "if you didn't mess with it, it's probably fine". I did however mess with the timing... Thanks for any ideas and input, I'll try nearly anything before tearing her down again to inspect timing/cam marks!!!
 

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Sorry , Dizzy is short for distributor. OK if you played with the timing then I would go to that and recheck it. I agree that if you didn't touch anything that it should run as good as before the belt change. I would also suggest that you may need to pull the cam covers and check the cam alignment marks. 1st I would take a timing light and check the timing on both banks to see if it is in time. If you pulled the dizzy then it may be off a tooth or so.
 

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Discussion Starter #6
Ya, sorry, kinda figured out dizzy after a minute or two... Little slow on the uptake! As the distributor(s)/rotor(s) are run directly off of 2 of the cam shafts no adjustment is available... other than moving the camshaft, which is what I was trying to avoid the entire time, but kinda thinking I wasn't too successful. Well, on to lining everything back to TDC, check the single cam tick mark and then re-check my paint marks and see if I can tell where I got off, if not start over including pulling the valve covers, and probably shimming the valves if required. Next question, how difficult is all of that with the engine in the car? And how often does one need to shim/adjust the valve clearences? Mine is a 1980 GTSi with only about 30,000 mls. Should I expect much adjustment? Thanks as always - Nick
 

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I don't know how much wear you will get but the normal procedure is to check the valves at the 30K major. I have a carb car so it was not to difficult to pull the cam covers during a belt change. When I did my 30 K I only found 2 exhaust valves out . This was marginal and depending on how you insert the feeler gage it would be out. I changed both shims because I like the exhaust valves to be at the max end of the clearance. So before you pull he covers turn the engine over by hand until the PM1-4 is at TDC (compression stroke) and then pull the dizzy cap and see if the rotor is dead on #1. Do the same for TDC #5-8. If they are OK which I am suspect of then start it up and check timing at 1000rpm on both dizzy's.
 

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Discussion Starter #8
Well sounds like I'm on the right track to just check things out and see if I can "reset" whatever I got out of place, if not on to the full deal. Maybe the whole cam lock method isn't the best idea...??? Hopefully might just be off a cog and can realign that. Just for curiosity sake how many teeth could a person be off before the valves and pistons collide in an unfortunate meeting? Will give all of your suggestions a good honest try and see how things turn out, thanks again. - Nick
 

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There are others that have the correct knowledge but I would say if you are off 2 teeth then you have a problem. You already started the engine so if you did damage then it is done. But before you pull the cam covers remove the spark plugs and turn the engine over by hand and listen for the compression in each cylinder. I would install a compression gage in the cyl. and see if you get a reading. Even turning by hand you will get a small compression buildup. If it stays at 0 then I would think you may have bent a valve. I don't recall but how did it run when you started it. Did you have a MISS when listening to the exhaust . Did it just idle poorly like it was laboring , not steady. Did you drive the car. Hopefully you are maybe only 1 tooth off on one of the cams. The only way to verify would be to remove the cam covers and check to see if the marks on the cam and bearing cap are aligned. You need to do this on all 4 cams. Good luck
 
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