Hey Fella's, I've got a problem I have never run into before. I cant time my 2.8 with a light. First a little back ground; Ive been a mechanic my entire life, I'm 62, (its not my first rodeo), I've been building fast cars all my life,mostly sports cars. I'd say I have a fair bit of experience. That said, I have a situation new to me. I have gone thru the ignition timing sequence several times and can not get the timing mark visible at the mark. The grooves on the balancer have all been painted, TDC groove highlighted, ALDL jumpered to base mode. I can not get any of the marks anywhere near 10* . I have tried using all the wires, including the coil wire as the trigger. My suspician is a slipped balancer ring or a sheared/ missing crank key. I have set the large timing groove to 10* and the #1 piston is nowhere near TDC. I can time it by ear, and it runs quite well. I'd like to set it properly. Any ideas? I hope you guys can teach this old dog a new trick or two.
On a 20 year of car original it could slip. What I do to check it is take an old spark plug and knock the guts out of it. Weld or glue a bolt in the end to it sticks out about 1/2 inch. Put it in the #1 plug hole. (be sure the piston is down) Unplug the coil to be safe. Then slowly turn the enging both directions until the piston contacts the bolt. put a mark at TDC each place it stops. You timing mark should be inbetween the marks. If not you know it slipped.
There are at least a half dozen guys on PFF that have experienced slipped rings on their harmonic dampers, so it's relatively rare but not unheard of. There are several threads discussing it too, if you do a search. I believe PFF member Phonedawgz posted a few close up photos in one thread that showed the relationship between the timing groove and some other feature on the hub. If they're not aligned, then you know the ring has slipped.
It's not too common, but does happen every so often.
The fun starts when you go to buy a new harmonic balancer. As far as I know, they aren't made specifically for the Fiero anymore. So you have to buy a balancer for another vehicle with the same engine, and scribe your own timing mark.
[This message has been edited by Blacktree (edited 02-05-2014).]
Dodgerunner Said it ! . I've been building cars since the early 60s and only experienced it twice ! I did the same thing with and old Plug to check "True TDC"
Because it happened to me, I sort of follow how often it's reported here... and I wouldn't say it's all that rare. With the original harmonic balancers being 25 years old or so now, I suspect the problem will only continue to get worse.
I posted the following five years ago...
quote
Originally posted by Patrick:
I had rebuilt my distributor, so I needed to time the engine when I put the distributor back in. I had never worked on a 2.8L engine before I bought this '86 GT in March (as my other Fieros are Dukes), so everything/anything I'm doing on this engine is new to me.
Well, no matter what I did I couldn't get the dog-gone engine timed properly. When I followed the proper procedure, the engine would stall at 10 degrees BTDC.
To make a LONG story short, it appears the outer hub of the harmonic balancer has spun on its rubber mount. Just my luck the FIRST time I ever try to time a 2.8L engine, the timing marks are all screwed up.
Anyway, just for now I've inscribed a new timing mark on the harmonic balancer. This mark really is at TDC. Once I did that, timing the engine was a piece of cake.
If anyone has a good used harmonic balancer in their stockpile of spare parts, please give me a shout!
Notice the dreaded red X in the follow-up post where a non-PIP hosted image had been copied and used.
quote
Originally posted by Patrick:
Finally got a harmonic balancer to replace the one which had “spun” on my GT. Here’s a picture of what I saw after I took the crank pulley off. Notice where the main timing mark and keyway are.
Now compare the relationship of the timing mark and keyway with this image that JazzMan posted of a good balancer.
Had a heck of a time finding a long enough metric bolt at various hardware stores to use to pull the replacement harmonic balancer back on!
Here's how the main timing mark and keyway are supposed to line up with each other on a Fiero 2.8 balancer.
[This message has been edited by Patrick (edited 02-05-2014).]
I forgot who it was - but someone on here mentioned having (or knowing someone who had) a car where the outer ring would continue to spin for several seconds after the engine was shut off. The rubber sleeve in between the hub and the outer ring was entirely gone!
I wonder if harmonic balancer problems are not more common. Belt squeal is one symptom of a bad harmonic balancer, for instance. The Damper Doctor in California seems to be the only source for correct balancers and they were out of stock when I needed one last year. They will rebuild yours if possible, but that's a lot of shipping for much of the country.
My 4.9 calls for 10 degrees of initial advance. Set with a timing light, it won't pull a fat lady out of a donut shop. I added advance until I got just a little bit of ping, and then backed it off a degree or two. Ended up being something near an "additional" ten degrees. Runs great, now, set "by ear".
I really don't have any problem leaving it that way. I always used to set my advance by ear, as did my dad. If I ever have to do anything else to that end of the motor, I may pop for a new balancer. Otherwise, it's good as it is.
They claim the balancer is kinda critical to saving your engine from shaking itself to pieces. Something about the crankshaft and related parts can fail. BTW ATI (at Summit Racing) has balancers for the Fiero, for three bills, plus, and they don't look the same. I'm not sure how you put the pulley on.
Setting the timing is something I still have to do on my 2.8. I am close now but I know it could be better and a slipped ring is something I didn't know about, thanks for the heads up!
I replaced my balancer with a part from The Fiero Store, but I think you have to let the installer that he has to mark the replacement differently from the original. TFS will tell you exactly what to do. I was lucky that I replaced my harmonic balancer when I did, since the stock piece (86 GT) was literally falling apart. 28 years is a long time to hope that some of the moving parts will last much longer.
