U said it would be better to set the timing at 10 again and get a chip, also u can give the reply u wanted to now!! I'll tell u why I don't want to do that and keep it at at 20. A while ago I bought a Hypertech Thermomaster chip for my 89 RS 2.8. I put it in, changed the thermostat to 160 and felt an immediate difference. 2 days later I went to start it and it wouldn't start at all, it cranked, but it wouldn't start. So I put my OEM chip in again and it started and I sent the other 1 to them for a refund. I don't think the timing had anything to do with it but, my car has a different engine in it and I don't know what the year it is. A 2.8 with less miles was swaped in before I got it. Maybe some1 can tell me where to look for identification. Anyway, after that, I really wouldn't like to do it again, unless some1 knows why it did that, and which chip to buy. Is there something I can to it that won't cost much thats ok for it, to give it some power again. I can't even peel out like I used to at 33, with it at 20. I already have K&N's, and I'm not changing the muffler because thats new too and it sounds really good!! Thanks!!

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Looking for:

87 IROC-Z L98
84 TRANS AM H.O.

[This message has been edited by IROC-ZTWENTYGR8 (edited October 05, 2000).]

 

Timing that's advanced too far from stock can cause detonation... when you advance timing, you're compensating for the faster piston. Spark travels slower than a piston does (weird, eh?). So even though your plug fires 10 degrees before the piston's at top-dead-center, the spark isn't making an exposion until the piston's all the way up. I hope I explained that right, if not, let me know...

By advancing the timing that far, the plug is going to fire when the piston's just starting to rise up. The air/fuel mixture isn't compressed yet, and you get a wild, uncontrolled explosion.

A mechanic I went to set my timing once. Apparently he didn't tighten down the hold-down bolt for the distributor- a year later, my timing was so far advanced it was off the scale! Setting it back to normal still had the car running poorly- and I thought to check the plugs. One plug was missing the entire center section- electrode, insulator, etc. There was just a hole. Another plug was missing pieces of the center electrode. The other plugs had their gap open up past the stock spec of 0.045".

I'm guessing that some of your loss in power has to do with either some destroyed plugs, or some out-of-gap plugs. At the least, if you don't find ruined plugs, you can clean the current ones with a wire brush, and re-gap them.

You also mentioned pinging. Are your spark plugs the correct ones? Plugs differ in their "heat ranges"... there's cold plugs and hot plugs. A cold plug is designed to suck the heat out of itself, and throw it into the head. A hot plug won't throw the heat away as quickly. You're supposed to use as cold of a plug as you can get, but one that can reach it's self-cleaning temperature. You could have plugs that are too hot in there- a very hot plug will ignite an air/fuel mix without a spark! Crap, I had a website link that would've been perfect for this, but I can't find it. Okay, found another one, not as good a picture tho. Read down the page until you get to the very first picture and it shows how a cold plug differs from a hot plug. http://www.teamcalamari.com/dox/techtips.html

Anyway, you may find that a switch to a plug one heat range cooler might help your pinging. Can you read a # on your current spark plugs? If they're AC-Delco plugs, your 89 should have R43TSK plugs. (3 is the heat range.)

The year of your engine shouldn't matter that much, it's the year of computer & fuel injection system that does. Now if more than the engine was replaced, yeah, that's a problem. A chip will usually give you a good timing curve.

Kevin S played with his timing a bit... I forget how far he went, but he found a point where the engine lost power.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

 

At 10*(which is where it should be)we'll say I ran a 11.10 in the 1/8th.I can't remember what I ran when I did this.I don't have any timeslips right now.
At 14* advanced I lost 2 tenths of a sec in the 1/8th(11.30).I lowered it to 12* and I gained 4 tenths(10.90).
That is the timing I'm still at.
If the engine in your car is the same as the one they pulled and all the computer stuff pluged up correctly you shouldn't have had any problems.You may have just got a faulty chip.

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[This message has been edited by Kevin S (edited October 06, 2000).]

 

The first chip I got from Hypertech was bad and they sent me a new one... On the whole chip issue I recommend chips after, a cat back, pulleys, high flow converter, coil, wires, plugs, and MSD 6A ignition box...

 

Where can u find identification on the 2.8??

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Looking for:

87 IROC-Z L98
84 TRANS AM H.O.