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T-bird Tim
01-04-2006, 11:10 PM
My car has a noisy valvetrain when accelerating and isnt running as strong as it should. I run only premium unleaded fuel but it sounds like I'm running cheap gas. Check engine light comes on when accelerating but goes away at highway speeds. I know it has a tapping lifter but that shouldnt cause this kind of problem. Does this sound like detonation? I have many upgrades with factory computer chip and settings so I know it needs a tune but I dont want to do that until I replace the lifters. Any advice would be greatly appreciated.

David Neibert
01-05-2006, 12:49 AM
Start by checking the codes. I doubt it's the lifters.

David

RBH Racing
01-05-2006, 09:43 AM
Sounds like detonation, not lifters. They would'nt quiet at highway speeds.

Randy N Connie
01-05-2006, 12:19 PM
I had a lifter ticking sound after I changed my head gaskets.
It turned out to be a small leak around one of my exhaust header
flanges.

Randy

T-bird Tim
01-05-2006, 10:18 PM
This may be a dumb question but what exactly is detonation and how do I fix it?

fturner
01-06-2006, 08:40 AM
Simple....... and as you said....... GET A TUNE!!!!!!!!!!!!!!!

So many folks put all this new stuff on their motors and expect that good ole little stock computer to "automatically" adjust to these changes..... last time I checked it doesn't have AI built into it. But then they start looking for other solutions cause its gotta be something else :cool: .

I often wonder how many perfectly good cars end up being scrapped 'cause it wouldn't work right after a bunch of upgrades have been thrown at it......

Ah to have the good ole days where you could throw stuff at a car, then tune the car yourself, like the carb and timing etc....

Oh well
Frit

T-bird Tim
01-06-2006, 05:02 PM
Still didnt answer my question. What is detonation? And yes I know that I need a tune, I just cant find anyone around here to do it. Doesnt seem like it would be that hard if you had the equipment. Can the stock computer chip be used to retune the car or do I need to have a custom chip made along with the tune?

S_Mazza
01-06-2006, 07:01 PM
Detonation is when the fuel-air mixture ignites too early. It puts a lot of stress on the engine. It's the same as knock. Ping is a mild version of this. Detonation can be caused by timing too far advanced, fuel octane too low, compression too high, cylinder temperature too high, hot spots on the head or piston, plugs that are too hot, mixture too lean. Maybe other things?

What mods do you have on your engine? When did the problem start?

T-bird Tim
01-06-2006, 09:37 PM
I bought the car with all the mods in place so it's been this way since I've bought it. Mods are 76mm MAF, 85mm T-body, 3.5" SCP cold air kit, all billet overdrive/underdrive pulleys, 42lb injectors, 255lph fuel pump, stock supercharger and intake w/10%overdrive. There are other mods but they have to do with the gears and transmission, not the engine.

83GT460
01-07-2006, 04:37 AM
I bought the car with all the mods in place so it's been this way since I've bought it. Mods are 76mm MAF, 85mm T-body, 3.5" SCP cold air kit, all billet overdrive/underdrive pulleys, 42lb injectors, 255lph fuel pump, stock supercharger and intake w/10%overdrive. There are other mods but they have to do with the gears and transmission, not the engine.

Have you pulled the computer out from behind the kick panel to see if someone might have also added a chip. It is possible that you may be running with more timing than stock. I ran my car with everything you have plus a few things except I still have stock injectors and don't have issues with detonation unless I use the tune with extra timing added.

Charles

T-bird Tim
01-07-2006, 01:42 PM
I know he told me that there was a new EEC behind the panel but that it wasnt hooked up because it didnt work. I havent gotten around to taking it out yet. I forgot to mention the car also has a Dr Fred cam and roller rockers.

skydivr7673
01-07-2006, 03:30 PM
A faulty EGR system can also cause detonation. But you should get an engine code for that one I imagine.