Is it possible for an engine to ping only when cold (less than 80 degrees)?

 

Are you sure it isn't the valve train chattering? That sounds more likey then pre-ignition pinging. A valve adjustment will usally fix that.

 

It could also perhaps be piston slap depending upon the internals. What's the setup?

 

Teh previous owner had a rebuild on it. The compression has been increased to 12.4 but the pistons are stock pistons which were grinded to accomodate the valve to piston clearance. My PowerFC picks up slight knock when the ticking occurs. Can a skimmed head and modded piston cause this? Can a dying fuel pump cause this as well?

 

bump.

 

tuned ecu or stock?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by garyc17 &raquo;</TD></TR><TR><TD CLASS="quote">bump.</TD></TR></TABLE>

There is no bumping in here

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00TypeR1071 &raquo;</TD></TR><TR><TD CLASS="quote">There is no bumping in here </TD></TR></TABLE>

It depends on who you are.

 

Tuned ECU.

 

define tuned, cause iassure you its only pinging because its either really lean at idle or something at that nature, its a tuning problem, i dont think ur cr is that high.

 

wow are u sure ur compression is that high? You tuned the car with a power fc??

 

my car pings when cold. And when hot. Pings with the tuned ECU, or the stock ECU running the knock sensor.

what to do? (obviously 91 octane + booster isn't cutting it) and the crazy thing is, the car "used" to run fine. This only started about 3 months ago.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pvt_awol &raquo;</TD></TR><TR><TD CLASS="quote">my car pings when cold. And when hot. Pings with the tuned ECU, or the stock ECU running the knock sensor.

what to do? (obviously 91 octane + booster isn't cutting it) and the crazy thing is, the car "used" to run fine. This only started about 3 months ago. </TD></TR></TABLE>
Very simple answer actually, should only take commen sense..
if a tuned ecu and high octane isn't cutting it,the only two things left to do are
Thicker Hg, and Colder plugs.

 

Higher Hg? Plugs are stock 7 range. If its' pinging, the powerfc would have picked it up on the knock readout. Its not doing so although it does fluctuate very slightly during the ticking. Can LMAs be the mastermind?

 

have you checked the timing at the distributor? Should be 16 degrees. I would try retarding it 1 or 2 degrees to see if that makes a difference... If so, then that gives you something to go on; perhaps needing a retune.
If you have the Commander, does it show the degrees of timing? Let us know what it is while warming up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraType-R &raquo;</TD></TR><TR><TD CLASS="quote">
Very simple answer actually, should only take commen sense..
if a tuned ecu and high octane isn't cutting it,the only two things left to do are
Thicker Hg, and Colder plugs.</TD></TR></TABLE>


that is the obvious solution, but it doesn't make any sense that the car would run so well for so long, even getting tuned, and then all of a sudden start having this problem.

while looking to the obvious, I'm thinking that I skipped a tooth on the cam gears. That is causing the timing to run advanced, and thus pinging no matter what I do.

I ordered up a new VC gasket, and I'm gonna check the timing on the gears.

 

The commander shows that it is 16degrees when the car is fully warmed up. The marking on the crank pulley fluctuates alittle when I use a timing gun. So how would I know it is dead on 16degrees?