Hi guys,
I have a 1999 coupe and I hear it ping between 1400 to 1800 rpm especially when it's in 6th gear (also does it in 5th). It also seems to be getting a little worse as the days pass.
These are the mods on the car:
1. 2004 LS1 heads that were planed slightly.
2. 2002 Z06 camshaft.
3. ATI underdrive pulley.
4. Cold air intake.
5. JBA shorty headers.
6. Cat back exhaust (came with car, I think it's a Corsa)
7. Bosch Platinum Plus4 spark plugs.
8. MAF screen removed.
9. Z06 transmission
10. Z06 shocks and tires on 2004 thin spokes (not engine related but I'm on a roll .) The previous owner also lowered the car by cutting the bushings in half.
The car runs really strong. I went head to head with a 2007supercharged Saleen S281 with 4.10's and we were bumper to bumper up to 120. The S281 is supposed to have 465hp and 12.2 in the 1/4. I think I would have actually taken him if we had gone faster.
The exhaust is really loud only when you pin it, but it's actually quiet cruising at highway speed in 6th...so I can hear the pinging.
I have not had it tuned, no dyno or track runs yet.
I run 94octane and even added an octane booster on the last fill up.
I was thinking of doing a Terraclean which is one of those fuel injector/decarbonizer systems done at the dealer.
Any advice would be greatly appreciated.
Thanks.
Mark

 

Needs more fuel or a little less timing at lower rpm.... Have it tuned

 

Get it tuned ASAP..pinging can distroy the engine.

 

The heads being planed brings back some memories for me. Long time ago i had some milled heads and it raised my compression to the point that no gas would satisfy it. So I pinged.

Before you spend a ton at the dealer, try to decarb it yourself with Seafoam - lots of "how to" on this forum. I have no experience with those plugs so maybe someone else can chime in.

I agree with sleeperc5. Pinging kills.

 

NGK TR6 plugs, change after the carbon cleaning

 

Thanks guys.
I'll have it decarbonized and then have it tuned.
My brother-in-law had his Ram-air T/A tuned locally at Zekes (they used to do all the SLP Camaro/firebirds up here), so I'll give them a shout about dyno tuning it.
I'll let you know how it goes.

 

1st bit of advice if it were my car would be to put the screen back into the MAF--Especially if you have NOT had it tuned--You are getting mis-information as to the fuel curve and it needs to be recallibrated to use without a screen--I would just leave it in period--maybe only 2-3 RWHP gain--and not worth the drivability issues it creates without it--second I would install copper plugs --NGK TR55--best for getting rid of heat in the plug that causes hot-spots which can lead to pinging--Its odd that you can hear the ping--the job of the knock sensors is to remove spark timing to eliminate the ping--yours doesn't seem to be reacting fast enough to catch the ping---98's were notorious for bad knck sensors--don't know about the 99's--Follow up on them
And as others said--more fuel at the low grams/low RPM places--make sure your LTFT's are in line--and take some timing out down below--all those mods--deff. in need of a tune---

PS : stay out of 6th gear while putting around !!

 

all good points. With my new heads and cam change I had a ping..changed the the NKG TR55 plugs and that took away the ping.
My $.02

Sleeper

 

Thanks guys!
I really didn't think that going from platinum plugs to copper plugs made sense, but I'll have to try it.
I'll let you know if the pinging stops.
Mark

 

If its in closed loop, and the commanded A/F ratio is stoich, as I'm sure it is, adding fuel in the lower rpms will do NOTHING, except make it have to correct less. You can add all you want, the pcm will make sure its 14.7:1. Add too much and the pcm will start taking it back out.
The exception being if the fuel trims are maxed out. And if they are, somethings wrong, and a tune is just covering it up.
Before you put the screen back in your MAF, clean the hot wires carefully with some electrical cleaner and a q-tip. VERY CAREFULLY.
Dirty MAFs are the #1 cause of ping, hesitaton, and skewed fuel trims, at least on stock and near stock vehicles.

 

Thanks edcmat.
I'll take the meter out, have a look at it and see if it needs to be cleaned.
The screen was thrown out once I removed it, so putting it back isn't an option.
I did the carbon cleaning... the idle is a little better, but the pinging is still there.

Thanks,
Mark

 

Hi guys,
I looked into the NGK TR55 spark plugs and I can't find them in copper.
I even went on the NGK website and they don't even seem to make them anymore.
The ones that I did find are the NGK TR55 platinum and the TR55 Iridium. Will these be as cold or as good as the TR55 copper?

I will also remove the mass air and see if it's dirty while I'm at it.
What kind of cleaner should I use?

Thanks,
Mark

 

Electrical cleaner, or even non residual brake cleaner.
But now, several companies sell MAF cleaner in a spray can.
Spray the front side of the hot wires, and blow dry gently with compressed air. You can spray right through the screen.