I have been chasing this problem for a while now, and have about ran out of ideas.

Basically, when I am pulling in 2nd or 3rd, I get random pings in the area of 4500/5000 and of course even this doesnt happen all the time. Sometimes it wont happen for a while (days). The wideband shows safe AFRs when this happens (11.0 or so). And its only one or two pings.

Any ideas?

 

It sounds like your right at your boost limit, like right on the edge, thats all I can think of.. Im new to the forced induction scene, so we'll wait for others to give their two cents.. im just speculating
sorry I couldn't be of more help.

 

I doubt if it's that, that wouldn't cause the engine to ping. Plus IIRC he's running a BNR stage 4

As far as the problem, that is quite an odd one. I assume you've checked all the basics like timing and such right?

 

What are you tuning with (EMS?) Sounds like a case of too much timing (assuming you're using at least 91octane gas). Do you have an EGT gauge?

 

Well, timing is set at stock, which I am guessing isnt quite correct. I am going to go ahead and back it down about 3 degrees tomorrow. And yes, its a BNR stage 4.

 

Well... EMS is stock, using an SAFC *runs and hides*..

And for fuel, I run a 50/50 blend of 100 and 91.

 

Spark plug wires crossed?



-Ted

 

Man, Rat wouldn't admit it if the wires were crossed, lol...

Anything getting knocked loose with all these walls you're hitting?

Do you still have a working capacitor on your ignition timing circuit (below the trailing coil pack)?

 

how much boost are you pushing? Now I don't know much about what you have but with the rtek I'm getting it retards timing 1 degree for ever 1lb of boost. The stock boost sensor automatically retarded timing up until 9psi but not after that. Are you running ems???


ah never mind you are running stock ecu so yeah you will need to retard your timing. check the rtek out of you are on a budget it may be something to be interested in. especially when they develope the data logging with the 2.0 chip comming out at the end of the year. I'm sure you are running more than 720cc secondaries so you will still need the safc with the 1.7 chip however with the 2.0 chip it has a built in safc. check it out www.pocketlogger.com oh yeah you will use a palm piolet to data log with the 2.0 chip, any cheap palm piolet

 

What about an rtek ecu upgrade? They have timing retard under boost and seem to do a good job of it

 

I'd point to overadvanced ignition timing or overheated intake temps.

Are you still running the top mount?

for a cheap fix try retarding overall timing at the CAS 4-5 degrees

 

I vote for the intercooler idea if Mr Rat is still using a stock intercooler (gheto water spray also???). He lives in Arizona. I used to see over two hundred degree intercooler intake temps with the stock intercooler. Scared me enough to buy a front mount intercooler.

 

JRAT take a look at this,
http://www.autospeed.com/cms/article.html?&A=0353

it might help you to tune out your problems.

 

LOL!! I hope not, but for ***** and grins, I will check that.

 

We talking about the one that is attached to the slave cylinder? Otherwise, I am not sure what your talking about.

 

Let me try to answer the rest of these..

I am not going to get the RTek, because I am going Haltec in a few months.

Yes, the TMIC is still installed (but is getting replaced this week with a Greddy FMIC)

Yep, still TMIC. Sometimes I never learn. Even though temps are very reasonable right now.


I appreciate all the input you all are giving me! Things I am going to do for now is, retard timing about 4-5 degrees. Correct me if I am wrong, but that means moving the timing TOWARDS the trailing mark (which is 5 deg ATDC IIRC). Check plug wires, and hurry up on installing my TMIC.

Rat

 

Backed timing off, pinging got worse.... Its between the leading and trailing timing mark.

This is J-Rat

 

maybe you need colder plugs?

 

9s all the way around. This problem just surfaced outta no where!

 

I guess you're gonna play with the timing a bit more, eh?

The cap I'm talking about is a different one than the slave, located near the gang ground, under the trailing coil pack. Can't miss it, looks exactly like the slave cylinder one. Helps protect the puny timing signals from EMF interference...Just a long shot, only thing I could think of at the time

 

Even if the marks on the coils are correct, verify with a timing gun that they are firing in that order.


-Tedh

 

Verified with a timing gun. leading and trailing. All marks were lined up, timing is now retarded 7 degrees. Fuel is 50/50 blend 100 and 91. Boost is 12 PSI, and AFRs are mid 11s across the pull.

After timing retard, pinging got worse... ALOT worse. Under detonation, AFRs were high 11s.

Only thing that I can guess now is intake temps, but ambient was reasonable for conditions... I have ran harder under hotter conditions..

Wierd...

 

Humor me here. What wideband O2 sensor are you using and how long has it been in?

 

high 11's is pretty agressive considering your probable high intake temps...try richening it up a bit

 

Wideband 02 is the Innovate LM-1. Its been installed for a few days.

I can go ahead and richen up to the 10s...


Correct me if I am wrong, but miving the timing marks CLOSER to the trailing mark is retarding?

Thanks for all your help so far!