Bad Knocking Problem....HELP

[Mike from Jersey]

I have had my truck since it was new and never heard audible pinging, until now. It is so bad that it pings audibly at part throttle, on T17 of the Ultimate. My scanner shows 12-13 degrees KR at just a quick stab of the throttle. I always keep everything well maintained, new plugs (CR42TS), wires relatively new, fuel filter, oil change, PCV,etc. Previous I could run the T2- 20 program on 94 octane with less than 6 degrees of KR. O2's- 910-930 at WOT, fuel pressure under boost comes right up. 45-47# at idle hose off. A couple weeks ago truck ran 12.20 on pump gas on a warm day. So something all of a sudden must of gone out of whack. :banghead:

Mods
Stock internals
ATR setup w/TE44
ATR IC
UChip w/Ford blue tops-36#
MSD 6 w/coil

Any help or ideas would sure be appreciated.

Thanks,
Mike :banghead:

 

[leroy]

Any chance you got some bad gas?

After that, double check all ignition stuff, and vacuum lines. A vacuum leak in the line to the fpr or map sensor can really screw things up.

Jim

 

[TurboTony]

Maybe an intercooler pump/leak or something?


Tony

 

[Mike from Jersey]

Jim
I put some new 94 octane from a different station...no change
Also checked those vac lines. I have "in the cab" Auto meter fuel pressure gauge that comes right up as boost goes up.

Tony
I checked the IC level and it was up to the top.

Thanks for the input guys.

 

[Pittman]

Is the IC pump running?

Double check timming, dist still tight? Cap and rotor?

I guess you have datamaster. What are the intake temps at time of knock and is it lean?

It has to be something kinda easy to find if the truck all of a sudden took a turn for the worse with this. Thats sounds like a MAJOR change.

 

[Mike from Jersey]

Is the IC pump running?

****actually I have 2 and they are both operating.****

Double check timming, dist still tight? Cap and rotor?

****Checked them both****

I guess you have datamaster. What are the intake temps at time of knock and is it lean?

****O2's between 910-930. Intake temps 75-80 @ cruise, 95-100 @ WOT****

It has to be something kinda easy to find if the truck all of a sudden took a turn for the worse with this. Thats sounds like a MAJOR change.

****Yeah I agree, maybe a distributor problem, or EST module????****

Thanks for the suggestions
Mike

 

[Captain Morgan]

could this be ECM related by chance? Just throwing it out there.

 

[Pittman]

Damn

Well Mike am out of ammo on this one. Make sure you keep up the post so the rest of us can learn from it. I dont know how to test the dist but that would be a cheap place to start.

V6 Kompressor would probably have some ideas on this.

 

[Mike from Jersey]

Morgan,
The ECM is definitely on the list to check. Thanks

Pittman,
I have a new, not rebuilt, GM distributor that I just picked up last week. I will install it asap. I will let everyone know as soon as the problem ois solved.

In the meantime any other suggestions are welcomed.

Thanks guys,
Mike

 

[Captain Morgan]

Mike,

if you need another ECM to try, let me know. I can see if I can get up to you sometime soon and help out, I have off tomorrow, and this weekend, and its not like my truck is going anywhere any time soon...... :roll: Besides, I still havent met u yet....lol

 

[Loeryder]

I have a new, not rebuilt, GM distributor that I just picked up last week. I will install it asap.

Do you have a part # for this NEW distrib?
I was told by more than 1 GM parts supplier the distributors are NOT available new, only rebuilt, or buy all the parts to rebuild yours yourself.

Maybe they were all wrong, but I'd like to run a part # by one of them if possible.

Let me know where you got a NEW OEM distributor.

 

[Mike from Jersey]

I have a new, not rebuilt, GM distributor that I just picked up last week. I will install it asap.

Do you have a part # for this NEW distrib?
I was told by more than 1 GM parts supplier the distributors are NOT available new, only rebuilt, or buy all the parts to rebuild yours yourself.

Maybe they were all wrong, but I'd like to run a part # by one of them if possible.

Let me know where you got a NEW OEM distributor.

I picked it up on Ebay. Where he got them ( he had a few, who knows) but your GM parts man is correct, you can only buy the parts to rebuild your original. A rebuild is available through most parts stores (NAPA etc)

Morgan,

Thanks for the generous offer. Could you please email me your phone #. Will you be going to Etown for the GM High Tech day this Saturday? Let me know.

Thanks,
Mike

 

[Captain Morgan]

Morgan,

Thanks for the generous offer. Could you please email me your phone #. Will you be going to Etown for the GM High Tech day this Saturday? Let me know.

Thanks,
Mike

You got mail

 

[ghettosled]

check your fuel delivery if you havent already. make sure pressure is not dropping, 02 volts are good, and mat's are still the same as b4.

I would tripple check ignition, and replace plugs and wires even if they are *relatively new*. also check to make sure msd is working ok.

hope this helps

 

[V6 Kompressor]

one thing will do it, carbon build up in the combustion chamber, especially on the stock heads around the exhaust valve. Try the sea-foam cleaner (gm's cleaner is the same) follow the directions or do a search for upper intake cleaning... Car-Quest / Napa sell's the cleaner under the trade name Sea Foam... GM"S part number is here on the BBS somewhere http://www.syty.net/phpBB2/viewtopic.php?t=11175&highlight=upper+intake+cleaner

http://www.syty.net/phpBB2/viewtopic.php?t=9596&highlight=upper+intake+cleaner