Quick Help With Knock Problem

[BASS]

Ok, here goes...My old motor, I had a 92 thrasher chip, adj.fpr, stock injectors, hotwired Walbro, and everything else stock. Car ran perfect, 18 psi, 0 Knock. OK, now, fast forward 5 years later (I broke a rod, and car sat for 5 years with only 5 gallons of gas in the tank). I swapped motors, installed MSD 50s, and everything else the same way it was (with the addition of a new knock sensor, all new vacuum hoses, and a new wastegate hose). I swapped to a Testa chip also. Now, I am getting average 6-10 degrees knock at only 1/2 throttle, and sometimes I can go WOT with about 12 degrees. WOT is set to only 15 psi. I am thinking one of TWO things. (A) RUST (i.e. car is running too lean because the rust clogged up my fuel filter, but I put a new filter in), or (B) The chip's timing is too high for the 93 octane. I inquired about this chip, and I believe he said the timing might be too high. Other than that, the car runs very good.

So, to test to see if (B) is NOT the problem, can I swap in my old Thrasher chip and see if I get knock? (Remember, I now have MSD 50s instead). Im thinking the car will run real rich, but if I see 0 knock, then ill know for sure the chips timing is too high??? Can I even get a Thrasher Chip burned for MSD 50s?? Thrashers were the best!!

 

[salvageV6]

I'd do a gallon of xylene to 2-3 gallons of gas, or else next time you need fuel stop at the 100 octane Sunoco for some good pump gas.

Worth the $10-$20 for the test.

However I would drop the WOT boost a pound or two first.

And finally I would verify the timing in the chip somehow, or get a new good one.

Chips are the number one problem with driveability for our cars, with what I've seen and read on the internet the past 10 years.

And yeah, I used to have a Kenne Bell chip. :biggrin:

I think it was calibrated to test the Kenne Bell knock detector.

 

[BASS]

Hmm, good idea..If I just put in race gas and keep the same (supposedly high-timing) chip in, I should not get any part or WOT knock then. I guess this would verify that the chip thats currently in the car IS a high timing chip in which the 100 Octane can support. Sunoco has 100 octane pump gas??

 

[salvageV6]

Here ya go, should be lots of stations in Jersey selling 100 unleaded.

Overview - Sunoco 260 GT100 Locations

You might want to get direct scan to help tune the car, and some scanmaster data streams have spark timing data available 2.1 version.

Part throttle knock can be tricky and more likely in the colder weather, gotta make sure it gets into fuel enrichment with a high enough tps sometimes going WOT is safer.

Don't try it however with your level of KR until you lower the boost or raise the octane level substantially.

Xylene added to the gas tank (fuel injector cleaner component) will help clean the tank and lines and raise the octane, or given a worst case scenario loosen the rust and crud up to clog up the filter or system components.