Still have KR


Sep 30, 2003
Recently, I have been getting KR on my 87 WE-4 at 3/4 to full throttle with the alky on and boost set to 20 psi. I disconnected the alky and turned the boost down to 15psi, and I still have KR. I am pretty sure that it is not false knock, sometimes it is audible. Any ideas on where I should start? My car has a hotwired Walbro 340, Accufab adj FP reg, adj WG actuator RJC powerplate, Kirbans 3" DP, gutted convertor, DIY alky, RA 93 chip, and a K&N open element. It also has a new AC Delco PCV, AC42 TS plugs gapped to .034, Coil pack and Ign module, ECM, Map sensor, Maf sensor, and Magnecore 8.5's. I don't have Turbo link or Direct scan, but I do have a scan tool. Thanks in advance.
Umm id recomend not jumping to those conclusions yet and scaring yourself, i didn't see new fuel filter on your list of new stuff, what about checking for bad grounds grounds? Have you checked to see your regulator and pump are actually putting out 1# of pressure for every pound of boost? Turn it down past 15, to 12-13 and see if it still knocks. What are your 02s on the scan tool? What fuel pressure are you running, hows the alternator voltage?
I didn't see you mention the mileage. If over 100k, I would take a good look at the injectors as well.
As mentioned by another poster, I'd make sure the FPR is working properly. I bought a used Accufab, and started to see BAD knock during boost spool up. I posted it and got a PM from someone who experienced the same thing with the Accufab. I don't believe that 2 users reporting similar problems compared to the number that have no problems to be reason for alarm, but it's something to consider. Neither of us still use the Accufab, and I have gone back to the 237 regulator myself. Just a thought.

Also be sure the injectors are clean and flow matched, again already mentioned.

Your situation is lean, probably to the point of misfire. Racetronix, out of Toronto, has the fix. Try them!
My car has a new fuel filter, and the regulator is able to supply 63psi @20psi boost. The fuel pressure is set to 43 psi line off The alternator is charging 14.52 volts. The car has 126k on the original motor and trans. The injectors are original. I ran some BG 44k through the gas and the intake in an attempt to clean them. I tried mixing in 5 gallons of 110 with 10 gallons of 93, and the KR went away. I was able to turn the boost up to 20psi before it came back. I took the car up the road to see what my 02s were reading. In third gear WOT, the 02s are around .80. It seems that if I stay in the gas, they go to around .74-.76. I have a hard time getting any reliable o2 readings because I think my car accelerates faster than my scan tool updates. These readings were taken in third gear. While searching for the high BLM gremlin, I found a bad EGR valve. Could this be part of my problem? Would high BLMs(138-150@idle) cause knock at WOT?
Oh, I also have a set of 009s and a TA49 still to put on the car. Should I try swapping out the injectors and have a new chip burned? Or should I try to fix this problem with the stockers in place?
Change those injectors - too many miles. Also. I recommend changing (1) part at a time for diagnostics sake ;)

If that does'nt cure it check the sensor located on the P/S wheel well, I cant remember whats its called at the moment for some reason :confused:

Turbosix- are you talking about the map sensor? If so , it has already been replaced. Thanks for the response.