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still have KR

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seeyabye

Member
Joined
Sep 30, 2003
Messages
641
Why do I still get 1-3deg of KR? My car is an 87 WE-4 that is mostly stock. It has a hotwired Walbro 340, Accufab adj. Fp reg, Adj wastegate actuator, 3" downpipe and testpipe, K&N cone, RA 93 chip, RJC powerplate, and DIY alky. I am only running 18psi boost with 40psi fuel pressure(line off). The alky is set up to come on at 12psi. My o2s are in the high 800s. I have a TA 49 and 009's but I dont want to put them on until I get this alky straight. Any suggestions would be appreciated.
 
Is it from a dead stop to wot thru the gears? What mph does it knock? What size jet? Pretty low knock numbers......maybe it's going away as you accelerate. Try a lower turn-on.
 
It seems to knock mostly in first and second gear. If I stay on it, usually the knock clears up. When I turn off the alky, and lower the boost to 14psi, no knock, but at 15psi, usually 1-3 deg. In the past, I have been able to run as much as 22psi by mixing in 5 gallons of 110 with 10 gallons of 93. I used whatever jet was recommended in the recipe for the DIY alky. I don't remember what size it was. I appreciate all the help guys.
 
Oh Yeah, I forgot to mention, changes in fuel pressure have not seemed to affect the o2 mvs. What kind of fuel pressure should I be running for my set up? Does 40 psi sound right?
 
I think it'll help if you lower your alky turnon to 8-9 lbs. This should eliminate your low end knock. Not sure why your 02s are as high as they are. With the same setup as you, and even a reds 93 chip, I had my FP set at 43, line off, with 02s in the low 800s.
 
If the jet is too large, it may spray too much alky. The recipe is intended for 23 PSI not 18..so it may be you are spraying too much alky. Cuasing the motor to surge. Lower the pump pressure or reduce nozzle size.

Every car is different as to fuel pressure. And FP is determined by fueling within the chip. Also some chips lock the blm's commanding fuel to be dropped in at higher boost levels..

Do you have access to direct scan?

See no knock at 14 PSI means everything is working as should. well at least to get you to this point. Now the trick is to add alcohol in the correct amount to quench the detonation above the 14 PSI you run. Too much can/will make the motor surge/knock. Try dropping your fuel pressure. At idle they should be 128 or approx.. typically. WOT in third gear look for mid-high 700's.

You can try putting a pressure guage in line with the nozzle and see what pressure the pump is putting out.

I'll leave you with these crumbs :)

hehe

Julio
 
If i ever get off work, I will try some of the suggestions. I don't have access to direct scan, but am in the market for a laptop based scan tool. Is direct scan the way to go? How much is it and where can I get it? Thanks to all for the suggestions, I'll keep you posted.
 
OK, I had a chance to play with the car a little. Tried raising the FP to 43 psi, no change. Tried lowering the alky turn on point to 10 psi, no change. Tried raising the boost to 20 psi, still no change. After raising the boost, I have noticed a little stuttering and slight hesitation in the higher RPMs just before it shifts. I have also noticed that the KR is not consistant. Sometimes I can step on it and get no KR, and other times, the Knock gauge lights up all the green lights. I no longer have access to a scan tool, so that will be my next investment. Any ideas on where to go next and also some recommendation on a laptop based scan tool would be greatly appreciated.
 
Direct scan.. sounds like your car has too much fuel/alky.

Fuel pressure has to be setup for the BLM's.. and I would take out fuel not add. Likewise drop alky pressure by turning the screw on top of the pump counter clockwise 1/2-1 turn.

You need a scan tool to adjust the car. The knock guage is cool..but you need to see where the knock is occurrung and take it from there.
 
Thanks for the quick reply Razor, where do I get direct scan? I have also noticed some strange things watching the o2 mvs. Sometimes at idle, the 02s will drop to 0.00 and the car will start to idle rough. Once I give it some gas, and start driving, it clears up. Could my o2 sensor be bad? Could this have something to do with my o2s being high at wot? It does this with the alky on or off.
 
http://www.bmcomputersource.com for the DS

You have issues.. fix those issues before going with the alky. No data so I dunno.. I dont pay attention to O2's at idle. 17 year old car..it can be anything.

Do some reading on tuning the car..learn bout the blm's,tps,iac, etc.. get these in line and usually everything else falls into place.
 
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