trying to tune for no knock.... not working


Dec 15, 2001
Hello all, I got a ScanMaster 2.1 yesterday and installed it that night. Today was my day to see what it can tell me about my car. I reset the IAC, and set the TPS, then I wanted to tune for no knock at all. Right now the BLM's are at 105-106 driving (115 idle), while the O2 millivolts are at .780-.810, and KR anywhere between 1.x and 4.x, up to 6.x and 7.x once. This is on 93 octane, the Casper gauge detects knock around 10psi. Unfortunately I do not have a FP gauge, I had to return it because it had a leak. I have turned up the FP little by little. But the BLM's appear to be quite rich, and I'm still knocking.
Another thing with my car, when I give it WOT, the boost shoots up to 10psi, then hesitates, and climbs to 15psi. I recall in my Mr2, when you give it boost, it instantly boosts whatever the wastegate is set for max. Can anyone give me advice on this?

Walbro 307 hot-wired
adj. FPR
Poston's chip
adj. wastegate rod
9" cone filter
torque strap even

I think that's it.

On the boost, check and make sure the wastegate arm is not sticking/binding. See if this helps your knock. Recheck lines for vacuum leaks that can cause a rich condition as well as to much fuel. Swap chips with someone. Each chip is different. Sometimes it is impossible to get 0 knock. I can live with 3-4 on pump gas just getting on it but becareful in full 1/4 runs. You can add xylene to help determine if the knock is real or false.

Sounds to me like you have the Fp up too high and also have an octane induced knok problem.
You don't say what the boost is set to. However, w/ that much fuel being pulled, you may get a "rich knok".
My suggestions:
1. A FP GA. that's accurate on the W/S and a WOT blast to verify the fuel system is keeping up w/ boost.
2. Set the FP to somewhere in the low 40psi. Do it again.
3. Add a couple gallons of xylene to the gas and see if the knok goes away, if so, it's octane related.
1. Does the car have the orig. cat on it??
2. Whats the voltage across the pump, engine running?
3. What's the chip have in it for timing?
4. Has the ign system been optimized?
5. Headers cracked?

When the boost rises and hesitates, it could be knok is pulling timing. Does the knok and loss of boost rise occur at the same time?

Try another chip makers chip...;)

Thanks for the replies... my first post says that boost shoots up to 10psi, then climbs slowly to 15, meaning it is set at 15psi. I also noticed that I mentioned the knock occuring at 10psi, I didn't think that the slow boost and the knock were related, but now that makes sense.
As stated I had a fuel pressure gauge, I had to send it back and am waiting on a new one. It does reach the windshield to sit under the wiper blade so I can watch it (when I get another one).
Answers to questions:
1. No cat... I think it, umm, ran away.
2. How do I check fuel pump voltage?
3. I don't know anything about the Poston's chip... the previous owner put it in there, he buys everything from Poston's. If I were to buy one, I would've chosen a different one. I don't even have a stock one for switching.
4. ignition components work fine.
5. I have looked before and not seen/heard a header exhaust leak. Popular between cyl. 3 & 5, right?

Could a clogged radiator cause knock? My engine gets really hot (hotter than I thought, today was a long day... drove on the Interstate for 15 minutes, over-heated, and spent 2 1/2 hours trying to get back home :mad: ), my ScanMaster showed 280° for coolant temp. Maybe if I can get the temps WAY down with a new radiator, do you all think my knock could go away?
Originally posted by BlackBeauty
My engine gets really hot (hotter than I thought, today was a long day... drove on the Interstate for 15 minutes, over-heated, and spent 2 1/2 hours trying to get back home :mad: ), my ScanMaster showed 280° for coolant temp.

280:eek: That's a big issue dude.. I would advise to fix that before you even drive her again or for that fact before you start it again.
Like the man said big problem.
1. Make sure you have coolant.
2. Check for stuck thermostat . Replace with 160 stat.

I doubt there would be any coolant left if you drove the car at that temp!!. W/ a 16# cap, you would be boiling. I think the rise in boil point is 2* per # of cap pressure.. that would be 212, [assuming sealevel] plus 32* is waaayy below 280!!:eek:
I'd be looking for a leaky head gasket putting hot exhaust gases into the cooling system. w/ that temp, assuming it's accurate, the knok is being caused there.

As for the pump check. Go to the plug at the tank and check across the pump wires. Should be close to the alt output, which should be 13.8 to 14.2 vdc.
Yeah, maybe there wasn't any coolant in the car... cause when I stopped and popped the hood, the coolant was spewing out of the reservoir. And a week ago from yesterday I had the same over-heating problem, we thought it was a stuck open thermostat and replaced it. There was already a 160° in there, and we replaced it with a 195°. When I saw "WE", I mean my step-father and I, he helps me out with car stuff a lot. He is bringing home an OEM radiator tonight.
check to make sure your fan is turning on. i had the same problem over the summer. the car overheated and spit antifreeze through the overflow bottle. was a real PITA especially since i had just detailed the engine the week before.
Thanks for the tip, but the fan does turn on. That's the only way I could eventually make it home in 2 1/2 hours for a 20 minute trip. I would stop, then the fan would run with the car off until the temp got to 190° or so, and that's when I would drive again. The fan also turns on after a couple minutes of driving.
Hope it's not a Headgasket like Chuck thinks.
I would go back with a 160 stat to have the car run cooler.
You can put a thermostat in boiling water to make sure it is opening.
You can run car with the radiator cap off, once it reaches the thermostat temp it will open up and start to cycle.
I hope it's not a head gasket like Chuck thinks! No white smoke from the tailpipes.
I know about how to check a thermostat, but they are so cheap that it's hardly worth testing them. When I installed the 195° thermostat, we saw the coolant flowing.
The reason I got a 195° thermostat is because that's what the original one was. I told my step-dad I was going to get a 160° t-stat since many people on here suggest it, and he told me that if they came with a 195-er, to stick with that, since the car was designed to run at those temps. So I took his word for it.
Originally posted by BlackBeauty
I I told my step-dad I was going to get a 160° t-stat since many people on here suggest it, and he told me that if they came with a 195-er, to stick with that, since the car was designed to run at those temps. So I took his word for it.

For normal street driving in a normal car that would be fine, but does a TR have the same performance as a normal car?:rolleyes:

All jokes aside get the 160, that is the real deal with these cars,
Even the replacment t-stat from GM is a 185.
It may have originally have been designed for a 185 thermo but I bet that Postons chip needs a 160 to work properly.

As far as your boost holding still than climbing, I have a probal cause. My car was doing something similar. Anyways heres why my car was doing that:

When my car started to climb in boost, I would get knock retard. The engine, when timing is being taken out, is not pushing the max amount of exhaust out. This in return is not helping you build boost because the exhaust obviously is not there to turn the turbo. Then as soon as the knock/retard disappears, the exhaust it there and boost starts rising again. So, as soon as you figure out whats causing your knock (be it not enough octane, too much or not enough fuel, or false knock, etc.) this may fix your boost problem. It did mine!!!!

BTW My knock was false. Broken motor mounts!! Your knock sounds like it might be caused by excessive heat.
Thanks for the advice. Since my car is down waiting for a little tiny elbow fitting for the radiator to fit right, I will call Poston's and ask them about the 160° t-stat. I was told the same thing about the chip being designed to run with a 160 from someone at the TR meet a couple weeks ago. I sure do hope this knock goes away. Damn, I just wanna drive my car (been sittin' since Saturday, feels like forever). It wouldn't be so bad at all if we had an extra car, but we have maintained a 1:1 human-to-car ratio for a couple weeks now.
Point of info, the original thermostats in these cars (at least the 86's) was 185 (still got my original), not 195.
I used to try to get rid of all of the part throttle knock too. I found that the only thing I could do is put 100 octane in it. That can get expensive. Then I got the RJC Power Plate. It got rid of ALL of my part throttle knock. I am not going to try to tell you it will make more HP, or even make you able to run more boost, but I will tell you that the Power Plate will take care of all of your part throttle knock. I use 91 octane, so I have it even worse than you. Hope you do not have the other problems that have been discessed cause that would suck. Good luck, ERIC.:)