I am going to bypass the KS and install that 3.9k resistor but i am not sure what wattage should I get.

Is it 1/4Watts or 1 or 5 Watts.

Does anybody know?

Thanks

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89Iroc, 305 TPI, WC T5, 3.08 Posi, Headers, Hooker Y-Pipe, 3 inch over the axle, Flowmaster 80, No Cat, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, All free mods,

 

1/4 watt will be super.

 

Just a suggestion make sure you don't have a a 100k one. My 89's was 100k.

 

Why do you want to bypass the Knock Sensor? What advantage would that give you?

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1987 IROC,305 TPI Slush box G80,G92,143K+:Mint condition,K&N Filters, ADS Superchip, Stock Exhaust, Virgin Engine and transmission.

1968 SS Camaro, 350 built and shaved, Holley 750 Dual line double pumper, TH-400, 3.73's

Two other Thrid Gen Camaro's for parts ('84Z and '85Z TPI)

 

I want to bypass the KS because i think that it mighnt be getting false reading.

My car seems inconsistant in performance. Somedays it fells like it has 100hp more other days feels weaker.

So i do not think that the detonation is an issue here. I am running low temp thermostat, got the fuel pressure set higher, live in a cold climate and got the EGR hooked up.



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89Iroc, 305 TPI, WC T5, 3.08 Posi, Headers, Hooker Y-Pipe, 3 inch over the axle, Flowmaster 80, No Cat, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, All free mods,

 

If you feel it's pulling the timing out, it probably is. I bypassed mine and it was different car. Twice the power. The fun didn't last though. I ripped 8 teeth off the ring gear in the rear.

 

Get a scanner and find out what is really going on. If you want to keep modding your car and solve any problems that come up, you have to monitor what's going on.

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'87 Formula WS6 - ZZ4 Crate TPI, Scroggin-Dickey ported heads, LT4 hot cam, 1.6RR, Accel runners, Accel base, ported plenum, Edelbrock 58mm TB, Crane Fireball ignition, SLP cold air, SLP 1 5/8 headers, !cat, Summit exhaust cutout, Walbro 255, Koni yellows, Hotchkis panhard & LCA's, 9 bolt w/3.27's.

 

I notice some of the LS1 guys bypassing the knock sensor. They have a set up that uses a certain ohm resistor, and it is triggered via a toggle switch. They run this only at the track with higher octane gasoline. They "claim" .1 - .15 - can anyone shed some light on this? Would this be worth the time/money for a track-only mod?

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1986 IROC, fully loaded, Mini Ram'd 383, Art Carr 700R4, Accel DFI, 12 bolt rear, etc, etc......

 

Well, you don't necessarily need race gas, but if you don't have a scanner then bypassing the KS is the only way to verify that you aren't getting knock reatrd and loosing performance, which could otherwise drive you nuts in your tuning.
So yes, if you don't have a scanner, bypassing the KS can be a useful mod at the track providing you listen for detonation and don't try to blow it up.

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Ed Maher - Moderator @ The TPI & Carb Boards
92 Z28 Convertible - Quasar blue / Tan top
305 TPI A4 2.73 - 14.7 @ 93.6
Stock except ported plenum and dual cats
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

a 3500-3900ohm resistor 1/4watt is what i use
to bypass the KS. solder a ground alligator
clip on one side and old KS connector pin on
the other side. like ed says, if the scanner
isnt available, then the resistor is a lucky
tool to use.
airdeano

 

Um, Could you please describe in more detail how to install this resistor? I'm very interested in trying this on my Camaro.

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1987 IROC,305 TPI Slush box G80,G92,143K+:Mint condition,K&N Filters, ADS Superchip, Stock Exhaust, Virgin Engine and transmission.

1968 SS Camaro, 350 built and shaved, Holley 750 Dual line double pumper, TH-400, 3.73's

Two other Thrid Gen Camaro's for parts ('84Z and '85Z TPI)

 

Yea, um here is my thoughts on this one. IF your knock sesor is getting a false reading the replace it. It only pulls timing out when harmful detonation occurs.

Im sorry to rip on some people like this, but the day in age of finding ways to bypass the computer controls are over. There is enough softwares and cheap lap tops out there to tune these cars properly. You NEED the knock sensor. IT protects your engine. YOu can tune from it and the O2 sensor for the total amount of timing and fuel you need and so on. Your car will be much stronger if its in proper tune. Simple as that.
KEEP THE KNOCK SENSOR IN THE LOOP AND FIND OUT WHAT THE TRUE PROBLEM IS.
Yea I mean if you take the KNock sensor out of a turbo car you can put unbelievable amounts of boost to it, but your just going to blow the motor up.

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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

First of I'd just like to make a correction in saying that I believe these people are talkin' about bypassing the KS as a "Diagnostic" tool, not just leaving it bypassed forever. I could be wrong.

Second, laptops aren't really that cheap for someone who lives on a limited budget.

 

Um well I got a Pentium 100mHz laptop for about $100.
Check out ebay they are cheap. Almost any computer can run Diacom.

 

Where on earth do you get one of the 3900 ohm 1/4 watt resistors? I tried 5 radio shacks, they thought I was crazy asking for that and said all they have is 3300 then it jumps up to 4700 ohms. I tried several hobby shops too. No luck. I wanted one today because I am parking my car for winter tomorrow, but it looks like I am SOL for this year. Dang it.

 

I just unhooked the wire off my knock sensor and the engine runs fine. I'm going to trash the sensor eventually and put in a plug. The sensor is not making my car any faster so it needs to go.



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1986 Iroc 305 small block chevy getting modded now for speed

 

Look for a 3.9 not 3900 . That probably confused them. I didn't ask. I just walked back and picked it out next to the radio stuff.



[This message has been edited by IROC315 (edited November 04, 2001).]

 

If your going to start doing things like this you might consider learning how to do your own chips.
Unless your really good with reading plugs, the K/S will do a better job at detecting knock then you can.
When you get a slightly lousy tank of gas you can run in an area of tip in detonation, and never hear the problem, and not do your engine any good.
Yes, false triggering of the sensor can be a pain to find, but there might be a real problem causing it, ie bad Alternator bearing, bad serpentine belt, etc..
Rather then just screwing it into the block on the marine applications, GM uses a 45d male to female pipe fitting to desensitize it.
Normal disclaimers, yada yada...

 

my car was running great without the sensor hooked up...
up until last night when i parked it to start ripping the tpi all off it.
The IAC along with a bunch of other stuff has also been unhooked for a while and the car was running better than i ever remember it doing. Idle was perfectly steady no matter what... never went up and down.

I'm so psyched about getting this crap off my baby!!


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1986 Iroc 305 small block chevy getting modded now for speed

 

305sbc,
if you indeed have disconnected the knock
sensor, your system is not in closed loop.
without the KS inline, the computer will not advance the timing in a normal fashion.
basically your running in a lock down timing.
your initial timing plus 8-10*. fuel trim is
locked at 128. yeah id be pretty po'ed if the
system didnt work either.. ever try to fix it?
if you do remove the TPI, what do you want for the TPI w/distributor, minus the harness
and computer?
airdeano

 

You're wrong about closed loop and the timing. On Diacom I could see it going closed and advancing same as always, just with never any knocks or retard. Maybe you're thinking of a newer year or something.
All the hard TPI parts are already gone & sold. All I have left is the ECM and Harness. I just pulled the gas tank and getting ready to start porting my heads.



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1986 Iroc 305 small block chevy getting modded now for speed

 

Dude your so full of it I am goign to have to put on my wader boots. There is now way your car will idle right or advance proper timing with everything disconnected.

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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

I would just like to let everyone know that I just gained 4 tenths and 4 mph bypassing my KS. Not bad for 27 cents. This is not a permanent fix, it just was wonderful to pinpoint a problem with it. Hell might freeze over pretty quick, cause my car is actually starting to run right

 

All you need is resonation from adding something like headers to recieve false knock. This occurs all the time. For LT1 cars, they can just buy a LT4 knock module which isnt as sensative so it will not pick up the false knock, but work under real detonation. Same concept as the resistor mod.

After adding headers, I received 10 degrees of false knock, and the car fell on its face running slower than without the new exhaust.. Once I figured out the problem and corrected it, I gained over 4 mph and .5 tenths from he header install and off road pipe. False knock was holding me back.

Desensatising the knock sensor to get rid of false knock will work wonders if you dont desensatize it to the point where it makes the sensor non functional. You really should use a scanner to confirm that it is actually false knock you are recieving..

This will not throw trouble codes and cause the ecm to go into open loop.

 

kyle your post is such a big help to danielek. you must be a tpi wiz along with a couple others on here. i wish you guys weren't allowed to post total crap on here like that. some new people might just be fooled into taking your advice or letting you get away with insulting them because they are new.
i only posted what i knew for fact and did not try to insult anybody. i don't think you should be throwing rocks. it doesn't help anybody.




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1986 Iroc 305 small block chevy getting modded now for speed

 

This thread is closed, the answer has long since been stated.