theformula

I talked to Ed Wright and with my mods, he said I won't need a custom chip.

He said to go with his stage 2.

Heres my problem. When he custom tunes, he de-sensitizes the knock sensor so it doesnt think the roller rockers I have are fake "knock".

Since this is not a custom chip, the knock sensor will not be de-sensitized. Can't I just disconnect the knock sensor ? Is the knock sensor responsible for anything else besides listening for knock?

Thank you

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91 Formula
305 TPI 5speed
1LE/G92/WS6
K&N, SLP airfoil, ported/polished plenum, March pulleys, TB coolant bypass,Crane AFPR(47psi),Crane Gold 1.6rrs,MSD coil,MSD6AL, Holley 9mm wires,Bosch O2sensor, SLP headers & catback,3:73s w/Auburn posi,180* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.
Street legal with stock throttle body, runners,intake manifold,cam, and heads.

JakeJr

As I understand it, each time the engine is started the ECM sends a signal to the knock sensor to test it. The ECM expects to receive a certain response indicating that all is in order. If it does not get the expected response it sets a code and, I believe reverts to a basic timing map.

Also, unplugging the knock sensor wire is very inadvisable. When the ECM detects knock via the knock sensor, it automatically retards the ignition timing until the knock is abated. This is a major engine safeguard.

There may be different knock sensors that are not as sensative to 'false knock' situations. I don't remember specifically, but one of the later model Vette engines is supposed to have such a sensor.

If you find out let me know.

Hope this helps.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

[This message has been edited by JakeJr (edited January 09, 2001).]

Grim Reaper

Adjusting the knock sensor (and decay rate) through the eprom is the only advisable method to do it.

But WHY do you persist in buying an eprom instead of burning it yourself? Did you know that the stock GM VE tables actually cause your car to run too rich? It did on my car AND I do have some mods. I suspect that this is a "safety" measure put in by GM to ensure that their cars didn't run too lean and detonate. But the cost of this conservatism is a slower car.

While I am sure Ed's "stage 2" chip is better than an ADS or Hypertech, it still will not be as good as a custom eprom you made yourself after you played with it.

Eprom writers would LIKE you to continue to think that it is VERY HARD to burn your own eprom. Trust me, it is not.

Nitro Don

I wired in another knock sensor under the dash,thats grounded.I installed a
on/off/on toggle switch.I switch off the
"working" sensor and switch to the "dummy"
sensor and the cumputer never knows.
Hope this helps.
Nitro Don

JakeJr

Glenn, what would be the approximate cost to get the hardware to burn my own PROMs? Is the hardware available for viewing on the web?

I'd like to take a stab at it.

Thanks,

Jake


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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

Grim Reaper

Jake, go to Traxion's article on PROM burning https://www.thirdgen.org/newdesign/tech/promintro.shtml He has links to various burners, UV Erasers, BIN Editors and a variety of ways to actual program the chip (on GM's Memcal, aftermarket carriers and soldering a ZIF socket to use replaceable chips).

I use the Xtronics Pocket Programmer ($129.00) which uses the parallel port instead of an ISA card, Datarase II UV Eraser ($39) and TunerCat ($69). I also erase and program directly onto the GM Memcal.

I also found, that going to every link that Traxion's article provides and reading all the old posts on the PROM Board from the oldest to the most recent (and setting the topic display to 1 year) answered 99% of every question I had.

You should ask the question on the PROM Board of what would be your best options for your 1986 TPI system. A lot of older MAF systems convert to the 89 6E Bins, but I am not sure if it is possible or what's required for the 1986 system.

This should get you started.