Running with 1 knock sensor?

[oldskool-nick]

I decided to make a new thread since the other one was cluttered with my other problems. This is the only thing keepng me from installing my engine, so I'm really hoping I can get some kind of answer.

Basically, I am still using my 7m-ge block, but I swapped the electronics and wiring harness over from a 7m-gte. The 7m-ge has 1 knock sensor and the 7m-gte has 2. My block has the bosses for the other 2 sensors, but they are not drilled and tapped.

What would happen if I just leave one of the k/s connectors unplugged? Would the ecu still be able to function properly with only 1 knock sensor? Will the car run at all? Thanks,

-Nick

 

[mickyg]

Take this with a grain of salt, but from what I understand, the extra knock sensor is basically for extra sensitivity. One will pick up noise from a central spot (which is where it is on the GE) but two is going to pick up a bit more, especially if it's at the front and back (as in on the GTE block). KSs are just tuned microphones and unless the ECU is "looking" for a specific load from 2 sensors or if it's got two circuits, it's probably going to be fine with just one sensor. I would expect that the sensitivity of the ECU to the knock sensor output is possibly a bit toned down on the GTE ECU but that may not be correct. If all of what I've just said is correct, you will not hurt anything by running one sensor. However, you do lose some sensitivity and the ECU's ability to change engine parameters if there are problems.

So to summarize:
Will the engine start with one sensor? I'd say yes, no problem
Will there be a problem with the ECU seeing only one? Look at the ECU diag output codes and see if there's one for "front KS" and "rear KS" if not, shouldn't be a problem.

I see your dilemna though, if you get it all back together and there's an issue, then you've got to get it out again. Check that diag code list to see if there's an answer there and wait for more feedback from others before proceeding.

Just my 2 cents!

 

[amd_hcds]

I say while the engine is out drill the 2 places in the na block for the 2 gte ks's and place them

 

[supradan22]

If I remeber correctly your able to take both the connecters and wire it up to the one sensor on the GE block and GTE ecu will act as if they were two of em.

 

[supra90turbo]

eh... why not just tap the two other KS holes?

 

[oldskool-nick]

Thanks for the help guys!

Micky: I checked and there is only 1 diagnostic code for the knock sensor (code 52) so things may be looking up. Also, there is only one pin on the ecu pinout diagram for the knock sensor, not 2 pins. I don't really understand why, but I'm glad. And I was thinking the same thing about losing some sensitivity, which hopefully won't be a huge problem since I will be using the MAFT-Pro to adjust most of the parameters....except timing

amd: I would, and that would be the best way, but I have never drilled and tapped cast iron before. It would probably take me like 4 hours just to drill one hole. Plus, with my luck I'd probably end up cracking the block somehow and that would ruin everthing.

If I remeber correctly your able to take both the connecters and wire it up to the one sensor on the GE block and GTE ecu will act as if they were two of em.

That is exactly what I wanted to hear. I'm going to do a little more research and hopefully find someone that has done this, but that is probably what I'll end up doing.

Thanks again everyone!

-Nick

 

[oldskool-nick]

Well, I looked at that diagram again, and it looks like there are 2 pins on the ecu for the knock sensors. There is KNK1, KNK2, and a KS pin. So I would have to wire them together to complete the circuit. ...Unless KNK stands for something else, which I doubt.

this is the best daigram I could find:

 

[oldskool-nick]

Have any of you sucessfully drilled and tapped the block before? Like I said, that is definatley the best way, but I've never done it.

 

[shaeff]

on my n/a block, the holes are already tapped if i remember correctly. you might wanna check that.

-shaeff

 

[oldskool-nick]

on my n/a block, the holes are already tapped if i remember correctly. you might wanna check that.

-shaeff

My block has the bosses for the other 2 sensors, but they are not drilled and tapped.

What year is your block from? I think that all of them after 1986.5 were drilled and tapped in all 3 holes. I have a cracked '88 GTE block and the unused boss is tapped, but unfortunatley, these are not. Believe me, that was the first thing I checked.

 

[amd_hcds]

I think all n\a blocks have the places for the 2 gte knock sensors but they aren't driller or tapped?

 

[oldskool-nick]

Well, I drilled and tapped the two holes and installed the knock sensors. I thought it would be a lot harder than it was. I bought a new drill bit set for hard metals and started with a really small bit and worked my way up. It didn't take long at all, and now it's done right.

Thanks for all the help once again!

 

[Stretch]

Run all 3 knock sensors, then you'll be covered for any spec of knock and use the HKS knock detector thing to read all 3.:icon_bigg
eric

 

[Nick M]

Well, I drilled and tapped the two holes and installed the knock sensors. I thought it would be a lot harder than it was. I bought a new drill bit set for hard metals and started with a really small bit and worked my way up. It didn't take long at all, and now it's done right.

Thanks for all the help once again!

+1 for somebody doing something right and not "what is the cheapest way, or do I have to" shit.