knock sensors on LT1 ?

[skandolis]

Hey guys, just came into a 95 "bubble" caprice for a swap project. the original engine was a l99 (4.3) at some point it had an aluminum head lt1 swapped in
(then abandoned forever, looks like its been sitting a number of years.) anyways after a lot of cussing and alcohol it fired up today.(and ran badly) the only code was for knock sensor circuit, so i crawled under and yup two plugs for knock sensors and only one sensor. i assume the motor is from a F body and only ran one sensor, but the question is how can i make it happy with the one that is on it? Looking at the bin in Tunerpro, I can't find a flag or anything to indicate a difference. google seems to be no help except to tell me what i already know, The F body had one sensor and the B body had two....... is this just programming or do i need to pony up and get a pair of sensors? any help appreciated, thanks much.

[lionelhutz]

Measure the resistance of the knock sensor. Typically, a single knock sensor is 4k ohms and parallel knock sensors are 8k ohms. Having a single 8k ohm knock sensor in the LT1 could explain your problem.

[skandolis]

Turns out the sensor in the block was dead. no resistance............ i assume this would be measured from the pole to the body of the sensor? i ordered up a pair of sensors for the iron head lt1, orielly's will deliver them in the morning. orielly's is showing the same part number for the l99 and the lt1 in the caprice, and the fbody........from further research, it seems the difference is in the knock module in the pcm. (according to http://lt1swap.com/lt1_bcc.htm ) i appreciate the response, tomorrow evening i get to find out what else is wrong with this thing........

[lionelhutz]

Yes, measure from the pin to the base of the sensor.

Did you check the p/n of the knock module that you currently have?

Now you have me curious. I have an old B-body LT1 harness and I'll have to try and pull it out of the box and see how many knock sensor connectors are on it.