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Discussion Starter #1
Couple + questions regarding "Knock Sensor". Does it occupy the coolant drain plug next to the starter? I have been reading and studying the issue of 305 vs 350 vs etc... and have not gotten an answer as to sensor for cu in application yes or no. Called JEGS the tech said "Uh what sensor"? I have a GM wiring diagram and "Knock Sensor" is nowhere to be found, yet I find discussions all over the place, does this "Sensor" have another name? I find no missing, cut or cut splices in the wiring loom, yes I have been through the entire wiring system (unwrapped and on the bench). I have located every "Sensor" in my GM wiring diagram and accounted for each wire color by color. Yes I may have missed it and if so what's it color and where does it come from and go to? Tried beer but only helps a little.
 

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Discussion Starter #3
Sandblaster, read that thread, thanks! I have 355cu in/375-415hp Runs terrible, added NEW not rebuilt carb, some new sensors. Black smoke, running rich, poor idle. I'm guessing I need Knock sensor, but which one?
 

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Discussion Starter #4
TCC (Trans), EGR Bleed Control Sol (in front of dist), ACV Air Control Valve, Air Sw Sol (at Air Pump), Carb Air/Fuel Sol (on Carb), O2 Sensor (Down tube Left side), CTS Coolant Temp Sensor (Thermostat Housing), EST Electronic Spark Timing (in Dist), Vac Sensor (Right side top wheel house), and last but not least BarO Sensor (next to ECM).
 

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IIRC
the knock sensors started about 84-85, maybe 85..
V8
its in the block coolant drain on the pass side, low, just above the pan rail, it front of the starter..
V6 was on the intake, I read??


probly not your rich problem
check the CTS and MCS [Carb Air/Fuel Sol (on Carb), ] and the choke..
I wonder if your 375-415hp cam is going to play well with the computer/MAP sensor..
if the cam has some lope? its going to affect the vacuum and the computer/MAP..

.
the ignition module and the pickup coil and the ignition coil is in the dist.
the EST or ESC module is 2"x3" black box, 4or5 wire connector, its usually on the pass wheel well
or on the manifold in front of the dist.
with the EGR solenoid and or MAP sensor which is sometimes on the wheel well, depending on year..


:texas:
 

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Discussion Starter #6
Thanks JJLT1, Good info on the IIRC it's the first I heard that maybe 85 was the year as I am pretty sure that there was no connections I missed.:You_Rock:
 

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I wonder if your 375-415hp cam is going to play well with the computer/MAP sensor..
DITTO. If you built a honest 415HP motor and trying to run it with the stock ECM / prom,, I suspect your going to have a LOOOooooong battle ahead of you.
 

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Discussion Starter #8
Any way to find out if my 1984 El Camino, made in Texas and sold in California had an IIRC "Knock Sensor"? I understand it may not have and my 1984 GM wiring diagram as well as Auto Zones and others that DO NOT show an IIRC in the circuitry. EMC #s maybe? Any other 84 Elkys out there, maybe 1 owner? Look under the hood? Mine was a basket case when it came to wiring/engine swap.
 

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DITTO. If you built a honest 415HP motor and trying to run it with the stock ECM / prom,, I suspect your going to have a LOOOooooong battle ahead of you.
X2,and a battle you will not win by changing a knock sensor.
 

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I looked at my usual reference ( ROCKAUTO). They show Knock Sensors starting in 1983. The 83/84 EST device , based on the picture, is a silver box that looks a lot like the ECM ( Silver), but with only one connector. I would guess that it would be mounted inside the cab, under the dash. Does not look weatherproof.

http://www.rockauto.com/catalog/moreinfo.php?pk=1193386&cc=1042692&jnid=483&jpid=0

Check out the info on Rockauto and see if it helps you .
 

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my 84 choo choo 305 has a knock sensor on the passenger side near the starter just above the oil pan rail. I replaced it 3 months ago because of highway detonation or pinging. Instant fix
 

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Discussion Starter #12
ECM Knock Sensor

Still need to find out about Knock Sensor. My ECM has these markings;

DKZ
*861861 46841577

Service
Number 16041861
Lit Ref Code 1226455

Wires coming from the EST are as follows on both the diagram and physically (except B could be purple or pink);
A = White to Spark Timing Output 423
B = Pink w/White Strip to Dist Ref Pulse Hi Input 430
C = Tan w/Black Strip to Ign Mod Bypass Output 424
D = Black w/Red Strip to Dist Ref Pulse Lo Input 453

Nothing on the wiring diagram about "Knock Sensor"

If it needs one where does it connect and what color wire?
Runs like it's in "Limp Mode" help!

Give me "Old School" anytime!!!

Thanks
Jim
 

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Discussion Starter #15
OK there is no Knock Sensor or any signs that there was one or there should be one in 1984 El Camino. If there is supposed to be one I would like to see the wiring diagram. I cant tell if the cam has lope or not, because it runs like "I might make it home!" and I don't understand if I'm going to have a fight what's it over? I just want the thing to run and Pass SMOG! It seems there are a lot of opinions but no one with fixs or facts. I have now looked at a half a dozen wiring diagrams for 1984 El Camino and not one showed "Knock Sensor", somebody got a different diagram , love to see it! Once I solve this issue, whether I build a new ECM or just figure out what connection(s) I need to make I'll share it with all!
 

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Discussion Starter #16
This is the aluminum box that is behind the passenger kick panel and mine has two connectors that plug in side by side. On my GM 1984 El Camino wiring diagram it is called Electronic Control Module or ECM. So I'm unsure what you are referring to?
 

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Discussion Starter #17
If you are referring to ESC Electronic Spark Control, it is referred to on my diagram as Electronic Spark Timing EST and is located in the Distributor.
 

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This is the aluminum box that is behind the passenger kick panel and mine has two connectors that plug in side by side. On my GM 1984 El Camino wiring diagram it is called Electronic Control Module or ECM. So I'm unsure what you are referring to?
Well my wisecrack reply might be that if you start 4 or 5 more threads on this it may get solved quicker. BUT NIX THAT. Instead lets start with a little review: 1) 355CI, or 350 bored over...Is not and never was an available engine for a 1984 EC. Last year for 350's was 1980, and they did not have ECM's...So engine swap...and 1984 EC diagrams will not match. 2) ? Do you have perhaps a different ECM than an 84 due to engine swap and...3) Limp mode as you describe or 'limp home mode' is a feature of newer electronic transmissions...4L60E and the big heavy 4L80E, Both of which must have required an ECM change to accommodate. And as such a non existent knock sensor might appear as missing.

You have had some good replies from some really good engine guys here, or in one of the other threads. My suggestion is that you take the time to sort out what you do have and how that works together before any further panic over something assumed as missing that may be a non issue.

Just my outside observation and :twocents:. But good luck with the search and fix! :beer:



 

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First of all, stop looking for a knock sensor. I assure you that it is not your issue.

Understand what a knock sensor does, it senses detonation in the engine and signals the ECU to dial back the timing, usually an amount preprogrammed in the ECU. it will not change anything related to mixture - so it has exactly zero chance of solving a rich issue.

Knock sensors usually only come into play at WOT or cruise situations when timing is all in or near to all in, when cruising your vacuum advance will add additional timing, a Chevy small block can cruise with as much as 52 degrees of ignition advance, however with lousy gas this might cause light pinging or surging, the knock sensor allows the ECM to pull timing back.

Similarly at WOT or highly loaded situations like accelerating uphill, with all the timing in and under high load, pinging may occur.

The issue as you have described it is an engine that barely idles, no knock sensor will fix that, simply because at idle there is no load on the engine and just the initial timing, I doubt very much you are experiencing detonation at idle. If you are then you have much bigger issues than a missing sensor.

No, you have some other more fundamental issue going on here.

So first I would recommend, checking the initial timing and setting the carb up as needed to create the highest vacuum signal at idle and work from there.

All that said, If you have indeed a 400+hp small block trying to be run by some ancient OEM ECU, frankly my advice is......... give up now.......it likely cannot handle the increased overlap in your cam, likely cannot provide an adequate timing curve and will not run well at all with the miserably low initial timing settings required for a smog vehicle. Not to mention fail miserably at the smog test.
 
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