ESC need someone that knows more about ESC system than I do

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SirRobyn0

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Any of you guys have any experience with OEMcats.com I've seen them come up in searches before, but they claim to have a few old stock ACDelco GM pn#16042121 which is what I need. 1 year warranty. I realize it would have to be new old stock, which is fine, I just know nothing about oemcats.com.

It's either that or I'll try the E-bay route. I don't really feel to good about that, but I sure ain't feeling to good about these reman'd units.

I did my short 75 mile trip today and the truck did fine, at least as good as it did before I started changing things up possibly a little better, so I'm sure it'll be just fine tomorrow. Of course the pass was fine today and they are currently reporting snow, hopefully it won't turn into a big deal over night.
 
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AuroraGirl

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Any of you guys have any experience with OEMcats.com I've seen them come up in searches before, but they claim to have a few old stock ACDelco GM pn#16042121 which is what I need. 1 year warranty. I realize it would have to be new old stock, which is fine, I just know nothing about oemcats.com.

It's either that or I'll try the E-bay route. I don't really feel to good about that, but I sure ain't feeling to good about these reman'd units.

I did my short 75 mile trip today and the truck did fine, at least as good as it did before I started changing things up possibly a little better, so I'm sure it'll be just fine tomorrow. Of course the pass was fine today and they are currently reporting snow, hopefully it won't turn into a big deal over night.
reliable but their stock is most likely an aggregate with links to other sources. usually. they also list prices on other vendors often too
 

AuroraGirl

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Poor Engine Performance

1.Disconnect distributor 4 pin connector, connect pins A and C on distributor side of connector with jumper wire, and road test vehicle.
2.If engine performance is still poor, cause is not in ESC system.
If proper engine performance is restored by disconnecting ESC controller from distributor, remove jumper wire, reconnect 4 pin connector and proceed to next step.
3.Disconnect 10 pin connector from ESC controller, inspect terminals for proper contact, shots and opens, repair as needed, then recheck system operation.
4.If problem persists, disconnect 10 pin connector and measure resistance between pins B and K in connector. Reading should be 98-99 Kohms.
5.If resistance is not as specified, disconnect electrical connector from knock sensor and measure resistance between sensor terminal and ground. If resistance is 98-99 ohms, repair wiring between knock sensor and controller. If resistance is not 98-99 Kohms, knock sensor is defective.
6.Reconnect 10 pin connector to controller and measure voltage between pins F and K with ignition on. If voltage reading is less than 11.6 volts repair feed circuit as needed.
7.Set voltmeter on 20 volt AC scale and measure voltage between connector pins H and K with ignition on. If reading is less than .20 volt, inspect system wiring and repair as needed. If reading is greater than .20 volt, ensure all connectors are properly seated, then road test vehicle. If problem persists, replace ESC controller.

also
Engine Detonation

1.Inspect connector and wiring to knock sensor and repair as needed.
2.Connect suitable spark advance tester to engine, run engine until it reaches normal operating temperature and set engine to run at a minimum of 1200 RPM, then observe ignition timing while tapping on exhaust manifold. If ignition timing retards when manifold is tapped, ESC system is operating properly.
3.Stop engine, disconnect 10 pin connector from ESC controller and measure resistance between pins B and K of connector. If resistance is not 98-99 ohms, proceed to step 5.
4.Measure resistance between pins H and K in connector. If resistance is 14-16 ohms, replace controller. If resistance is not 14-16 ohms, repair wiring to controller.
5.Disconnect electrical connector from knock sensor and measure voltage at sensor terminal with engine running at 2000 RPM. If reading is not .08 volt or more, knock sensor is defective.
6.Stop engine. If knock sensor voltage output is satisfactory, check wiring between knock sensor and terminal B of controller and between controller terminal K and ground and repair as needed.

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lastly
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which is your truck by chance
 

AuroraGirl

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NUMBER:86-B-77

GROUP:6D - Engine Electrical

DATE:April, 1986

SUBJECT:SPARK KNOCK (PREIGNITION)

MODELS:1984-85 C, K, G TRUCKS EQUIPPED WITH THE LE9 5.0L, LF3 5.0L, OR LS9 5.7L ENGINE AND ELECTRIC SPARK CONTROL (ESC) FEDERAL EMISSIONS
AND ELECTRONIC SPARK TIMING (EST) CALIFORNIA EMISSIONS.


THIS BULLETIN CANCELS AND SUPERSEDES 86-B-21 (DECEMBER, 1985) ALL COPIES OF WHICH SHOULD BE DESTROYED.

Some 1984-85 vehicles equipped with the LE9 5.0L (VIN Code H), LF3 5.0L (VIN Code F), or LS9 5.7L (VIN Code L) engine may experience detonation (preignition) or poor performance when operating in a loaded condition or pulling a grade. As a result of the preignition, the ESC (Federal) or EST (California) retards the spark timing, and a noticeable reduction in performance may occur. In the event the preignition condition is not corrected by the ESC/EST spark retard, continued operation under these conditions could result in internal
engine damage. To reduce the possibility of this occurrence, the spark plugs should be changed to a colder heat range. When these conditions exist, the original equipment (R44TS) spark plugs should be replaced with R43CTS (P/N 5613810). The correct spark plug gap is .045". Starting with 1986 vehicles, the LE9, LF3, LS9, and LT9 engines are built with the R43CTS spark plugs.
 

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@AuroraGirl Thanks for all that. I knew some of the tests listed in the manual you posted but not all. Sure appreciate that info. I know this module is bad, but being able to test the rest of the system should insure that it isn't something on my truck taking it out is great.

R43CTS has been superseded to CR43TS, they are the same plug only difference is they moved the C designation to the front of the part number. I ran those for sometime until I tried the NGK version which is what I'm running now. Also I prefer .035" for the gap as it idles smoother.

Thanks for all the info. I'm going to try to spend sometime searching out a module tonight. Thanks.
 

AuroraGirl

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@AuroraGirl Thanks for all that. I knew some of the tests listed in the manual you posted but not all. Sure appreciate that info. I know this module is bad, but being able to test the rest of the system should insure that it isn't something on my truck taking it out is great.

R43CTS has been superseded to CR43TS, they are the same plug only difference is they moved the C designation to the front of the part number. I ran those for sometime until I tried the NGK version which is what I'm running now. Also I prefer .035" for the gap as it idles smoother.

Thanks for all the info. I'm going to try to spend sometime searching out a module tonight. Thanks.
.35 gap runs smoother but it also runs longer with less energy
If your timing is advanced and the system pulls it to control knock then I can see an issue possibly with that gap but im just saying what "seems" in my opinion. is your cylinders combustion chambers free of carbon relatively? And could you try .40 (and is the NGK a copper?)
 

AuroraGirl

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also i advise fixing the tip in switch and the vacuum lines for the advance to factory since you now have a diagram and visual showing where it all goes
 

SirRobyn0

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.35 gap runs smoother but it also runs longer with less energy
If your timing is advanced and the system pulls it to control knock then I can see an issue possibly with that gap but im just saying what "seems" in my opinion. is your cylinders combustion chambers free of carbon relatively? And could you try .40 (and is the NGK a copper?)
She's not got the best valve stem seals so there is some oil usage (a quart every 800 - 900 miles). I decarb it occasionally, ACDelco X66A followed by water. It's pretty darn effective, what I'm saying is it shouldn't be bad. (carbon wise). Yes it's a copper plug. I didn't quite get it all out in my post yesterday but the reason for the switch is ACDelco moved plug manufacturing. I can't remember to where to but the plugs now look a little different physically and after a run of ACDelco plugs that would cause a little bit of rough running, well we just run the copper NGK equivalent in all old GM rigs now at the shop and it's worked out well.
also i advise fixing the tip in switch and the vacuum lines for the advance to factory since you now have a diagram and visual showing where it all goes
Tip in switch needs no repairs I fixed a bad electrical connection and it's plumbed correctly.

Agree on the advance system, it would be great to go back to the trapped vacuum system like the factory had it, but that is only there for cold runability, after it warms up it's just getting ported vacuum. The TVS is still available, but the 4 line trapping valve is made of unobtanium, so unless I find a used one somewhere I'm kind of SOL.

My biggest issue right now is getting a module that is good. I've been though 3 reman'd units. I may very well end up ordering from oemcats and seeing what happens. I know Ellie got one off E-bay and that is temping, but I just don't have a lot of faith in used modules. Maybe I should, couldn't be any worse than these reman'd units!

We have used AES Modules to rebuild modules at the shop before, but gee it's not cheap, like starting at $600.00. If it comes to that I'll just carry on without the ESC.
 

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Sorry guys we had the salesman call in at the shop today. Normally the owner would come down to fill in but as luck would have it he's under the weather too. So I'm running double duty.

First thing I researched this a little last night but didn't get to post it, after this I'll respond to you guys.

Ok doing a little bit of reading on the vacuum system for the distributor. Basically it traps and holds vacuum to the advance when cold, using both ported and manifold as a source. Once warmed up some the thermo-valve turns off manifold vacuum, and the trapping system, thus leaving the distributor with ported only as the vacuum source. So with that said the best choice for me and closest to factory would be to just run ported all the time which makes sense based on my observations earlier.
That sounds about like how mine was set up... My vacuum delay valve clogged up and wouldn't bleed off vacuum quickly enough a long time ago, and the TVS was sticking so that the delay valve was in the (vacuum) circuit even when the engine was warm, so I bypassed it and am running straight ported (IIRC) vacuum all the time. I'll eventually get all of those little parts to set everything 100% straight, though it's running really good and hasn't missed a beat yet.

I'm having an ever harder time trusting in a lot of new production and reman parts as time goes on, and decided to go with that used ESC controller on eBay. It was 40 bucks with free shipping, and guaranteed for 90 days. The seller actually has two more of them for sale- here's a link:

Used ESC controller 16042121

I looked inside the one that I purchased, and it had two Delco branded 24 pin microcontrollers, and a handful of discrete resistors and capacitors on a one sided board. No electrolytic caps, so a NOS part should be good to go out of the box, too. I'm fortunate to still have my original GM ignition module... in fact the only ignition part I've had to replace up until now has been the pickup coil, which checked out in 2004.
 

SirRobyn0

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That sounds about like how mine was set up... My vacuum delay valve clogged up and wouldn't bleed off vacuum quickly enough a long time ago, and the TVS was sticking so that the delay valve was in the (vacuum) circuit even when the engine was warm, so I bypassed it and am running straight ported (IIRC) vacuum all the time. I'll eventually get all of those little parts to set everything 100% straight, though it's running really good and hasn't missed a beat yet.

I'm having an ever harder time trusting in a lot of new production and reman parts as time goes on, and decided to go with that used ESC controller on eBay. It was 40 bucks with free shipping, and guaranteed for 90 days. The seller actually has two more of them for sale- here's a link:

Used ESC controller 16042121

I looked inside the one that I purchased, and it had two Delco branded 24 pin microcontrollers, and a handful of discrete resistors and capacitors on a one sided board. No electrolytic caps, so a NOS part should be good to go out of the box, too. I'm fortunate to still have my original GM ignition module... in fact the only ignition part I've had to replace up until now has been the pickup coil, which checked out in 2004.
Thanks for the link. I keep meaning to ask you which seller you used. I looked at that one over the weekend. Almost tempting to grab two of them so I'll have a spare.

As far as the vacuum / delay / trapping system I really don't see why a guy can't just run it on ported. Might loose a little power when cold but at least once the engine has warmed up it switches to ported anyway so it's getting what it is suppose to then at least.

I agree on your assessment of reman parts. I followed you link and went ahead and ordered one. My old distributor was shot, there was no way around that. I could have pulled it apart and rebuilt it, which I may one day do, but for now I will be just keeping it as is, it does fire the truck so it could be used in a pinch. I still have my original ignition module as well, for now that's in the glove box.
 

packman

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It ran fine with it but after replacing it twice and a few years later it developed an intermittent connection issue so I installed an MSC distributor and it has run great for the last 12 years so I would say I was glad to get rid of it.
Hey I’m new here hope to get some answers about my 1984 k10
Here’s my issue .
It will not fire when cranking has zero spark , but if I use a bypass connector I bought online to bypass the ESC it will fire up and run has a rough idle but it will idle and run . I can let it warm up for about 5-10 minutes and reconnect the ESC and it fires right up
I’ve checked the fusible links and put new ones in with the same issue unresolved.
I keep it in the garage so it’s not getting wet from dampness .
Anyone have any ideas of what I should be looking for to fix this issue ?
 

SirRobyn0

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Hey I’m new here hope to get some answers about my 1984 k10
Here’s my issue .
It will not fire when cranking has zero spark , but if I use a bypass connector I bought online to bypass the ESC it will fire up and run has a rough idle but it will idle and run . I can let it warm up for about 5-10 minutes and reconnect the ESC and it fires right up
I’ve checked the fusible links and put new ones in with the same issue unresolved.
I keep it in the garage so it’s not getting wet from dampness .
Anyone have any ideas of what I should be looking for to fix this issue ?
Chris, welcome to the forum. If you bypass the ESC using the connector (I know exactly what your talking about BTW) and it fires up then there really is only one thing. The ESC module, because that's what your bypassing. If you have read the last pages of this thread you'd see a post where I had a similar thing happen. Truck wouldn't start, bypassed the ESC it fired up. I did a couple things to the truck reconnected it, fired it up and drove it for while when it stalled out. Then the problem is getting a good replacement module....
 

SirRobyn0

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I took delivery of my used ESC module today. I'm was impressed with the packaging as it was wrapped in a bubble mailer, then in cardboard then 3 more bubble mailers. The outside housing of the module looks old, but it's got it's GM part# and stickers on it, so it looks like an actual GM module and not a rebuild.

The next few weeks are going to be crazy busy for me. I just got the transmission back for the Jeep from the builder, so that's got to get in and the Jeep and the Jeep back up and running, then I need to drive it a bit. So I doubt I'll get the module in the truck before this weekend, but we'll see. Anyhow my point is I wanted ya'll to know I've got the module, but it might be a bit before I report back on how it does.
 

SirRobyn0

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Well I installed the used ESC module from E-bay this afternoon and it's DOA.

I double checked EVERY thing on the truck and I can see no way that the truck is damaging these units. Then I tapped on the side of the ESC module and it fired up only to stall a minute or so later.

I'm done again. I've easily gotten a days worth of labor into to trying to get the ESC system working. and a couple hundred dollars. I'd love to have a working ESC but without being able to get a good module.....

I've had 5 modules, three remans and two used units. I can't waste anymore time on this.

I'm going to consider options for a moment, but will likely order a Standard Motor Products LX331 Module, which is the module @Ricko1966 suggested and wire it to a switch to ground for a manual retard. My problem with this is it's not automatic and it takes a second to hit a switch no matter how close a guy gets it to his hand. But on the other hand it's better than rattling the motor to death on a long hill with a trailer.
 

SirRobyn0

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It's to bad there isn't a way to get a knock sensor to trip a relay. If that were possible then it could be an automatic retard system....
 

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