replacement ECM (or ECU?) for my '95 Wagon

[billmorrow]

they get water/coolant/oil inside
the reluctor works loose and gets damaged - may also damage the optical sensor
optic sensor fails
bearing wears out
C&R wears out
etc...

depending on the damage done and parts availability, you may need to replace the opti.

The fact your mechanic misdiagnosed that code16 and replaced the ECM is a red flag to me.
Friend of mine, had been working as a mechanic for 15+ years, had never seen an LT1 before and called me up to help him trouble shoot one. He also 'fired the parts cannon' but didn't fix the problem.
I'm pretty jaded when it comes to repair shops (past experience) and prefer to do as much of my own maintenance as possible.

"fired the parts cannon"..?! 🙂 now THAT is a good description of what happens at mercedes dealerships..
reluctor, C&R..??!! now you are firing the word cannon at me.. these are all new words.. look at my avatar, i am living in the '50's and '60's when all that was required was a pair of pliers and a screwdriver, the fancy phillips type.. or at least trying to..
thanks for your help and advice, having operated an online forum since '95 when 2 of my buicks were new, i know how helpful many voices can be in troubleshooting car or laptop computer issues and gremlins (not the nash car)..

re. the ECM, i concurred and got one for $50 so it is not a big thing.. and it might come in handy should the NORKS, iranians or china nuke us into the 17th century..

i am on a learning curve here and what i read about code 16 was a bit confusing and did not point to the optispark but to wiring issues... at lease that is how i read it..

off to the mechanic shop now with more info for them..

again, thanks..

 

[Dirtybob]

C&R is short hand for cap and rotor
having a spare pcm isn't a bad thing

the optic sensor reads the cutouts on the reluctor wheel, the inner/uneven ones (low resolution) and the 360 evenly spaced/sized ones around the outside edge (high resolution).

 

[billmorrow]

thanks bob..
that is a great picture..
i'm going to steal it..
the screw the mechanic broke off is a very small one.. in about the 2:50 & 8:50 positions on the reluctor wheel..
i am getting, from this thread, that the optical sensor is a critical component and that it should be saved from any unit that is being tossed..
i the mechanic said he is using OS units made by "standard"..?
so my next question is what are the best OS units, rebuilt or newly non-GM built replacement OS units..?
AND, just to ask, i found a rebuilt AC delco for about $400.. is that a deal..?

thanks for the education.. 🙂

 

[Dirtybob]

The OEM optis used mitsubishi sensors - those are the keepers. They are easy to ID because it will have the mitsubishi logo on the sensor.
A broken screw on the reluctor wheel is a problem...
Standard is just another parts house unit. I would disassemble/inspect (put locktite on the reluctor screws while it's apart) and make sure it seals.
I can't speak to 'best units' or prices (not currently looking for an opti plus everything has been getting more expensive of late).
I stole that pic from here: Today, I Replaced JUST the Optical Sensor - Optispark - LS1TECH - Camaro and Firebird Forum Discussion

more info here: Tore down some optispark sensors today - LS1TECH - Camaro and Firebird Forum Discussion

 

[billmorrow]

placed an order at rock auto for a rebuilt GM optispark.. later it was cancelled, no stock.. my mechanic shop ordered a standard optispark (OS) from a local parts store, it was delivered, i took a look at it and all that was there were some plastic parts, rotor, dist. cap etc. but no little wheel or sensors.. the shop owner will find out from the parts house why that is all that is there..
my white car is still down with the OS apart, see pix..
you can see were the broken screw is..
i am not at all sure exactly WHAT i would get if i order another from rock auto.. ALL the parts or just plastic parts..?!

 

[-Regal-]

Would pass on what your mechanic did. Distributor is not a part I would EVER take a chance on like that. One mechanic I know threw out the factory distributor from a family members Camaro and put in some locally obtained shit and it's never ran the same again. Still pissed he'd take advantage of my family like that to make a few bucks.

 

[billmorrow]

little choice now, car is there, won't go anyplace until it is running..
these are not bad guys just maybe unfamiliar with these strange optispark things.. i know i am, but my learning curve is sloping upward..
my '92 had a leaking water pump they fixed, good that one has a more classic distributor on the back side of the engine..
that car runs, so far, like a champ..

 

[HotZ28]

A lot of optispark info in the link below.

Search results for query: optispark

buickforums.com

 

[-Regal-]

Ask for the old one back and rebuild it as optimal (NOS) parts become available. You're going to need it.

 

[billmorrow]

A lot of optispark info in the link below.

Search results for query: optispark

buickforums.com

thanks for the link but the top 10 or so are this thread.. 🙂

 

[billmorrow]

Ask for the old one back and rebuild it as optimal (NOS) parts become available. You're going to need it.

i always keep the old parts from most everything.. 🙂
but today i looked around the shop and located the reluctor wheel and it is wrinkled so most likely unusable..
but it will qualify as a core for the NAPA OS..
anyway, i just ordered a rebuilt one from NAPA and might also get one i see on ebay that they SAY is new, but i'll bet not new from GM..
i just need to get these two '95's back running so i can sell one and keep the '92 and the blue '95..
thank you all for the help.. 🙂

 

[HotZ28]

thanks for the link but the top 10 or so are this thread.. 🙂

Dig deeper into the thread. A lot of info in the archives.

 

[billmorrow]

I don't know why anyone would replace it unless they had a NOS factory one in box. Cap and rotor replacement is far better than putting an entire junk one in. When Cardone sent me a foreign made distributor for my Cadillac I refused to install it and they refunded my money. It's because everyone else doesn't do this that we have such junky parts in the first place.

SO! what is to be done if no NOS GM optispark..?
the guy working on the white '95 says he has the original GM parts for the optispark he is working on now..
had no time today to go visit that shop, but when i do i will verify GM parts..
the other blue '95 wagon's issues are now pointing to the optispark (see above in this thread) so now what.. if i need a rebuilt optispark what to do and how can I tell the difference between a good vs. a bad optispark..? 🙂
what goes wrong with these optisparks that would require a whole new replacement and what ever happened to "new points, condenser, cap and rotor"..?

started this reply saturday, just now coming back to finish

meanwhile i ordered a rebuilt OS from NAPA, due to arrive tuesday..
found a chinese rebuild OS on flebay for $149, might get that one too and compare BUT before i order it i'll find out the maker of the optical sensor.. he DOES guarantee them for 3+ years but if it fails i doubt he will pay for the R&R of the water pump..

learning a lot here.. beginning to think the pre-LT1 engine cars are the better cars to get.. 🙂

 

[Dirtybob]

learning a lot here.. beginning to think the pre-LT1 engine cars are the better cars to get.. 🙂

I hear you. I'm still debating throwing a carb on one of my LT1s. Also getting lazy in my old age and prefer cavernous & un-cluttered engine bays.
FWIW while you are learning about the opti, if you also learn how to read data logs (need a communication cable & laptop, software is free) then LT1s aren't so difficult.

 

[billmorrow]

I hear you. I'm still debating throwing a carb on one of my LT1s. Also getting lazy in my old age and prefer cavernous & un-cluttered engine bays.
FWIW while you are learning about the opti, if you also learn how to read data logs (need a communication cable & laptop, software is free) then LT1s aren't so difficult.

let us NOT drift to carbs, please, just having found what i hope to be a good rebuilt carter AFB for my '59 cadillac.. 🙂
re. data logs, i CAN read.. and i have many thinkpad computers.. just where can i learn about the data cable..? is it a serial (2,3,7&20) cable or a serial buss cable..? and where to plug it in on a '95 which has the OBD1 and no data port to the ECM.. i see this: INNOVA 3123 GM OBD1 Code Reader for $32 at amazon..? same thing..? nevertheless, the error code is 16 which points to the distributor which i am getting from the climate control when pushing the right buttons..

 

[Dirtybob]

I purchased a cable here: OBD Diagnostics ('95 should be a 12 pin diagnostic port - easy enough to verify)

is it a serial (2,3,7&20) cable or a serial buss cable..?

that's above my paygrade but I'm no stranger to carburetors 😛

I use eehack for logging Tuning Software – fbodytech
scan9495 is another free logger but was very buggy with my laptop, others report no problems YMMV.

Lots more info on gearhead-efi.com

 

[billmorrow]

I purchased a cable here: OBD Diagnostics ('95 should be a 12 pin diagnostic port - easy enough to verify)

that's above my paygrade but I'm no stranger to carburetors 😛

I use eehack for logging Tuning Software – fbodytech
scan9495 is another free logger but was very buggy with my laptop, others report no problems YMMV.

Lots more info on gearhead-efi.com

thank YOU for the link to OBD diagnostics..
just FWIW the 2,3 7 & 20 is a serial port of the type they talk about on the OBD web site referring to ancient laptops..
where 2 is send, 3 is receive, 7 is common and 20 is ground.. 7 & 20 are tied together so all that is really needed is 2,3&7..
here is a link that shows it..

serial pinout db9 at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

all this is from the prehistoric days of PC computers and i was there when it all was going down..

since thinkpad laptops is what i do i have so many i recently sold 26+ and more keep dropping out of the woodwork so that is not the issue..
and a really good thinkpad is cheap if you need one..

so thank you for the link to OBD diag.. 🙂
i'll crawl under my buick dash boards at the shop tomorrow when i pick up the optispark at the local NAPA store to see which plug is present..

since we are on the topic how do i pull codes from my '92 buick RM..?

 

[2007LucerneCXL]

This may be worth looking at as it appears you have the PC knowledge that it would make sense.

OBD Diagnostics

aldlcable.com

 

[Dirtybob]

A 92 roadmaster should be standard obd1 protocol. i.e. the paperclip trick should work, as well as something like tunerpro with a (12 pin?) cable.
94&95 LT1 cars had the 8051 pcm and sometimes are referred to as obd1.5

 

[billmorrow]

This may be worth looking at as it appears you have the PC knowledge that it would make sense.

OBD Diagnostics

aldlcable.com

some small PC knowledge from the days pre-PC in the early/mid '70's when one had to build your own.. looking at the OBD diag site it seems they are focused on serious people who do it either as a vocation or avocation.. either way the cost is above my comfort level for something i would use only a few times and i would be way out of my depth modding engine performance via the ECM..
i purchased a NAPA OS for about $175+$100 core chare AND ordered another from advance auto, a very expensive one at about $350+ so i'll report back the results for both cars currently at the shop..