LiquidBlue

Hi Guys,

Anyone know what the signal is for a 1989/1990 ECM vapor canister solenoid? Is this a Pulse Width Modulated signal, or simply 5V or 12V? The canister part number is GM 17088067, 1992 parts book shows this to be 1989 only but I'm assuming also for 1990 as well since I have one installed. 1991/1992 is a different part number and 1990 listing is non-existent in the 1992 parts book.

I'm running dynamic EFI software/hardware.

I'm also looking for a way to test the purge solenoid off the car if there is a way.

Thanks,
Jim

RBob

iTrader: (1)

From the ECM it is a PWM signal to ground. IGN+ provides the +12 volts to the solenoid.

Note that GM used both NO and NC solenoids on the 3rd gens. There is an option flag to select/set which one is in use.

To find out which it is, key-off. Then see if the line to the solenoid from the TB can pass air. If so, it is NO.

If air can't pass through then it is a NC solenoid.

Can use +12 volts and ground to the solenoid to activate it. I haven't seen any with a diode on the winding, but it is best to observe polarity. PNK/BLK is the + terminal. And don't place any power or such to the harness connector... Just the solenoid.

RBob.

LiquidBlue

Thanks again for getting back. Will try to test this, running SLP intake, so canister tucked under bumper, making diagnosis a bit more difficult. Hope you don't mind more questions once it all comes apart (again!)

LiquidBlue

Another question for you: I'm wondering if a 1993 4th Gen Solenoid would work? I've done a lot of research and it appears you could take the evap canister from a 1993 and use the 1993 solenoid. The difference is the 1993 canister is just a canister, and the solenoid is mounted remotely. so the canister purge hose runs to the solenoid and then from the solenoid into the throttle body. The catch : does our 3rd GEN PWM signal coming from our ECM operate the 1993 solenoid correctly? Over on 4th gen forums, they are stating the solenoid is PWM controlled. It even looks like our connector would mate up - if not, one even sold (link below)

Normally closed valve, opens at 5.4V
https://wvebrand.com/part-detail/sal...ngs/PV118A.pdf

Connector:
https://wvebrand.com/show-part/1P1479/


https://www.rockauto.com/en/moreinfo...=4936&jsn=1304
https://www.rockauto.com/en/moreinfo...=1234&jsn=1234

http://shbox.com/1/1995_evap.jpg
http://shbox.com/1/emission_hose_routing.jpg
http://shbox.com/1/evap_sol.jpg

Links to wiring diagrams 3rd Gen and 1994 4th Gen (both gens appear to use B+ (12V) to operate the solenoid, both even on same circuit #)

3rd Gen - circuit 428
https://www.thirdgen.org/forums/v6/4...ml#post3801073 (pages A4, A8)

4th Gen (1994) - circuit 428

https://lt1swap.com/all_lt1.htm (from this site)
https://lt1swap.com/pictures/100_1774.jpg
https://lt1swap.com/pictures/100_1783.jpg

4th Gen Service Manual (p, 1803, p2316 TOC, p 2377 EVAP, 2554)
https://www.firebirdnation.com/threa...g-diag.342426/

crazymex83

I feel like maybe it would be helpful for everyone else too but as of June 9, 2022 the vapor canister WVE 4B1222 costs $138 but there are a few for 86 Astro with 4.3L V6 that is similar size but only costs $58, see STANDARD MOTOR PRODUCTS CP1022
More Information for STANDARD MOTOR PRODUCTS CP1022 (rockauto.com)

If you prefer to look up the 1991 Corvette piece at only $51, see WVE 4B1004
More Information for WVE 4B1004 (rockauto.com)

The qty of ports on the Astro says 3 while the Camaro and Corvette canisters say 2