The Fiero EGR solenoids have been discontinued for quite some time but there is an easy and economical replacement available that is used on the early Cherolet S-10's and it is available. Its Standard P/N VS12. The mounting and physical dimensions are slightly different but the function is exactly the same. They can be purchased for $18.68 on RockAuto
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I have been told that GM PN 10068570 / 10137639 Delco 214365 Napa 22294 will work in place of the original but do not mount the same. I think this also may require a new updated pigtail for the plug. I think that would be Delco PT1136. Its commenly known as VS6 and is what was on the 2.8lv6 on late 80s early 90s S10s. I have not been able to verify this info. However if im not mistaken the VS12 is only a 2 pin connector it does not have the feedback for the ECU to say its open or closed this will cause a code to throw.
[This message has been edited by skywurz (edited 07-11-2021).]
I have been told that GM PN 10068570 / 10137639 Delco 214365 Napa 22294 will work in place of the original but do not mount the same. I think this also may require a new updated pigtail for the plug. I think that would be Delco PT1136. Its commonly known as VS6 and is what was on the 2.8lv6 on late 80s early 90s S10s. I have not been able to verify this info. However if im not mistaken the VS12 is only a 2 pin connector it does not have the feedback for the ECU to say its open or closed this will cause a code to throw.
The last time I did this EGR replacement was about 10 years ago and the info was from memory. I just recall that we used an S-10 EGR solenoid. The Fiero EGR solenoid uses a 4 pin connector so if the VS12 only has two then it is not the correct part number. Two of the four pins are used to activate the EGR valve and two act as a control switch that would activate in case of failure. The VS 6 is a four pin connector so that's probably it. Its just uses a different 4 pin connector that will be needed. I'll try to get you some more specific info tomorrow.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 07-12-2021).]
Im interested to see the results for a cheap egr solenoid replacement. my egr solenoid seems to be working on and off now, so its probably close to death. id honestly rather delete the egr but just fixing it seems easier if theres a solenoid i could buy.
Im interested to see the results for a cheap egr solenoid replacement. my egr solenoid seems to be working on and off now, so its probably close to death. id honestly rather delete the egr but just fixing it seems easier if theres a solenoid i could buy.
Same here! I have been dreading the day I would need to rebuild my 35 year old EGR solenoid but if I could get a brand new $20 then that would be fantastic!
I have news for you. The VS6 isn't $20. Rock Auto sells it for $70.79. Still, if it works, it's worth it. That's from a 88 S10 2.8 engine.
The VS6 solenoid is used on a wide variety of GM vehicles. Looking at the 90 S10, a video came up showing the replacement on a 7.4L V8. The one I've had on the shelf for years is marked for an 86 or 87 Buick Grand National Turbo.
For my part, the area I would have trouble with converting is that the terminals aren't marked with numbers or letters, so an S10 would need to be present during the conversion.
[This message has been edited by fierofool (edited 07-14-2021).]
I have news for you. The VS6 isn't $20. Rock Auto sells it for $70.79. Still, if it works, it's worth it. That's from a 88 S10 2.8 engine.
The VS6 solenoid is used on a wide variety of GM vehicles. Looking at the 90 S10, a video came up showing the replacement on a 7.4L V8. The one I've had on the shelf for years is marked for an 86 or 87 Buick Grand National Turbo.
For my part, the area I would have trouble with converting is that the terminals aren't marked with numbers or letters, so an S10 would need to be present during the conversion.
Correct the VS6 is in fact $70 and will require a new connector but the junkyards may give you the whole deal for $10. As for the hookup I guess we will have to dig into the manuals to see which pins go where. I did one years back but didn't save the notes. As the Fiero EGR solenoid has long been discontinued, you don't see many in the salvage yards anymore and an option is needed. As for cost I believe that the Fieros EGR solenoid cost was $168 before they were discontinued. I believe that the valve uses a PWM signal to operate and with constant on-off use, this part may become more routine maintenance moving forward.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Dennis, I would be interested in trying the conversion on my 86SE. It's kind of my guinea pig for new stuff. Maybe schematics for the S10 can be found online. I'll do some searching.
If Dennis already has this working on his car for 10 years he should be able to tell us the pinout as is currently on his car
Did this on a customer car not mine years back. Misplaced the notes and my 60* V6 that has a good solenoid has been in mothballs for quite a while. The pin outs on the Fiero EGR solenoid are : A. Ignition 12V B PWM ground signal supplied by the ECM C. vacuum switch signal that sets the trouble code D. Ground Is that what you have found? They should be exactly the same on the later GM EGR solenoids. Just got to find the S-10 pin diagram and confirm. BTW, are you ready to try the conversion? I understand that California will not allow it.
[This message has been edited by Dennis LaGrua (edited 07-14-2021).]
BTW, are you ready to try the conversion? I understand that California will not allow it.
As long as it looks stock and functions as stock they don't care. The techs don't know what a stock one looks like. If i spray paint my stock solenoid chrome it would probably instantly fail. Plus the solenoid is not part of the inspection list just the valve. The computer is supposed to tattle on a bad solenoid via check engine light. Check engine light is instant fail.
In a private conversation, Dennis provided me with the wiring colors. I looked at my replacement EGR solenoid which really came from an 86 or 87 Grand National Turbo, and the terminal markings can't be seen unless the cover for the filter is removed. They are the same.
The only place I could find the 4 pin S10 solenoid harness was at Rock Auto. I plan to depin my Fiero harness and plug it into the S10 harness plug.
As long as it looks stock and functions as stock they don't care. The techs don't know what a stock one looks like. If i spray paint my stock solenoid chrome it would probably instantly fail. Plus the solenoid is not part of the inspection list just the valve. The computer is supposed to tattle on a bad solenoid via check engine light. Check engine light is instant fail.
Just in my initial appraisal, I think the replacement could be bolted to the original bracket with its existing bolt. It's pretty much confgured for connections like our original, so nothing should be seriously out of place.
For a check engine light at testing, try a similar tactic my father in law used when he was trading for a new truck. His old car had a bad transmission that would only slip once it got warmed up really good. He parked it on the street near the dealership on the night before. Next day his son took him down and he drove the car into the dealership. Their test drive was uneventful and he made the trade for the new truck.
Just clear the ECM before driving into the test center since EGR codes aren't set except during highway driving speeds.
In a private conversation, Dennis provided me with the wiring colors. I looked at my replacement EGR solenoid which really came from an 86 or 87 Grand National Turbo, and the terminal markings can't be seen unless the cover for the filter is removed. They are the same.
The only place I could find the 4 pin S10 solenoid harness was at Rock Auto. I plan to depin my Fiero harness and plug it into the S10 harness plug.
It is logical that the marking in the connectors on the VS6 A.B.C.D will correspond to the exact A.B.C.D. pin assignments on the Fiero EGR solenoid but I don't recall. I will try to recheck to confirm as this solenoid was used on many models of 1988-1995 Chevrolet and GM trucks. It was also used on the 89-90 Sunbird,90-92 Transport and 89 Grand Am according to Rock Auto. In essence the four connections are just 12 V power, ECM/PWM signal, fault code switch and ground.
It is logical that the marking in the connectors on the VS6 A.B.C.D will correspond to the exact A.B.C.D. pin assignments on the Fiero EGR solenoid but I don't recall. I will try to recheck to confirm as this solenoid was used on many models of 1988-1995 Chevrolet and GM trucks. It was also used on the 89-90 Sunbird,90-92 Transport and 89 Grand Am according to Rock Auto. In essence the four connections are just 12 V power, ECM/PWM signal, fault code switch and ground.
I've got a set of manuals for a 92 S10, somewhere. If I can find them, I'll see what I can figure out. (That's a big "if". They were packed up when we moved.)
I've got a set of manuals for a 92 S10, somewhere. If I can find them, I'll see what I can figure out. (That's a big "if". They were packed up when we moved.)
Note important edit. Know the feeling. Just looked it up in an old 1993 Silverado manual. The install there follows the exact same wiring marking sequence A.B.C.D. on the VS6 EGR solenoid as on the Fiero unit except for C the fault switch which is left open. It may not set a code or it may require hooking to pin D ground to eliminate the code from setting. I would leave it open to start. I believe Fierofool is going to try it. The bottom line is that if we wish to keep stock 2.8L EGR operation, there may not be any other replacement alternative available.
[This message has been edited by Dennis LaGrua (edited 07-18-2021).]
Great thread on an aging component that has become more problematic over time. Funny this would come up a few days ago, because I started getting Code 32 a month ago after EGR tube fix. So I took solenoid off, checked connections, new hose, smacked it around a few times, and the CEL never came back on so I thought I fixed it..... until it came back on today! So I blame this thread, lol
[This message has been edited by Skybax (edited 07-15-2021).]
Great thread on an aging component that has become more problematic over time. Funny this would come up a few days ago, because I started getting Code 32 a month ago after EGR tube fix. So I took solenoid off, checked connections, new hose, smacked it around a few times, and the CEL never came back on so I thought I fixed it..... until it came back on today! So I blame this thread, lol
Charlie (Fierofool) the good guy that he is, has volunteered to be the test case on the VS6 replacement. I believe it will work out fine but we need to locate a connector source as the VS6 uses one different from the Fiero unit.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Charlie (Fierofool) the good guy that he is, has volunteered to be the test case on the VS6 replacement. I believe it will work out fine but we need to locate a connector source as the VS6 uses one different from the Fiero unit.
I've used these guys in the past and their prices are good. Got a message into them to see what they come back with. The Repair Connector Store
I'll try to get the swap done by next week. Right now, I've just gotten the car able to drive after an engine swap and the alternator fails. Weather around here isn't cooperating on outdoor work, either.
It's installed. Just waiting on my harness connector to arrive on Tuesday.
Stock installation of EGR Solenoid:
Replacement VS6 EGR Solenoid from a 1988 S10 2.8 V6.
Nice!
You had mentioned de pinning the fiero connector and plugging the pins into the s10 connector. Im pretty sure the pins in the plug are different... Like one set is male and the other is female different.
The pins on both solenoids are Male. Both harnesses are female. Rather than cut and splice in the smaller harness plug I'll just transfer the stock wires. It could be easily converted back if ever needed. I don't like splicing unless there's no other way.
Edited: The replacement harness is female so it must be spliced into the factory wiring.
[This message has been edited by fierofool (edited 07-17-2021).]
Know the feeling. Just looked it up in an old 1993 Silverado manual. The install there follows the exact same wiring marking sequence A.B.C.D. on the VS6 EGR solenoid as on the Fiero unit except for C the fault switch which is left open. It may not set a code or it may require hooking to pin A ( 12V) to eliminate the code from setting. I would leave it open to start. I believe Fierofool is going to try it. The bottom line is that if we wish to keep stock 2.8L EGR operation, there may not be any other replacement alternative available.
I suspect it would NOT be a good idea to connect pin A and Pin C together, FWIW.
If you wish to keep from setting a code 32 for a problematic solenoid, you can supply constant ported vacuum to the solenoid's vacuum switch by (IIRC) connecting the grey plastic tube from the throttle body to the switch's side port (with the 90* rubble connector).
skywurz, you are correct. When you questioned it, I went back to look and indeed, the factory plug is male and the VS6 solenoid is male. So, the new VS6 harness would have to be spliced in. Thanks for questioning.
I suspect it would NOT be a good idea to connect pin A and Pin C together, FWIW.
If you wish to keep from setting a code 32 for a problematic solenoid, you can supply constant ported vacuum to the solenoid's vacuum switch by (IIRC) connecting the grey plastic tube from the throttle body to the switch's side port (with the 90* rubble connector).
Would that keep the EGR valve open all the time or is that just to trick the ECM?
hi Charlie, Feeding ported vacuum to the ECM gives it close to the readings it 'expects' and keeps it happy (no code 32). The solenoid continues in it's iffy condition of course. Still, replacing the bad solenoid with a good one is certainly the better option. Thanks for all you do.
Doing well, thank you Charlie. Hope you and your family are doing great! Missing my Mera but he went to a good home in Wisconsin. https://www.fiero.nl/forum/...77195-174.html#p6928 With all the thick wildfire smoke here now, summer driving was not much fun so it was best to let him go play in the sunshine. Still, with the rear toe adjusted down to the millimeter, Rex drove Amazing! He was soo sensitive to the rear alignment, tho solid mounting the engine cradle helped a ton too. Fiero's sure get under your skin. Miss you Rexie!
UPDATE: Studying the component I believe the way to not get the check engine light fault code to come on. If it happens you connect the wires that go to pin C and D together. In other words you ground the wire originally going to pin C. That should do it but you might need t add a bit of resistance there. I'll get out an old used unit and measure it. Meanwhile I suggest trying the unit as is and see what results.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 07-18-2021).]
I suspect it would NOT be a good idea to connect pin A and Pin C together, FWIW.
If you wish to keep from setting a code 32 for a problematic solenoid, you can supply constant ported vacuum to the solenoid's vacuum switch by (IIRC) connecting the grey plastic tube from the throttle body to the switch's side port (with the 90* rubble connector).
I corrected this. Should have said connect wire at pin C to pin D ground. Doing it by correcting A and C is wrong. My error. Sorry.
My question is, is the egr solenoid from the s10 variable? if so does it open the same amount as the stock one given the same voltage or resistance or whatever it uses? Im pretty sure the stock solenoid can open like only 50%, which changes the timing correspondingly. If the solenoid is only off and on that could be a problem. Also tricking the computer that theres always vacuum could also be a problem, because id think it would think that the egr is fully open and advance the timing. I might be wrong on this tho
This is only a guess. The solenoid is either on or off. No 25%, 50% or any increment. Open or closed. That allows vacuum from the manifold to be applied to the EGR valve. The EGR valve might open partially, depending upon the amount of vacuum applied. Again, just a guess.
This is only a guess. The solenoid is either on or off. No 25%, 50% or any increment. Open or closed. That allows vacuum from the manifold to be applied to the EGR valve. The EGR valve might open partially, depending upon the amount of vacuum applied. Again, just a guess.
The EGR solenoid operates on a pulse width modulated signal from the ECM. The faster the pulses, the more EGR action results. It is a variable parameter. It is either open or closed but at a cyclic rate. Think of a blinking light. the slower the cycle the less the light and the faster the cycle the more the light.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Could the internals from the S10 EGR solenoid be used to rebuild the Fiero solenoid? That would be ideal. Not sure which part normally wears out but I assume it's the copper windings inside. Perhaps that is also the same size as the S10 solenoid.
By comparing appearancs and dimensions, I would say no. The S10 unit is a flat box. The round portion of it contains a foam air filter. Any solenoid inside the main case would be much smaller than the Fiero solenoid.
While corrosion on copper windings is common defect, a sticking spring/block-off plate is also common, and of course a break in the tiny vacuum line to sensor is popular.
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