Does anyone know where I can buy a EGR solenoid for a 1991 GTA 305cui TPI Motor Code-F ?

I didn't fin them by Rockauto or on ebay. Is it right that I can also use a Solenoid from a 1995 Caddy Seville? And if- will it be plug an play?

 

Original TPI solenoids are not being reproduced currently. Word I've seen is the 95 Deville 4.9L one and LT1 solenoids work but you have to modify brackets, wiring and vacuum lines. There isn't any voodoo going on inside a simple solenoid so I'm going to test mine with the TBI solenoid I had lying around and see if it works. I'll post more info as I get my own results. Seems like there is conflicting info out there.
https://www.thirdgen.org/forums/tpi/...-solenoid.html
https://www.thirdgen.org/forums/tpi/...ks-camaro.html

 

Would be really interessting if the TPI cars runs with the TBI Solenoid's- what I read till now about the LT1 solenoids is that they don't work right with an TPI.

 

A egr solenoid is in basic terms a valve. Either it passes vacuum to the egr valve or it blocks manifold vacuum and vents the egr side of the solenoid(so the egr doesn't remain open). The only differences I can think of are...
brackets (which doesn't change the operation)
Vacuum line orientation (which also doesn't change operation as long as they're hooked up correctly. Only two possible choices)
Pigtail Connector (which doesn't change operation either. BTW the TPI ones I have are a weather pack connector while all the other is a Metric pack connector. In other words you'll need the correct connector to hook it to.)
Voltage required to energize the coil (which changes the power source, so if your system puts out 5v and the solenoid needs 12v then it won't work. And vise versa may burn out the coil. The speed density TPIs I've seen put out 12v. May be different on other models, MAF TPI, TBI etc.)
If the solenoid is normally open or normally closed (this is the big one. If the solenoid passes vacuum to the egr valve when it isn't powered by the ECM using it on a car that the ECM powers the solenoid at idle the egr will be open at the wrong time. So the solenoid being used needs to be open or closed depending solely on how the ECM operates it)
Lastly.. Duty cycle (how long the and often the ECM energizes the coil. May or may not burn out the coil by being charged too long)

My original solenoid is inoperative so I'm not sure if its normally closed or open. Both the LT1 solenoid and TBI solenoids I have work the same way. When they are not energized they DO NOT pass vacuum to the EGR valve. If the LT1 type and TBI type truely is wrong that leads me to believe that the SD TPI ECM requires it to pass vacuum UNenergized.

If that is the case then you and I both need to order a 95 Deville 4.9L solenoid to repair our cars. It may sound technical but its not.

 

ive used the tbi ones till recently. i found a 94 tbi truck uses a suitable solenoid. it has 3 ports tho. ones a vent for when it closes. had to change the pigtail. it was the same as our 90-92 washer pump pigtails. just an option.

 

I'm curious to see if the truck TBI solenoid operates differently than the Fbody TBI. I'm going to look into that. Cause if it is different it maybe a much cheaper alternative to the Cadillac one.

My results so far are inconclusive. I hooked up the working TBI solenoid correctly and everything seems normal. If I disconnect anything solenoid related, a vacuum line, the wiring etc, the idle remains normal and the same. Which is a little rough @650, but its normally rough with the cam. There is a small amount of vacuum coming from the throttle body as expected. I did note the ECM is telling the solenoid to activate, the solenoid clicks when I plug it in. That doesn't make sense to me but it maybe correct. The egr works and the passages are clean so I can personally rule those out. I was short on time so I only hooked it up, warmed it to operating temp and took it for a short drive. So I must have missed something. When I have more time I'll dig into it further and let you know.

 

From what i have read the LT1 solenoid will not work on tpi. It works the reverse operation of what a tpi solenoid does. Thats just what i have read

 

I just orderd the Cadillac Solenoid. I will let you know how it works when I installed it.

 

Let me know if it sends vacuum through it or if it vents when there's no power to it. The 94 Chevy p/u one works the same as the fbody TBI solenoid. If its what I suspect then the Caddy one will work the same way.

 

http://www.ecklerscorvette.com/corve...1985-1990.html

That's what I used for my 91'.

 

I have removed all the EGR stuff from my car and I'd be willing to sell all of it to anyone who needs it. Message me if I can help.

 

Any word?

 

Just to update anyone with the same porblem. I tried the LT1 and Fbody TBI solenoids (both I had on hand) and the TBI truck solenoid. All three of those work the same. They're venting when the solenoid isn't energized. For grins I tried them on my car even though my harness is trying to energize the solenoid at idle(the opposite of what I'd want). They of course didn't work correctly. I picked up a AC Delco Caddilac solenoid for super cheap last week. It is sending vacuum through it when not energized. I hooked it up and all's well. My guess is the 85-90 corvette one Actarnoff listed works the same way.

 

napa lists it $120