EGR Solenoid 91 / injectors

[Fastcossi]

Hi everybody here

I am coming from Austria and I am new in this forum, running a 91 C4.

For the reason i have registrated today i like to say first hello again to everybody in here .
Using the search function i´ve already tried to find answer to my both questions i have and have also found some posts, but couldn´t find realy the answer.

Today i have seen that may EGR solenoid is not working correct anymore (isn´t thight anymore) so i have to change it but for the 91 the solenoid is discontinued.
Some post indicating that some people have tried to use the solenoid of the 92 model but i couldn´t find any answer if this is realy the way to go and if it was getting working.

Can anybody tell me if it is possible to use the 92 solenoid or if there is an other solution :confused

Second i like to change my injectors. My little vette ist original, no mods to the engine so i like to use standard 22 lbs injectors.

Whas the best solution: use the original again or swap to some Bosch injectors?
If a swap is better, which injectors can / should i use?

Thanks for help in advance

Regards

Fritz

 

[Fastcossi]

Nobody can helpe me :ugh

;help

 

[gw962]

I will be swapping out the defective solenoid on my '90 on Wednesday with a solenoid from a '92. I'll let you know how it works.
I've read some posts earlier that mentioned the swap, but I haven't found any additional info.

 

[Fastcossi]

Perfect
I had the same problem. There are some posts about the plan for a swap but no information it it realy worked :eyerole

I think if you can tell us if it´s working or not this will help a lot of guys in future

 

[JAKE]

I'd go with the stock injectors. Going with different size injectors calls for re-programming.

I bought a new EGR solenoid from GMPARTSDIRECT for my 96.

Jake

 

[Fastcossi]

Hi Jake,

The Bosch injectors i bought yesterday are stock specification. They have 22 lbs like the original ones but the construction is about 10 years younger than the original ones.

The solenoid of a 92+ is available everywhere. The problem is to become a 91 and down. The design of the solenoid change from 91 to 92.

 

[Fastcossi]

@gw962

Any news about your swap?? :confused

 

[gw962]

Sorry for the delay...
After a little modification of the mounting bracket and running some new vacuum hose, I finished the swap late Thursday.
Cleared the codes and took it for a test ride at highway speed. Naturally,:confused, it set code 32 again.
I had time to do a quick test of the solenoid and EGR valve holding vacuum and they both passed. The next step is to follow the electrical testing tree in the FSM.
I do know that neither the solenoid or valve would hold vacuum as set out in the FSM, which is why they were replaced.
It's not a difficult swap but to make it easier, remove the throttle body for more room. ANd while you're at it, this would be a good time to disassemble the TB and clean it.

 

[Fastcossi]

That means the EGR solenoid itself can be used (if all is thight) and the electrical connection is the same am i right?

I have already all disasembled cause i am also changing the injectors

 

[gw962]

The solenoid will work correctly. You will have to bend the mounting bracket to fit on the coolant neck and next to the fuel rail. Since you have it apart for injectors, it should be easier.

You will need a different weatherpak connector and I found one here:
http://www.tpiparts.net/inc/sdetail/4298

It states 93 - 97 but it does fit a 92 solenoid.
Good luck

 

[Fastcossi]

Many thank´s again!
I have now checked both service manuals ( the 91 and the 93 ).

Here it is indicated that the 91 solenoid is a normally open solenoid and the 92+ has a normally closed solenoid.
How have you solved THAT? Or does this have no influence?

 

[Fastcossi]

Solenoid

I got my 1992 solenoid now too and i checked the function of both (the 91 and the 92)
They are working different cause the 91 is a normally open valve which has a open vacuum line to the EGR during the key is not turned.
The 92 is normally closed and has a closed line to the EGR (and the second line is open to atmosphere) during key is not turned.
I realy don´t understand how you got it working on a 1991 :confused

 

[gw962]

I didn't know there was a difference. :confused
When I tested the solenoid per the '90 FSM ( ground A-B on ALDL, put 10hg vacuum on the solenoid and see if it holds. Unground A-B and vacuum should drop) it tested OK.
Of course, I'm still throwing a code 32, but I was thinking carbon in the passages, since all other tests were OK.
I'm thoroughly confused now. Anyone else have ideas?

 

[Paul Higg]

Jake, now I'M bookmarking this page! I ALWAYS learn something new, thanks!

Paul

 

[Fastcossi]

I would like to keep you updated about the solution for the 91 C4 EGR solenoid.

I ordered a 1992 solenoid too, to check the functionality.
As i could found out the 1992 solenoid is working in a different way than the 1991.
The 1991 solenoid is a normal open solenoid (NO).
The 1992 solenoid is a normal closed solenoid (NC).
Usage of a 1992 solenoid on a 1991 is not possible without modifications on the vaccum line connections of the solenoid.
On the 1992 solenoid the breather on the backside should be the line which is going to the EGR, and the right front connection is used for the vaccum line from the plenum - than it would work.
But i have found an other solution which can be used.
Take the solenoid for a El Camino 85-87 (Standard VS13). You can still get it for example at Rockauto (where i have ordered) or Woodys Auto Supply.
This solenoid is EXACTLY the same (even the vaccum line connection is exactly the same) like on the 1991 - only the mounting bracket is different - but this is easy to modify

 

[Paul Higg]

If you have the FSM it will tell you to look at the numbers on the EGR and the code tells you whether it is NO or NC. You can get one at Vette2Vette.com. Jason has EVERYTHING (just about) and he is reliable and his prices are great.

Paul