Unknown item in engine bay

[Railglobe]

Would anyone be able to identify the item that leads from the hose I'm pointing to in the engine bay? Neither this hose, nor the one my key is resting on, is attached to anything but this item (my guess it's from Darth Vader's respirator). I'm trying to track down a vacuum leak due to poor emissions at the MOT and theses hoses were identified as not attached. Should they be to something?
The second picture seems to be a fan of some sort-which runs regardless of the engine ignition being on or not-so it has been disconnected to prevent battery drain. Any advice as to how to proceed to fix would be greatly appreciated.
Thank you

 

[Mick Howes]

Not sure about the first question, but the second is easy, that is the blower for the heater fan, and your problem is a knackered Blower Control Module, the module is on the right side of the engine bay on that flat panel near to the windscreen. The module controls the fan and aircon. To stop it for now, just unplug it, cheap unit to replace and easily available from Corvette Central in US.

 

[Chevrolet]

'88-'91 C4 Corvette TPI MAF Speed Density Secondary Air Injection By-Pass Valve:

88-91 C4 CORVETTE TPI SPEED DENSITY SECONDARY AIR INJECTION BYPASS VLVE 17088106 | eBay

Find many great new & used options and get the best deals for 88-91 C4 CORVETTE TPI SPEED DENSITY SECONDARY AIR INJECTION BYPASS VLVE 17088106 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Presume you don't have a Haynes manual for the car? Worth having.

 

[Mick Howes]

Just to clarify the module loaction, the attached pic should help

 

[Chevrolet]

Any advice as to how to proceed to fix would be greatly appreciated.

Have you just bought the car/What year is it? Don't know why the Bypass valve is disconnected, or where the hoses attach to (didn't have them on my '85). You should be able to find that on the internet, if a club member can't help. Maybe it had stopped working or, as a guess, a previous owner disconnected it as part of smog/emissions equipment removal/disconnect job, to increase horsepower (look on web). e.g. the smog air pump above the front of the engine/driver side has been removed and replaced with just a pulley (if your year car had one when new). You can see what error codes are on the car (if any) by using a bent paper clip in the diagnostic port below the dash under the steering wheel. Hope that helps?

Update: Just seen this, so you know about paperclips/error codes, although obviously no reply from you on that one:

Stalling and Service Engine light comes on

 

[Railglobe]

Not sure about the first question, but the second is easy, that is the blower for the heater fan, and your problem is a knackered Blower Control Module, the module is on the right side of the engine bay on that flat panel near to the windscreen. The module controls the fan and aircon. To stop it for now, just unplug it, cheap unit to replace and easily available from Corvette Central in US.

Thank you for the info. I'll look into it.

 

[Railglobe]

88-91 C4 CORVETTE TPI SPEED DENSITY SECONDARY AIR INJECTION BYPASS VLVE 17088106 | eBay

Find many great new & used options and get the best deals for 88-91 C4 CORVETTE TPI SPEED DENSITY SECONDARY AIR INJECTION BYPASS VLVE 17088106 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Presume you don't have a Haynes manual for the car? Worth having.

Alas, no. I don't have one....yet. It is quite a name for a valve.

 

[Railglobe]

Just to clarify the module loaction, the attached pic should help

Thanks again

 

[Railglobe]

Have you just bought the car/What year is it? Don't know why the Bypass valve is disconnected, or where the hoses attach to (didn't have them on my '85). You should be able to find that on the internet, if a club member can't help. Maybe it had stopped working or, as a guess, a previous owner disconnected it as part of smog/emissions equipment removal/disconnect job, to increase horsepower (look on web). e.g. the smog air pump above the front of the engine/driver side has been removed and replaced with just a pulley (if your year car had one when new). You can see what error codes are on the car (if any) by using a bent paper clip in the diagnostic port below the dash under the steering wheel. Hope that helps?

Update: Just seen this, so you know about paperclips/error codes, although obviously no reply from you on that one:

Stalling and Service Engine light comes on

Thank you for your info. I haven't done the paper clip test yet-sort of gave up-got despondent with the car and stored it away until recently. It is at a mechanics at the moment who has identified loose spark plugs (another mechanic appears to have just given up finishing a job), a fair bit of soot and that is just the start. Had the car quite a few years now. It is an 1989 Vette which is fab

 

[Redlevel]

For what its worth, years ago I deleted my A.I.R. pump including its electronics and wiring under the plenum. Any vacuum ports were just sealed and the EGR disconnected.
At the same time, I removed all the AC system, and replaced the pump with an idler.
I have no vacuum lines (all ports sealed) apart from the fuel pressure reg and the heater/demist and also the brake servo.
My vac. sphere is gone as is the charcoal can complete with all vacuum lines, solenoids etc.
Never had a problem and never had a code come up either.

 

[Kicks on 66]

Thank you for the info. I'll look into it.

Not sure about the first question, but the second is easy, that is the blower for the heater fan, and your problem is a knackered Blower Control Module, the module is on the right side of the engine bay on that flat panel near to the windscreen. The module controls the fan and aircon. To stop it for now, just unplug it, cheap unit to replace and easily available from Corvette Central in US.

Micks correct about the blower module. I have a one somewhere that may be use if its the correct one for your year. There are two or three types I think.

 

[Chevrolet]

Micks correct about the blower module. I have a one somewhere that may be use if its the correct one for your year. There are two or three types I think

Generous/Nice! The photo of the blower above looks like the Harrison (made in Australia) one I had in my '85. As you can see in photo above its labelled "R12 Charge." Had my airco changed/updated to R134A by Ian Goss. Ecklers do an update kit for '85-'87s:

Conversion Kit,R-134a,85-87

Your factory C4 1985-1987 Corvette came with an R12 based A/C system. It provided ice cold air...even on the hottest days. Over time, the seals in your compressor can dry out, bearings can seize, and you can get leaks in your system. Fixing your R12 based AC would be great "if" you could get...

www.ecklerscorvette.com

Blower module for 86-89:

Module,Blower w/AT Temp,86-89

This stock replacement blower fan module is manufactured by GM or by one of its authorized suppliers as a factory replacement part. You will find the fit and performance meets all GM specifications. Using stock replacement parts from Eckler's, such as this blower fan module, is a sound...

www.ecklerscorvette.com

See that on a later C4s you can, according to this, save money by buying the module for a Jeep Cherokee, which is the same item:

 

[Railglobe]

Thank you all. One thing I forgot to mention is the code flashing is 24, but the Service Engine soon light comes on after driving the car for a few minutes (not idling for 10-15 mins), and the car wants to stall and gets very lumpy.
Any advice greatly appreciated

 

[JonnyC4]

Code 24 is "vehicle speed sensor. I had it once with a C4 over here and we changed the sensor first, but it came back and we needed to get the ECM replaced.

After that the owner replaced the ECM, it stayed away.

 

[Lankybloke]

Would anyone be able to identify the item that leads from the hose I'm pointing to in the engine bay? Neither this hose, nor the one my key is resting on, is attached to anything but this item (my guess it's from Darth Vader's respirator). I'm trying to track down a vacuum leak due to poor emissions at the MOT and theses hoses were identified as not attached. Should they be to something?
The second picture seems to be a fan of some sort-which runs regardless of the engine ignition being on or not-so it has been disconnected to prevent battery drain. Any advice as to how to proceed to fix would be greatly appreciated.
Thank youView attachment 5830View attachment 5831

Is the first picture an A.I.R Air Injection Reactor? I have a'90 Chevy Pickup and it has something similar as part of the emisions set-up. Just a thought...