I was taking a look under the hood today at some old work that was done on my 94 z28 and noticed that it looks like something is missing. Can anyone tell me what should be connected the to connect that has nothing? It's also not bolted down to anything like in the photo of the new engien. It's just laying there on the engine, as you can see. I don't even see another hose in there to connect to the sensor. My impression is "What a chop job". The car starts, and runs okay, but the SES light is on and I cant find anyone who can do an OBD-1 scan on a 94 camaro. I could read manuals, understand some of it, but I am no mechanic. Second photo is of a new engine from that year. LT1 5.8 Liter v8. Looks to me like some part of the fuel sensor system. Any info appreciated. Tempted to take it to a Chevy Garage, but expecting that to cost more than the car is worth.

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Looks like its for your evap system. Might want to put a vacuum cap over the open port incase it still cycles..... could be sucking some dust in when it opens

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

 

Thanks Shoebox - I was looking at the diagram on the cover under the hood, just today as a matter of fact, and it is definitely an evap bypass (the hose is missing and not returning to the evap can) done by one of my mech's over the years. Looks like they unplugged the return to the evap can and unplugged the hose to the EGR solenoid from the EGR valve too. Dumping the emission into the engine bay. Hmmm. Is that a bypass of the EGR system? Certainly looks like an attempt. SES SES LOL Gonna try to track down someone who knows more about it than I do for a reasonable repair. Most likely causing the SES, and some other issues. Read that the gas tank could crush out, actually, when I opened the gas cap after it was setting for a very long time, I heard a vacuum sucking noise come from it, like that noise when you open a pickle jar, only a lot louder and longer and more of it. lol Will cover the opened port until I can get a tech to look at the evap system. Thanks.

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Actually, looks like they unplugged/removed the feed from the charcoal canister to the solenoid (the one that remains is connected to the TB). Air (ccv) and vaporized fuel would go into the TB when the solenoid is opened, if the feed were actually there. But since it isn't there, right, I better cap it or maybe get dirt into the TB. AH HA! So the evap system is not functioning, since no feed line is attached. And the sensor is coding up hence the SES light (perhaps). I have a 12 pin OBD1, I jumped the A&B ports on it, turned key to on position. The SES light did not come on but the engine fan started running. Without the SES flashes, that jump wont work for code reading. Any thoughts on that? Thanks Again.

 

I traced it better today and the bottom hose on the sol goes to the can. The current no hose outlet should go to the TB - they have a rubber cover over the TB connect. Saw online that the 90 degree elbow for that is not available from GM, and people have been using rubber spark plug covers in its place to make the connect, but only certain ones plug covers fit. I'm gonna cover the outlet that has no hose on the sol as you suggested, just in case it actually comes on some day, and leave it like that for now. Ignore the SES, and chug on down the road. Check the gas cap often to release any vacuum issue I had at the tank at one time. It's an LT1 and never really known for it's great gas mileage and low pollution levels anyway. I think my pressure washer is fumier than the car at this point. lol

 

You can find vacuum tubing connectors (Example Dorman #47411 if you search it)

Or if you rubber hose that fits tight you can get plastic elbows that will fit on inside and make your own since the above is for plastic tubing.

Not saying it is critical, but it might be worth considering a new solenoid as well if you decide to do anything with it. It could be gunked up after stuff getting into it for a while.

If you look up the old Mac Mentor scanners, there are a bunch for sale on Ebay. I kept mine when I upgraded specifically for my 94, It would let you see actual codes coming up and if you bring it in anywhere the salesmen mechanics wouldn't be able to upsell you too much. If they had to get a scanner that would work for a 94 they would probably hide it in the bill anyways..... and you wouldn't get to keep it.

It's obsolete but it will read up to 2018 (last I used mine) and can scan other modules as well... Also shows live data for sensors and switches

 

Thanks Stoggy! When they removed the hose they couldn't replace, they kept it. LOL - It probably went into someone else's car. That was long ago. 2013 I think. Anyway, if I go there, will get a new solenoid for it as well. So it will be ground up for the tube replacement. Posting a link here that I think wont work unless you copy and paste it. www.youtube.com/watch?app=desktop&v=8vbroc6KMmo But this guy uses a spark plug wire boot from a Riviera and its a perfect fit. Also, thanks for the tip on the scanner. I need one. I took it to a shop that promised they had a scanner to use and when it didn't fit, they told me my car was an OBD 1.5 which is total bunk. The 1.5 was only about a few software updates in a few Corvettes, and had nothing to do with the aldl pin type 12/16, or so I have read here. I need repair shops, but I like not being blind sided when I walk in. So yes, codes will help me on that one. Photo of the old spark plug wire boot the guy used - perfect fit. Oh, By the way, do you happen to know the model number of the MacTools scanner that works on your 94 Camaro?

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I think the wonky thing about our 94 is it is OBD1 protocol with an OBD2 connector, I am not 100% sure which model I have and I'm only halfway through my work set so I wont be home until the end of the month.

Physically it is identical to this one, (2.0, 3.0 and 4.0 are just the software update levels if you see that while looking, you can't tell without pulling the chip out or on the start up screen it will tell you)

This one looks inexpensive, complete and if it isn't updated will still work on your car. Just some capabilities might not be added yet....
https://www.ebay.ca/itm/126166267508

This one looks complete and updated (mine is only to 3.0) but is a bit more money. If the other one isn't updated it might cost a comparable amount to get it to this level. ( Sorry I don't know how to do anything other than copy and paste link)

https://www.ebay.ca/itm/16651199880...7064556144&itmmeta=01HPMW4CDMNRPR8RAYY38APCXK

If any chips are missing you can always get this cable and it will hook up to everything it is capable of hooking up to
https://www.ebay.ca/itm/19621996597...2017012324&itmmeta=01HPMX4QX8VXN05A7QADWA5SBZ

 

Thank you Sir. I will check them out. Happy Day!

 

stoggy94z - Several wonky things about it. The 94 z28 has an OBD1 ALDL (12pin) but codes will not flash on the 94 to the dash / SES light etc. Need a scanner for that. So took a leap of faith and picked up and brand spanking new Actron CP9690 That claims to have OBD1 and DTC for GM 1984-1995. After purchasing it on ebay, the price for it came down on amazon by about $10. But anyway, it arrived today and am going to check it out this weekend. The one on AMZ linked here. described here -
Actron CP9690 Elite AutoScanner Kit Enhanced OBD I and OBD II Scan Tool for all 1996 and newer and select 1984-95 vehicles

Ordered a new PCV valve for it too, just because the old one is old and the new one was 8 bucks. Thanks for the info and the links about scan tools. Will report my results when I play with it more.

 

I have recommended the 9690 for people with OBD1. Should work.

 

Worst case it will work on my 2013 Mustang. I appreciate you Rob! You are one of a kind.

 

I am so totally jazzed up right now. The cp9690 said 33 and 34. An hour later I have a new MAP sensor installed. It fired right up, and no SES light. Happy Day! I <3 my CP9690

 

I am so glad that I can access the info in this blog!!! Update - So then I thought I was getting an overheat situation on my test drive. Why, because the temp gauge was getting close to the red marks. Today I did a coolant burp and replaced the radiator cap, plugged in my scanner and voila - My Actron cp9690 got up to coolant temp 227 which is exactly the spot where I heard one of the fans kick on. I checked all the relays for the fans, the volts at the relay sockets, and that all read good. I jumped A&B at the OBD1 port and the fans started running. So the fans and the circuits are operational. My Actron pans out to pretty much exactly what this blog reports should happen with coolant temp etc. I guess my mostly city driving will run the car a bit hotter since it's stop and go, mostly stop (lol) and the engine doesn't get much airflow in stop mode. lol So maybe there really is no problem with it after all. I do plan on doing at least a drain and fill, if not a flush and fill, and it's time to replace the thermostat when the rad is empty (opti avoidance). Some fresher coolant will help with lower temps I presume.

From another similar blog:

Early production 1994 - the first fan should turn on at 226°F, second fan at 235°F. (Under hood box will have 2 fan relays)

Late production 1994 - both fans on low speed are 226°F, both fans on high speed at 235°F. (Under hood box will have 3 fan relays)

The center hash mark on the coolant temp gauge is 210°F. It is marked on the Firebird, but not on the Camaro gauge.

http://shbox.com/1/temp_gauges1.jpg

The next hash mark to the right is 235°F, past that on your 1994 the gauge shows red. In 1995 the Camaro gauge was modified so that 1/2 of that space was no longer red. That would put the red starting at about 247°F. There are no significant differences between the 94 and 95 engines and cooling systems.

GM designed the engine to run at 210°F. That yielded the best combination of emissions and fuel mileage.

What I still need to know is what is the temperature on the dash gauge when you feel the engine is “running warm”? Some people seem to feel that anything past the midpoint of the gauge is too hot. That’s not really the case. We can infer from the lower fan turn on temp that GM does not see any problem as long as the temp is below 226°F.

Thanks for all you guys do!

Dylan

 

I love the live data stuff on the scanner. Now I need to research what all of it means.

Edumacation is a good thing,

 

It's running hotter now because I fixed it and the "Emergency" SES fans don't kick on when I start it up. Now they only come on when it gets really hot. Oh Brother. Will probably get a much better gas burn now.