Ok,

I have a 1986 Z28 Camaro, Carburetor, Manual transmission, 5.0L 305 V8.

Heres the deal:

Ive given the car a complete tune up, new spark plugs, wires, distributor cap, rotor, replaced oxygen sensor and thermostat. Went to junkyard and replaced the radiator overflow tank, but the cap still doesnt seem to lock air tight...

The fan wouldn't come on at 220 degrees like it was supposed to so I added a switch to the relay just so I could drive it without overheating.

The car had a gas leak at the fuel filter near the carb, just needed to tighten that bolt. so fixed that.

After that i replaced the ignition cylinder, so I had the battery disconnected for a couple of hours so it had time to reset as well, but it came back.

Finally got around to checking the code on the service engine light and it was cod 34:
"Differential Pressure Sensor - Leaking or restricted vacuum hoses; poor electrical connection, open or short in circuit; defective ECM."
I found out that was the same thing as the MAP sensor, so I found that, and it turns out the vaccume hose to the carb was missing altogether, so I put a hose in and the light went away.

After all of that it was still failing SMOG, so I took it to a smog mechanic and he found out the firing order was wrong, and one of my spark plug wires had burned on the exhaust, so he replaced thsoe and put the order right...MASSIVE DIFFERENCE, the engine was running fantastic at that point.

No he told me to hope that I hadnt ruind my catalytic converter from doing that...and I did.

When I took it to get it smogged after a 30 min drive, all of the numbers were High:

Comprehenzive Visual Inspection:PASS
Functional Check: FAIL
Emmisions test: FAIL

15MPH
HCPPM)
MAX:126
AVE:41
MEAS:158

CO(%)
MAX:0.79
AVE:0.13
MEAS:0.84

No (PPM)
MAX:1097
AVE:399
MEAS:1050



25MPH
HCPPM)
MAX:101
AVE:29
MEAS:101

CO(%)
MAX:0.59
AVE:0.11
MEAS:0.55

No (PPM)
MAX:927
AVE:332
MEAS:777


Only thing it failed was the "IGNITION TIMING"

and at the bottom it said
"This vehicle has failed the ignition timing check due to engine RPM being to high"

If by "engine RPM" they mean idle, then yes, it was about 1000 when the fan is on, but its between 600 and 700 when the fan is off.

So what does "Engine RPM being to high" mean? The smog guy said that he thought it was the catalytic converter because everything seemed high...And that backed up what the mechanic had told me could happen.

Does that sound like the problem? if so, any idea where to get a decent price, installed, or otherwise CA-legal catalytic converter?
Thanks in advance guys!

 

When you ran it on the device was the fan on? If so, it can alter your numbers on the smog.. Now wit fuel injected motors I know this to be true.. However on a carbed intake, not sure.. Yet this still may be the case

Adrian

 

The fan was on yes, And i know for a fact that was the reason for the high Idle..

but the car will overheat without the fan on....

Im not quite sure of a way around this problem...

Im thinking though, even if the fan is on, something must be getting those numbers high like that.

 

The fan being on the entire time will produce those high numbers. I suggest you go the route of a fan switch. Have it turn on @ 220, and cut off @ 200... Then the car will run @ it's normal configurment. And the computer won't compensate for the cold engine making it run rich

Adrian

 

With those numbers, do you think that had the fan switch been working it would pass?

Are there any tech articles, or schematics anywhere that show me where its supposed to be or how I can troubleshoot it.

Also, what is the Official name for it so I can look it up in my manual?

 

There is a trementous amount of information on this board for this situation my man... Just do a search up top and flip thru all the pages of brain food for the soul. You will find everything you need to know.

With those numbers, it look very similar to mine when I accidentally left my fan on and my smog tech kat, said it would not pass... I then remembered my fan was on... so i told him to turn the A/C switch off to deactivate the fan and presto!!! I passed wit flyin colors...

Adrian

 

Ok,

You were right, a ton of info...very helpful.

Ive located the switch and ordered a replacement 215 degree switch, and will replace asap, as it was only 12$

I do have a question that wasn't answered though... What specifically can I do to get the wire out of the switch?

From the top of the car, I can barely fit my hand in there, and I don't just want to pull it...Does it twist off? or something? I want to just check to see of I ground it if the fan comes on.

Thanks!