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WhoolaWalker · 01-25-2017, 03:18 PM

Soooo to all of the people that have been doing this forever... I once again call upon your wisdom. I failed the EVAP as well as the ignition timing... Any one have any suggestions on what I'm going to need to buy for the repairs on my 1984 Fleetwood Pace arrow with the Chevy 454. Thank u so much and as always I am greatful for any and all help.

BFlinn181 · 01-25-2017, 08:30 PM

Looks like a new gas cap is called for. The timing and the fuel evaporation failures could both be a result of bad vacuum. I'd replace the gas cap then test the vacuum system with a gauge. While the engine is running, WD-40 can be sprayed on vacuum lines. If the idle suddenly rises, you've hit a vacuum line leak. Again, with engine running, use vice grips to pinch off vacuum lines to HVAC control to eliminate all those connections as being the source of a leak.

garys 68 · 01-26-2017, 08:30 AM

IIRC the evap on carbed chevys is a pretty simple system.
First off, get the correct gas cap. Having a vented or missing one affects the evap system.
I suspect the evap failure is either due to the gas cap or missing components since I cant think of a functional test. Since RV emisions can differ from trucks (due to GVW) and CA can differ from other states, you'll need to look for a sticker showing the components and hose routing to determine what needs to be there. Generally it's just a evap canister with inlet hoses going to carb and tank. Outlet is generally plumbed to PCV line.
Timing could be as simple as setting to original specs.
I'm really glad I don't live in CA.

WhoolaWalker · 01-26-2017, 10:32 PM

Man... San Diego has an oversized vehicle band... If your found on any street from 2-6 am u get a 130.00 ticket!?!?!?

soundwve · 02-07-2017, 08:13 PM

Quote:

Originally Posted by garys 68

IIRC the evap on carbed chevys is a pretty simple system.
First off, get the correct gas cap. Having a vented or missing one affects the evap system.
I suspect the evap failure is either due to the gas cap or missing components since I cant think of a functional test. Since RV emisions can differ from trucks (due to GVW) and CA can differ from other states, you'll need to look for a sticker showing the components and hose routing to determine what needs to be there. Generally it's just a evap canister with inlet hoses going to carb and tank. Outlet is generally plumbed to PCV line.
Timing could be as simple as setting to original specs.
I'm really glad I don't live in CA.

My '84 Jeep Cherokee had a thermatic vacuum switch in the EVAP canister purge line to the carb. It was mounted on the intake, in the water jacket, with 7 vacuum ports on it. 1.25" wrench required to remove. Mine was dead, and no vacuum flow even with engine at operating temp for 20 minutes. (I failed emissions too.)

I've seen Jeep, Dodge and Ford V-8s with these switches. Chevy may have it too. Be aware of it, just in case. But I also agree with the other replies. Replace gas cap first. It's cheap, it failed anyway, and isn't as much of a pain to replace.