SMC pump going bad?

street6

pushing stock limits
Joined
Feb 13, 2009
Got a question concerning my SMC alky kit. Recently I have noticed that sometimes the alky is not coming on (starting to spray) at where I have it set at. The pump is turning on however sometimes it seems like it takes a while to begin spraying.

Tonight I used the test button the check the alky kit (parked w/ ignition on) and after it began spraying the alky gauge quickly showed 100psi. But as soon as you let go of the test button, alomst instantly all pressure is lost in the alky lines. Should'nt it hold some pressure? I'm thinking I have a bad
in-line check valve which is allowing line pressure to be lost instantly after the pump stops. Or, is there such a valve in the pump itself?

Anyone got any ideas or familiar w/ this SMC kit?
 
If the kit is activating at the desired boost level, then the electronics should be working. In other words if your sending power to the pump.. and its not pumping.. then you have a bad pump. You can confirm power to pump simply using a DC multimeter and connecting it across the pump wires. Kit lets say activates at 10 PSI.. you see 6 volts on the meter.. electrically its working.

Even if it has a check valve, the pressure it can retain would be negligible. As most check valves are 2-10 PSI pressure. So it losing pressure would be normal.. taking a long time to prime would be abnormal.

Sorry I cant off any more help. And you have to understand some SMC kits are now 10+ years old. So not knowing what generation kit you have.. round bottle, square bottle, factory bottle.. internal pump/external pump, etc.. many variations and each one had its own thing.

You may try contacting Steve at SMC. His number is posted on a recent thread. I dont know if he's still taking calls on the product.
 
Thanks for the reply...we spoke via telephone a few days ago as I was inquiring of buying your kit to replce the SMC kit I have.

The SMC kit is the newest version (external pump), and it has only seen minimal use. I verified the electronics are working correctly, as the pump turns on at the desired boost setting. It is just taking long to actually start spraying.

Was just not sure if the pump itself had some sort of check valve built in. It looks as though there is a check valve built into the kit which is positioned close to the nozzle, but should'nt there be a check valve closer to the pump so after the pump stops the methanol does not run backwards emptying the lines?

Guess I'll try replacing a check valve or add one to see if it fixes the problem. If not I'll be calling you back to order your kit, thanks.
 
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