need help with methanol problem!
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
need help with methanol problem!
i went to the track today and my car quit! i noticed that meth was coming out of mt TB and the pump would not shut off! i found a vacuum switch and when i handled it the pump went off i think the switch is the problem! i never had any problems before my tuner reset my rev limit and shift points it must be pulling more vacuum I'm not sure can you help me with this problem or have you ever had this problem thanks Scott
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
i went to the track today and my car quit! i noticed that meth was coming out of mt TB and the pump would not shut off! i found a vacuum switch and when i handled it the pump went off i think the switch is the problem! i never had any problems before my tuner reset my rev limit and shift points it must be pulling more vacuum I'm not sure can you help me with this problem or have you ever had this problem thanks Scott
The HOBBS switch works on BOOST pressure as opposed to vacuum. You can test the switch with a pressure tester, MIGHTY VAC, use a test light and see where it comes on at.
There is a small black plug in the bottom and you can turn it to have it come on sooner or later during B@@ST!
Thanks,Matt
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
It has to be a Hobbs switch. It's a pressure sensitive switch that closes when it reaches a certain pressure. Who made your kit? The Alky Control kit uses a MAP sensor and increases pump voltage with increasing boost, so you get more meth with more boost. A Hobbs switch is on/off. I use one for my secondary fuel system and Boost-A-Bump
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Sounds like the HOBBS switch has malfunctioned!
The HOBBS switch works on BOOST pressure as opposed to vacuum. You can test the switch with a pressure tester, MIGHTY VAC, use a test light and see where it comes on at.
There is a small black plug in the bottom and you can turn it to have it come on sooner or later during B@@ST!
Thanks,Matt
The HOBBS switch works on BOOST pressure as opposed to vacuum. You can test the switch with a pressure tester, MIGHTY VAC, use a test light and see where it comes on at.
There is a small black plug in the bottom and you can turn it to have it come on sooner or later during B@@ST!
Thanks,Matt
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
To find a replacement, type Hobbs switch in Google. Get a normally open, adjustable, sealed one like Matt's talking about. The best place I can think to get one is from a turbo supplier.
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Here is where you can learn a little about these HOBBS switches:
http://content.honeywell.com/sensing.../catswitch.asp
Thanks,Matt
http://content.honeywell.com/sensing.../catswitch.asp
Thanks,Matt
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Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
my switch doesn't look like the Hobbs on that link that one on the link is like a oil sending unit mine is plastic! square! help maybe I'm messing with the boost a pump switch 
My tuner installed it all i know its the new kind braided lines it can run 100% meth 
Burning Brakes
Joined: Jun 2006
Posts: 835
Likes: 0
From: fayetteville NC
i had a problem before with meth pump not turning off and it was my battery. once i went below certain voltage the pump started pumping it was weird. it took me 1 week to find out my battery was the problem. so go get your battery check belive me it was that stupid.
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
will do but my motor lost #1 cylinder today at the track i think my meth pump quit! I'm sick thanks for your reply,Scott
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Man, that really sucks! 
As for the Meth, before you run that car again, PM me and I'll give you my phone #. I can share some tuning and installation methods on the meth to prevent engine failure. If it quits for any reason, it will pull as much timing as you choose and do it quickly as well as add fuel to compensate for the loss of the meth. 
As for the Meth, before you run that car again, PM me and I'll give you my phone #. I can share some tuning and installation methods on the meth to prevent engine failure. If it quits for any reason, it will pull as much timing as you choose and do it quickly as well as add fuel to compensate for the loss of the meth.
Former Vendor
Joined: Oct 2007
Posts: 2,032
Likes: 6
From: longview tx
Scott i called you back a few mins ago. Your kit is the AIS meth kit and that switch IS a pressure switch. it has a little ALLEN screw in it to adjust the METH. also, why would you think you popped the #1 CYL? most all the time is is the # 7 or 8 CYL on the stock motors with stock intakes. Did you check to make sure that the two wires that went to the switch were not touching each other and making contact and thats what was making you pump run? and if the pump went out you coudl have got DET. did you hear anything at the track that sounded like marbles rolling around?