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Author Topic: Season start gremlins - fuel pump constantly running
Andy Robottom Verified Driver
Member

Region: NW
Car #: 113
Year : 1990
Posts: 145
Status: Offline
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Several off season upgrades in, head, ART tuned AFM, fat cat bumps stops and a little dyno time. As race day approaches, the gremlins have reared their ugly heads.

Mystery radiator leak - fixed, replacement on order.

After installing the repaired radiator, suddenly a check engine light, turned off the ignition, restarted no check engine light.

Ran to temp, no leaks, turned it off, cooled it down, turned on the ignition, and the fuel pump suddenly sounds like it could supply a small city with high water pressure, its working that hard - ignition on, not started. When started the idle is a tad variable.

WFT?

Forum search revealed only a single thread that related to "tuned AFMs" and "open flappers" causing a fault whose only symptom is a constantly running fuel pump. But why so loud?

MY thought is blocked fuel filter, which admittedly is older than is probably wise.

Do I change the filter?
Do I install a new fuel pump?
Do I just ignore it and see how she runs?

Thanks for any and all helpful suggestions.

Andy
(Increasingly wound up, because non of this has any track time yet. I'm not sure if its too much caffeine or too little sleep, or both)

--------------------
....drive your own line

Keith in WA Verified Driver Made Donation to Website
Pack Fodder

Region: NWR / Oregon
Car #: 88
Year : 95
Posts: 2000
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Andy,
This may sound dumb but you didn't leave a jumper in your diagnostic box between FP and GND did you? Been there on the track and it will cause both an intermittant check engine light at temp and the fuel pump to run constantly. Not enought sleep and too much caffine can easily cause that one.

I also had it run constantly with the ignition on but no jumper when my battery died and I had the car hooked up to the charger. Two easy problems but admittedly long shots.

--------------------
Keith Novak
(Will work for tires)

Andy Robottom Verified Driver
Member

Region: NW
Car #: 113
Year : 1990
Posts: 145
Status: Offline
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First place I looked, because that's just what it sounds like, and no, the jumper is off.

--------------------
....drive your own line

Keith in WA Verified Driver Made Donation to Website
Pack Fodder

Region: NWR / Oregon
Car #: 88
Year : 95
Posts: 2000
Status: Offline
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correction: I left the jumper in for timing causing the check engine light. (it's early) [Smile]

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Keith Novak
(Will work for tires)

davew Verified Driver Made Donation to Website
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Region: chicago
Car #: 72 and ?
Year : 90 and 90
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Your problem is in the air flow meter. When the wiper arm is adjusted for better performance it no longer swings back far enough to turn the fuel pump off. The cover needs to come off so you can bend the tab that opens the contact points for the fuel pump circuit.

Dave

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Andy Robottom Verified Driver
Member

Region: NW
Car #: 113
Year : 1990
Posts: 145
Status: Offline
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Dave

That sounds so remarkably easy. You don't by any chance have any images of the tab you identified. Afraid I would not have a clue, and would hate to upset the adjustments done dowm at ART.

That being said, I really appreciate your response.

Andy

--------------------
....drive your own line

B Wilson Verified Driver Series Champ
Gold Member

Region: Oregon
Car #: 68
Year : 91
Posts: 2359
Status: Offline
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Andy just open the top and you'll figure it out pretty quickly. When you turn the flapper mechanism back and foth with the key on, you will see and hear where the contacts are, and it should be fairly easy to figure out how to bend the tab so that when the flapper comes to rest, the concats are no longer touching.

-b

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Bruce Wilson
2010 Oregon Region Champ
2010 Monte Shelton Driver of the Year
2010 25 Hours of Thunderhill E3 and Under 2 liter Overall Champion
Oregon Region SM Class Advisor

Andy Robottom Verified Driver
Member

Region: NW
Car #: 113
Year : 1990
Posts: 145
Status: Offline
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Thanks!

With so many changes on the car, I'm might be wound a tad tight...

--------------------
....drive your own line

Muda Verified Driver Made Donation to Website
ComingToAMirrorNearYou

Region: WDC
Car #: #23
Year : 1991
Posts: 642
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http://www.waltermotorsports.com/v/Racing/afm/03afminside.jpg.html

I think it's the one on the left. Push the flap and you'll see.

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Muda Motorsports
"We're all here 'cause we're not all there."

cintibob
Member

Region: cfr
Car #: 13
Year : 1990
Posts: 105
Status: Offline
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I Can not find a company called ART I know I have heard of them before. When the time comes to get my afm done how do I contact them?

Andy Robottom Verified Driver
Member

Region: NW
Car #: 113
Year : 1990
Posts: 145
Status: Offline
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http://www.appliedracingtechnology.com/

Based in Austin TX, ask for Karl.

Thanks for all the assistance.

--------------------
....drive your own line

   

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