Mystery Inj firing

For discussing injector selection,manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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Juliemac
MegaSquirt Newbie
Posts: 16
Joined: Fri Jan 13, 2006 4:29 pm
Location: Up State NY

Mystery Inj firing

Post by Juliemac »

A freinds MSII system can start out running well, but intermittently foul up.
Opening the hood, he says he can hear the injectors triggering.
I was thinking it was the load on the MS board, but....
Using a new, seperate MSII and relay boards, the car ran perfectly, then did it again.

Since the main board and the relay board have been changed as well as the coil and distributor, that leaves very few components.

Air temp, water temp and the cable between the 2 boxes.

What6 else can we check?
1981 VW Scirocco w Turbo 2L 16v
Juliemac
MegaSquirt Newbie
Posts: 16
Joined: Fri Jan 13, 2006 4:29 pm
Location: Up State NY

Re: Mystery Inj firing

Post by Juliemac »

Ok 2 years ago my map sensor died causing the MS to read 100 kPa at all times.
This flooded the engine immediately.
Could a vac leak cause similar problems?
1981 VW Scirocco w Turbo 2L 16v
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: Mystery Inj firing

Post by Matt Cramer »

A vacuum leak in the MAP hose itself will cause too much fuel, but not the injectors themselves firing. A vacuum leak anywhere else will only cause a higher idle. Do you have a data log of the problem happening you could post?
Juliemac
MegaSquirt Newbie
Posts: 16
Joined: Fri Jan 13, 2006 4:29 pm
Location: Up State NY

Re: Mystery Inj firing

Post by Juliemac »

I'm in NY, my friend is in Tx. Long distance trouble shooting :)
I asked him to make one. Hope to see it tonight and I'll post it.
1981 VW Scirocco w Turbo 2L 16v
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