Megasquirt help!!

stevieturbo · Post by **stevieturbo** » Wed Jun 11, 2014 6:58 pm

googling finds some traces and info here

http://ls1tech.com/forums/pcm-diagnosti ... scope.html

http://www.msextra.com/forums/viewtopic ... 8&start=40

volospian · Post by **volospian** » Wed Jun 11, 2014 7:08 pm

Just bypassed the relay and tried firing it up....... it works, although the tune is a million miles off and it idles at about 3k, so I didn't run it for long, only 30 seconds or so.... still, if I can get the base tune sorted and get the freaking relay working I should be about there!

stevieturbo · Post by **stevieturbo** » Wed Jun 11, 2014 7:10 pm

Just because it starts and runs, do not for one second assume the trigger setup is correct.

Check ignition timing at a couple of different rpm's, and different timing figures to ensure it is doing what it's supposed to be.

ie with a timing light.

DaveEFI · Post by **DaveEFI** » Wed Jun 11, 2014 11:30 pm

volospian wrote:Oh I do not fekking believe this... I thought I'd try and start it up, but now the fpr is not working. It was fine last time I connected it.

If I ground 85 manually, it comes on, pump runs, etc.
If I go into test mode, connect the multimeter between the fpr wire and a 12v feed, go into test mode and click "pump on" the voltage goes up to 12.5v and drops to 0v when I click "pump off".
However, when I click "pump on" and connect the fpr wire to pin 85 the voltage drops to 0v and the relay stays dead.

I thought the fpr was a switch to ground? When I ground the relay manually it works so it's not a duff relay, and when I just test a route to ground on the fpr it shows voltage... it just won't drive the relay any more. This was working before I started f*^king around with the ms.

Arrrgggghhhhhhhhhh........

First, don't rely on a voltage reading taken with no load. All measurements should be taken with the relay connected.

I've not looked at your particular software, but the norm is for the pump to run for a couple of seconds at switch on - then only start again when MS sees a reliable tach signal.

IIRC, you can adjust how long the pump runs at switch on in software - or disable it totally. It's quite possible it is disabled in a test mode to prevent fuel being injected to a stationary engine, but that's only a guess. But if you try it again not using a test mode, does it run for a short time at switch on?