MS2 Diagnostic Help Please

Fuel Supply & Ignition Systems

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Owen Snell
Posts: 38
Joined: Sat Sep 19, 2015 12:31 pm
Location: Gainsborough, UK

MS2 Diagnostic Help Please

Post by Owen Snell » Sat Jul 22, 2017 7:17 am

Type 4 with IDF pattern throttle bodies, MS2, crank sensor. I have had it in for oil cooler seals and not it's running bad / not at all.

Pig to start, spitting back through carbs. Once running, it wouldn't idle so tweaked the throttle stops and got an idle just above 1,000 rpm. Set off and in traffic, idle gradually rose then it died completely, just suddenly dropped off. Would not restart.

Stupidly, not got my laptop so can't check anything, although I should have it an an hour.

Any ideas for what might have been disturbed or what might have failed to cause this?

Owen Snell
Posts: 38
Joined: Sat Sep 19, 2015 12:31 pm
Location: Gainsborough, UK

Re: MS2 Diagnostic Help Please

Post by Owen Snell » Sat Jul 22, 2017 7:23 am

Had 20 minutes and fired. Idled nice for 20 seconds, then died. Seems like fuel, maybe more poop been stirred up in the tank and the filter is blocked. Showing good pressure at the injectors, just need to watch that when it dies as well .......

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ps2375
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Location: Meridian,ID

Re: MS2 Diagnostic Help Please

Post by ps2375 » Sat Jul 22, 2017 9:57 am

Dwell settings?

Owen Snell
Posts: 38
Joined: Sat Sep 19, 2015 12:31 pm
Location: Gainsborough, UK

Re: MS2 Diagnostic Help Please

Post by Owen Snell » Sat Jul 22, 2017 10:50 am

No settings changed since it was running properly, just the work on the cooler seals and remote cooler pipework. The thought now is that it's a fuel feed issue and nothing to do with the electronics. I was just assuming electronics but haven't really used it this year and fresh petrol in last week, so blocked fiter?

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Piledriver
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Re: MS2 Diagnostic Help Please

Post by Piledriver » Sat Jul 29, 2017 7:33 am

Pinched fuel line or return?
(if the motor was out perhaps)
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

Owen Snell
Posts: 38
Joined: Sat Sep 19, 2015 12:31 pm
Location: Gainsborough, UK

Re: MS2 Diagnostic Help Please

Post by Owen Snell » Wed Sep 13, 2017 7:13 am

Just to update / close this out.

The problem was lack of clearance between the crank sensor and the toothed wheel. No idea how long this had been going on (whether gradual over 5 k miles or knocked out of place when I got the oil cooler seals done), but the face of the crank sensor had a nice groove in it.

I tried replacing with a cam sensor I got locally and a 10k pull up resistor, but it died at 4,600 rpm. Another catalogue sensor just wouldn't work! Anyway, I ordered a new one and a spare from Mario (I am in UK, which is why this wasn't the first port of call) and sorted out the bracket in the meantime.

The bracket is a pig to work on in situ, as is fitting a replacement crank sensor. My engine builder had used a brass nut on the bottom bracket mounting and not the nuts supplied by Mario - he probably lost them. The brass nut had a domed face and was not fitted with a washer, so the domed face was engaging on the bracket. No surprise that this was not holding the bracket steady. The top mount was also not fully tight, but as this is a bolt rather than a stud, it is super hard to get anything onto the bolt head to tighten things up. In the end I chopped the head off a 13 mm ring spanner so it is now very stubby and managed to get that on the bolt head to tighten the whole thing up. A proper nut with washer was fitted to the bottom.

Even fully adjusted, there was not a lot of clearance between the sensor and the toothed wheel, so I got a local place to cut me some shims on their laser cutter from 1 mm stainless. These just drop in over the sensor body and screw when in place, so can be added as needed. One shim gave me the 2 mm clearance recommended.

The big issue fitting the crank sensor in situ is that it is very hard to get in place and, once in place, the fixing screw / nut / washer are really difficult to get fitted as access is so tight. For the final fit, I fixed the screw to the sensor with Devcon epoxy metal. This makes it harder to get the sensor in behind the bracket, but much easier to get the nut and washer onto the screw. The nut is also really hard to reach to tighten as the body of the sensor is in the way. The solution to this is a pivot head ratchet ring spanner with a socket adapter and 10 mm socket.

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