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Discussion Starter · #1 ·
I've got an Intermitant problem with the engine cutting out for a split second when accelerating hard.

I had a new DI cassette fitted a couple of weeks ago, as I was having the above problem plus rough running & poor fuel consumption.

The car has run alot better, but It still cuts out when I give some welly. There's some Abbott bit's fitted, ECU,Intercooler etc, but I've had all of these bits for a while.

I had the boost pressure checked when the DI cassette was fitted & It's running at 1.2Bar which I was told was okay.

Anyone got any Idea's as to what's up with It?
 

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Overboost cutout is most likely. I'm running 1.15 bar and get it if I'm too quick opening the throttle in the midrange of rpm. If you are running a MBC, turn it down a touch (to 1.1 bar).
Nick.
 

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I had a similar problem a while back but it was my air mass meter that was doing it. I'm pretty sure you've got a MAP sensor instead. I'd suggest checking out the lambda sensor and fuel filter to start off with. Any check engine light?

Edit : take cdcarlson's advice if theres no check engine light
 

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Originally posted by Gary N:
[qb]I've got an Intermitant problem with the engine cutting out for a split second when accelerating hard.

I had a new DI cassette fitted a couple of weeks ago, as I was having the above problem plus rough running & poor fuel consumption.

The car has run alot better, but It still cuts out when I give some welly. There's some Abbott bit's fitted, ECU,Intercooler etc, but I've had all of these bits for a while.

I had the boost pressure checked when the DI cassette was fitted & It's running at 1.2Bar which I was told was okay.

Anyone got any Idea's as to what's up with It? [/qb][/b]
I'm taking a guess that you've got cold weather right now?

I suppose when these items were fitted (the performance stuff) that it may have been a bit warmer (less cold air = less oxygen dense air = less bang from air intake).

The old DI and plugs weren't probably giving the spark or sensing that they should have been and now renewed, combined with the nice cold air, you're probably getting more boost than you should be.

If you aren't running an MBC or something, the car will likily adapt the boost down to stop overboosting in light of these changed circumstances. This will happen over time or you could do an adaptation run (search for "adaptation run" on this forum for details). If you are running an MBC, you should dial it down a little.
 

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Could be a sticking wastegate actuator rod worth having a look at, they do get crudded up and need cleaning have a look at BillJ website it shows you where it is. Good luck www.saab.info
 

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Discussion Starter · #6 ·
Cheers for help guys
,

I'll do an adaption run first & see If that sorts It out. If that does'nt do the trick I'll get the Lamba sensor looked at & I guess It could also do with a new fuel filter as It's done 77K now.

If I have no luck with all that I'll wind the boost back a bit as I've got an MBC fitted.

On the subject of MBC's, I recently emailed Maptun about a Stage 4 or 5 upgrade.


I listed my car's spec & Maptun replied & mentioned that a MBC valve was very dangerous
for the engine & that I should remove It, as there Is no knock safety. As anyone else heard that before?

My MBC Is an Abbott one & apparently It has an overboost safeguard, so I guess It should'nt cause any problems.
 

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Originally posted by Gary N:
[qb]Maptun replied & mentioned that a MBC valve was very dangerous
for the engine & that I should remove It, as there Is no knock safety. As anyone else heard that before?[/qb][/b]
Yes, it is correct. However many, many people run them without any problems- as long as they don't try to turn them up to high!
 
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