[pva]

A natural progression from "missing"....

Over the last 2 to 3 weeks my 9k sounds and feels rough on idling, even when at operating temp, and particularly in Drive. Idles at 900-1000rpm. Occasionally a bit jerky on smooth acceleration from standstill when cold. Reasonable acceleration on open road, but not quite as perky as before. No unseasonable smells from engine compartment. Battery A OK.

Suspicions lean towards DI unit. My car goes for it's 120 000 km service at a non-SAAB specialist (remember, we're at the end of civilisation!) Will mechanic have the wherewithall to make the diagnosis?? Does he need a replacement DI unit to compare, or are there other tests available? Have already warned them to have NGK plugs at hand.

Your opinions much appreciated.
9000CD '93 auto 2.3 non-turbo
Cheers

 

[WindyH]

Before you commit to a new DI unit, check all the pipes that connect to the inlet manifold or crank case. These often go brittle in time which can cause them to split. My experience of DI problems is that the engine will usually missfire, under acceleration. You don't mention that your engine is missing (so to speak)

 

[pva]

Thanks for the advice, WindyH. When last opened bonnet, engine seemed very present. Will check all pipes first. Indeed, car does NOT miss on acceleration or at speed.
Cheers

 

[Paul D]

Try a bottle of STP injector cleaner (or similar).

It will resolves rough idle if due to injectors getting clogged - which is a common problem on high miles.

 

[pva]

Car serviced. New plugs replaced the incumbents, most of which revealed a pitted 1.9mm gap!! Still somewhat rough idle, especially in D, but goes like the proverbial clappers with the foot down. Can hardly believe that these wee cylinder electrodes can give me 10-15% extra power again!

Cheers, in safety et cetera