turbo cuts out problem? 940/ 1991

hi
and many thanks for the replys , it took me a while to get back on line because of the inlog codes . i have had all the cables spark plugs etc replaced a year ago and the problem persists . but now i have driven for the last too weeks without any trouble, that is what is so frustrating , the car runs beautifully now but i am sure in a month or so it wil do the same thing , cut out ,start thumping along or start thumping along on half burnt petrol on what seems like a couple of cylinders . it is like it gets a strange message from the board computer. when tis happens the turbo guage seems to be locked on high . i will check the codes ..thanks again for the replys en het mag ook in het nederlands .
groeten bob

running on only 2 cilynders and a strong gasoline smell could have 2 reasons as i think about it:
- no ignition (due to bad rotor, spark plugs, cables etc or bad signal from rpm sensor)
- to much gasoline (due to bad injectors, or bad working ignition system (ECU, fuel pressure regulator, bad (loose!) ground connections)

what were the conclusions of persons who looked at the problem ? are there any parts renewed ?

maybe a foam sheet on top of the air filter sucked into the tube to the engine ? 

Welcome, Bob, nice (full-)lastname you have, by the way.
Anyway, I assume the 91 cars have a pigtail diagnosis-box on the frontleft strut-tower.We have a rather extended number of pages, to figure out errorcodes in your car, but in dutch only.You wrote, that that won't be an issue, so here is the link: <a href="/node/12449">Overzicht storingscodes voor 700 en 900 serie.</a>Use the foutcodetabel, for your car.
Have you checked the sparkplugs, cables and distrubuter yet?My guess is that your car has al Hall-sensor as well, sometimes causing problems.Look for hall in the search box in th etopleft corner of this site, see what it comes up with.
Your car has a fuel-pump relay too, in the relaybox, behind the ashtray under the radio. Look for the white relay, try to open it, and inspect it closely to see if any contacts on the print are corroded or cracked.
Doe that happen on-the-run or only when starting.Only on cold start, or at warm-start as well?

henk 940LPT schreef : maybe a foam sheet on top of the air filter sucked into the tube to the engine ?

I see I have  to get to a typing course, to learn to type faster......
Anyway, that foam layer, when it gets sucked in the ait-inlet, woulnd't it obstruct the airflow continuously, and not, as described, randomly? 

Baseman schreef :

henk 940LPT schreef : maybe a foam sheet on top of the air filter sucked into the tube to the engine ?

I see I have  to get to a typing course, to learn to type faster......
Anyway, that foam layer, when it gets sucked in the ait-inlet, woulnd't it obstruct the airflow continuously, and not, as described, randomly? 

That problem will cut off the airflow, it means the engine will cut off on high rev's.
I experienced that problem and it only occured while i accelerated fast end the engine rev'ed up to over 3500 rpm.
But its worth a check, remove the mass air flow meter and check for a free airway.

We've seen a car that cut out on high power only because the foam got sucked against the LMM mesh, when low power it would fall down again.
Is the 2 cylinders definate? my association with 2 cyls would be a problem with the powerstage in the ECU driving the injectors. It does that 2 by 2. Maybe bad soldering points on those in the ECU?

This idea doesn't match, in my opinion, with the fact that the car has an unburnt petroll smell.
If it's for sure the engine does run only on 2 cyllinders, and not on 4, I would say it's an ignition problem.

If you get the chance to test if the engine runs on 2 by pulling leads from the plugs or the injectors I suggest you do this to be sure. This is the way to discover if it's not a different problem what looks like an engine not firring properly on all four.