'99 S70 Starts but then quickly stalls

roy1956 · Post by **roy1956** » 03 May 2015, 11:42

I have a '99 S70 T5 with 70,000 miles which had been running fine. Today I went to start the car and could immediately tell that something was not right as I had to engage the starter for much longer than usual. When the engine finally started it ran badly for a second or two and then stalled. I tried it again and this time when it caught I accelerated up to 3500 rpm where it ran smoothly but then stalled again. After a few more attempts I decided it might not be getting fuel. So I hooked up a fuel pressure gauge to the schrader valve on the end of the fuel rail and it is reading 47psi which I think is normal. I wish I could tell you what codes it is throwing but I can get it to run long enough to get the CEL to come on. Any ideas?? Thanks!

Post by **abscate** » 03 May 2015, 12:41

Fuel pressure is ok.

Look for loose hoses in your induction air..if a turbo hose comes off the car will run poorly, if at all, often without codes.

When were plugs last removed and evaluated?
How many miles are on it?
Compression test is next step.

roy1956 · Post by **roy1956** » 03 May 2015, 13:12

appreciate the reply but perhaps I explained it poorly. Again, the mileage is only 70,000. The car ran fine just yesterday when I pulled it into the driveway. Now it won't start and stay running. It seems like it is starving for fuel is the best way I can describe it. Alternatively, or something just turns off the spark. The plugs are fine, certainly no change from yesterday. As far as compression, I doubt that anything happened overnight to cause a loss of compression. It ran fine up to 3500 rpm today but only for a few seconds then it was as if someone turned off the key. I feel it is some sort of ECM issue or something. I had the ETS recall done recently so I am pretty sure that is operating properly. I'm just out of ideas. Thanks

Post by **erikv11** » 03 May 2015, 14:19

These symptoms pop up out of nowhere all the time. Almost always it is due to a large vacuum leak. Check the intercooler hoses, and especially the hoses on the idle air control valve.

Start with visual inspection as what you describe sounds like what happens when there is a massive leak that is easy to spot (torn or loose hose), but it could also be one of the smaller lines and using propane or starting fluid to help you check is a good method too.

The car only has 70k but the rubber hoses have 16 years on them ...

Post by **abscate** » 03 May 2015, 19:57

No IDle air control valve on a 1999. It's very likely an induction leak though.

A valve or piston ring break is very sudden. On a 16 year old car, stuff happens.

I once chased a loose intercooler clamp for two weeks..car was undriveable. From the symptoms, you would have thought the engine was toast, very poor running.

Post by **erikv11** » 03 May 2015, 21:02

abscate wrote:No IDle air control valve on a 1999. ...

Oops, thanks.

Be on the lookout, I will likely continue to get that one wrong until I own or work on a 99 or later vehicle, and that may be a long time yet!

Post by **abscate** » 04 May 2015, 03:11

This makes the score

Erik 850
Abscate 1

Thx for all your help here.