SaabCentral Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter · #1 ·
My repair shop's telling me that in order for them to properly evaluate why my car (a 1994 900S) failed emissions, they will need to replace what they're calling the "Electronic Control Module", and they're quoting me about $900 new. The story is that they can't get the check engine light to flash in any kind of sequence.

The Saab indie that scanned the car with an ODB I was able to get readings, none of which seemed to have anything to do with the check engine light (EVP valve and camshaft alignment were the results).

Anybody know what's going on?

Right now, the oil's getting changed.

My symptoms are this:
  1. Smell of fuel in the cabin while driving
  2. Check engine light remains on all of the time
  3. Failed emissions due to Hydrocarbons and NOx
  4. Dashboard panel is glitchy (lights go off/get brighter and gauges respond etc.)
  5. MPG of about 14 - 15 with mostly town driving
I'm having a heck of a time knowing what to do, here, and any help is appreciated.

- sG
 

·
Registered
Joined
·
803 Posts
You almost definitely have a fuel leak. Check all of your lines, I guarantee that you're going to find a wet spot.
The leak would likely cause the car to run lean, and I think the CEL will come on if the car's running too lean. It would also explain your failed emissions
 

·
Registered
Joined
·
1,388 Posts
Cliche` said:
You almost definitely have a fuel leak. Check all of your lines, I guarantee that you're going to find a wet spot.

The leak would likely cause the car to run lean, and I think the CEL will come on if the car's running too lean. It would also explain your failed emissions
I don't believe there is a "fuel leak", he already stated there is a code present for an EVAP problem, this is the system that recovers fuel vapors so that they can be stored and routed to the engine at certain times to be burned with the normal combustion process.

Too lean a mixture on an emissions test would be shown as a very low HC & CO reading, while having a very high NOx reading, the combustion chamber temperature is very high from the lean mixture causing the NOx to increase.
S.Gecko said:
My repair shop's telling me that in order for them to properly evaluate why my car (a 1994 900S) failed emissions, they will need to replace what they're calling the "Electronic Control Module", and they're quoting me about $900 new. The story is that they can't get the check engine light to flash in any kind of sequence.

The Saab indie that scanned the car with an ODB I was able to get readings, none of which seemed to have anything to do with the check engine light (EVP valve and camshaft alignment were the results).

Anybody know what's going on?

My symptoms are this:

Smell of fuel in the cabin while driving
Check engine light remains on all of the time
Failed emissions due to Hydrocarbons and NOx
Dashboard panel is glitchy (lights go off/get brighter and gauges respond etc.)
MPG of about 14 - 15 with mostly town driving
I'm having a heck of a time knowing what to do, here, and any help is appreciated.
Before you go a authorize an ECM change, get the car scanned by another shop and compare the results. Not all OBD scanners are the same, some can't read certain cars, or some can but can't clear the codes. Try different scanners or a different shop.

But the codes that were present as you stated above can and will effect emissions results, as strange as they seem. EVAP is an emissions control component, and the Cam alignment issue can through off the Hydrocarbons, its all related believe it or not, it just may be out of your current mechanics leigue. Emissions related issues are not every mechanics specialty, many don't know how to fix these problems without just replacing everything.

Trust your car, if the OBD scans are coming up with sensor problems and EVAP issues, fix them first, then give it a few days to see if the light comes back on, then try emissions again. Work systematically, don't fix too many things at one time, fixing one thing might through off another thing or cause another problem that you can't backtrack to see what caused it.

EVAP issues can cause the smell of fuel in the vehicle, there is a carbon canister located behind the passanger side front fender that holds and stores all these fuel vapours until the engine management system decides when an appropriate time to release them into the intake manifold can take place. there are hoses and check valves and control valves that regulate this process. you need to check these lines, valves, ect.

I'm wondering why you have a camshaft alignment issue or similar as you stated above. Did you have top end engine work ever done?
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #5 ·
Thanks for the great advice.

I had my current mechanic check the fuel lines when they did the oil change and will find out what -- if anything -- they found out when I pick it up.

I'll bring it back up to the indie shop this weekend, I guess, and have them do an eval base on their scan.
 
1 - 5 of 5 Posts
Top