[jeroendo2]

Hi all,

My Saab 9-5 lost power during a mile then stalled. What I have done or know is;
- it now cranks but won't start
-swapped DI cassette, no help
-pushed fuel rail valve, no pressure
-had previously "check engine" warnings once in a while, and went off.
-sparkplugs visually look ok.
-sprayed brake cleaner in throttle body then cranked; no result, assuming also no spark.
- see vid; RPM meter moves but I'm not convinced CPS is workingRPM meter

- I read I can test CPS by reading ohm between 2 pins. I assume after disconnecting the connector? Do I need to remove CPS to test it or can leave it where it is?
-any other advice, apart from reading the computer?

Saab 9-5 2002 2.0t automatic

 

[jeroendo2]

No effective way to test CPS other than replace it. Can you hear the fuel pump buzz under the back seat when you turn the key to the on position? Do you get fuel pressure at the SchrAdler valve on the fuel rail?

Hi, no pressure at fuel rail valve. Will check if I hear it under the back seat. If I hear it it means pump works, and likely default CPS won't let pressure in rail ?

 

[jeroendo2]

Update: the fuel pump under rear seat zooms for a couple of seconds when turning the ignition on ( not cranking) However still no fuel at fuel rail valve. As I thought that it would run if I spray break cleaner in inlet and it didn't do anything I am getting confused, Did I saw someone writing; "if there is no fuel then automatically there is no spark"?
note; i measured 900 ohms at CPS that is a first good sign but no guarantee I have already understood. Tomorrow will swap spare key which has no alarm function with original key.
So main question; Does Saab 9-5 give no spark if no fuel?

 

[jeroendo2]

That is not accurate. The pump only primes once every X hundred seconds. I don't know what that is, but I think it's 5 or 10 minutes. If you keep turning the key off and on, it will only prime once.

Should the fueling valve only spray strongly when cranking, or without cranking, just ignition on, is enough?

 

[jeroendo2]

What you are suggesting is not a good test. You really can't understand what is happening without a fuel pressure gauge.

If the car has been sitting for a little while, you turn the key, the pump runs for about two seconds, and then you IMMEDIATELY depressed the valve on the fuel rail you should get a spray of fuel. But, that only happens if everything is working correctly - fuel pressure regulator, check valves, etc. - and there is no certainty that's true.

I would really encourage you to buy, rent, or borrow a fuel pressure gauge. They are typically not expensive.

If you are sure you can't get a gauge, then this is what I would recommend:

1. After the car has been sitting a while, turn the key and let the pump prime for 2 seconds
2. Depress the valve on the fuel rail and release any pressure that's built up
3. Crank the car over for 5-10 seconds
4. Depress the valve on the fuel rail and see if there is pressure

If yes, the pump and CPS are probably working
If no, then either the pump or CPS are not working

Then,

1. After the car has been sitting a while, depress the valve on the fuel rail and release any pressure that's built up
2. Use a jumper wire to run the fuel pump directly from the fuse box for 5-10 seconds
3. Depress the valve on the fuel rail and see if there is pressure

If yes, the pump is working
If no, then the pump is not working

I DO NOT recommend doing this. Releasing pressurized fuel into the atmosphere is a good way to start a fire. You should use a fuel pressure gauge. Continuing without one is dangerous.

Thanks for your time and effort, I'll test tomorrow and give an update.

 

[jeroendo2]

What you are suggesting is not a good test. You really can't understand what is happening without a fuel pressure gauge.

If the car has been sitting for a little while, you turn the key, the pump runs for about two seconds, and then you IMMEDIATELY depressed the valve on the fuel rail you should get a spray of fuel. But, that only happens if everything is working correctly - fuel pressure regulator, check valves, etc. - and there is no certainty that's true.

I would really encourage you to buy, rent, or borrow a fuel pressure gauge. They are typically not expensive.

If you are sure you can't get a gauge, then this is what I would recommend:

1. After the car has been sitting a while, turn the key and let the pump prime for 2 seconds
2. Depress the valve on the fuel rail and release any pressure that's built up
3. Crank the car over for 5-10 seconds
4. Depress the valve on the fuel rail and see if there is pressure

If yes, the pump and CPS are probably working
If no, then either the pump or CPS are not working

Then,

1. After the car has been sitting a while, depress the valve on the fuel rail and release any pressure that's built up
2. Use a jumper wire to run the fuel pump directly from the fuse box for 5-10 seconds
3. Depress the valve on the fuel rail and see if there is pressure

If yes, the pump is working
If no, then the pump is not working

I DO NOT recommend doing this. Releasing pressurized fuel into the atmosphere is a good way to start a fire. You should use a fuel pressure gauge. Continuing without one is dangerous.

Today a rainy day, wil check tomorrow, one thing got me curious; it seems you say if CPS doesn't work you won't get pressure at valve nor during the 2 seconds when pump starts up, nor when cracking, correct? Or would it be; with bad CPS ( and working pump) you get pressure at valve for the 2 seconds startup, when turning on the ignition, but then will fail to booster when cranking?EDIT: sorry I see jvanabra already mentioned, thnx

 

[jeroendo2]

You could have replaced the CPS numerous times by now, why are you reluctant to do so?

It's a relatively cheap part and a very easy job.

I am on an island, with no easily parts to get and the car is on the side of the road stranded, not at my house, and its raining :-( Besides that I have another car and trying to understand is a hobby too. The CPS has all signs of being well ( RPM moves, ohms correct) So with the question if it should build op fuelpressure at valve even if CPS is dead, if the answer is yes I know its the fuelpump, as for sure I don't have pressure there without cracking.

 

[jeroendo2]

Hi thanks for all advice, I realize I am not going the quickest road for some, I am not that much in a hurry, and in the end I will get my parts.
Today I 've put a test light on the fuse for fuel pump. It gets power when turning the ignition on, then goes off. Then when crancking it goes on again; CPS seems to do it's job. Then putted a 12v direct from battery to this fuse as one of you suggested; the pump is hearably working but when pushing the valve at rail right after doing that; still no pressure; So bad fuel pump or clogged filter. The only thing I don't get; why doesn't it fire up after spraying starting spray?

 

[jeroendo2]

Where are you spraying starter fluid?

On top of the throttle body. Either I took off the black plastic hose or I opened the not used vacuum connection with red ring, also right on top of throttle body.Then sprayed 3-4 seconds.start

 

[jeroendo2]

Can you post a video with sound of it cranking?

start

 

[jeroendo2]

On the surface, this sounds like a failed fuel pump. However, as I mentioned before this is not conclusive. If the check valves on the fuel pump are not working it's definitely possible you would lose rail pressure before releasing the Schrader valve. If you have a fuel pressure gauge attached, while the pump is running, you will know for 100% certainty if you have fuel pressure.

An alternative approach, which I would also not recommend due to extreme fire risk, is to detach the return from the fuel rail (the smaller of the two tubes), slip some fuel-safe hose over the rail, and direct those hose into a container. If you crank the car and gas fills the container, the pump at least somewhat works. Of course, without a fuel pressure gauge you don't know if it's enough.

In any case, it sounds like the CPS is working. I would probably cross that off the list as a suspect. You seem adverse to buying tools, but connecting a noid light to a fuel injector connector would rule it out entirely.

Hi yes you are right, a fuel pressure gauge would be quicker, I'll start it tomorrow with a friend while I am depressing the valve to rule that out, thanks. checking out now noid light.

 

[jeroendo2]

start
Should be public now

 

[jeroendo2]

UPDATE: i checked compression and it doesn't look good; see pics; 3 cilinders at 3 bars and one at almost 6 bars.
I have checked the return fuel line by taking the rubber hose away at tank; fuel coming out, not spraying miles away and checked fuel rail valve while cracking; quite some fuel coming out but again not spraying me all over. But I am afraid it doesn't matter if the engine is done we'll likely have an R.I.P. Saab.
For the record I tested compression at

my other car Alfa Spider and it measured 7 bars. So even if the tool is measuring low I am afraid there is something really wrong, maybe explains why it didn't ignite when spraying starter spray.

 

[jeroendo2]

Are you sure the battery is good? If the battery is discharged you will see low compression numbers. Low compression on three cylinders is quite unusual. Did you see 6 bar on the first cylinder you tested and 3 bar on the remaining three?

hi yes cilinder number 4 (closest to drivers side, LHD) was higher the rest low. I was jumpstarting it wit another running car for the compression test, and pushing the throttle pedal.

 

[jeroendo2]

You have nothing to lose by removing the valve cover and checking valve timing (compare cams' positions relative to crank mark at TDC). Although uncommon, timing chain may have jumped a tooth which could explain compression issue. If so, it may be moot if valve(s) made contact with piston(s) since it's an interference engine.

Interesting point, thnx

 

[jeroendo2]

Thanks, it is 2 years older now then the picture, it got a bit less shiny. The one who drove it reported overheating but no red lights, so I didn't put too much attention to it, I saw a leak at radiator. What if I do focus on that.. Couldn't it be that cilinder number 4 gets to be cooled better or till the last end and the others don't?It is closest to the thermostat and radiator hose..Therefor the other 3 piston rings went bad, and number 4 didn't? Just thinking out loud. Then is there a reason to figure out why the petrol rail does what it does ( low pressure and won't keep it ) because of overheating? A constantly leaking injector for example?Cilinder 4 had a wetter sparkpkug then the others, but not soaking.

 

[jeroendo2]

Hi all, latest update: the fuel rail valve turned out to be leaking. Screw in a new one and bought a fuel pressure meter, nicely at 3 bar. Then bought an other compression meter to doublecheck the compression; was still very low at 3 cilinders (3 bar only) and just bad at cilinder 4. When adding some engine oil in the spark plug opening compression doubles. Then checked timing ; all good. So the conclusion ( I think ) is; low compression, must be because of overheating, The driver who drove it told me no red lights for overheating, but well I wasn't there. Not decided what to do.. is this likely "only" changing piston rings or can throw away whole engine..?

 

[jeroendo2]

Have you done a pressure test of the cooling system to see if the head gasket is leaking?

Buy a kit that analyzes the coolant to see if there are combustion gases in it.

Thanks,
The coolant got all drained because of a leaking tap in the radiator. My guess is that if it first drives smooth and then within 3 miles stalls its not so likely the head gasket blows for 3 cilinders at the same time. Taking of the head would be next step; if I'm still in for it.

 

[jeroendo2]

See my thread “Time to Pressure Test for Elusive Coolant Leak” from about 10 days ago And follow what I did to diagnose what is going on. So text step is to pressure test coolant system to see if it will hold pressure. Then, if the engine will ru, as Bob suggests, test the coolant bottle for exhaust gases. Next, and this is optional, get a boroscope (I bought one recently for $50 US, and look down the spark plug holes under various conditions and see what you see. Next, do a cylinder leak down test. That will tell you where you are losing compression. With all that information you will know exactly what is wrong with your engine and then be able to make a well informed decision of what direction to go.

Great tanks, need to tell you car isn't running, and its leaking through radiator, but still helpful, thanks!

 

[jeroendo2]

Update: took the head of, measured the head and its warped.