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Aloha SC, Having issues with my '95 900, 2.3L, non-turbo, 5speed, and hoping for some suggestions. Here's the rundown: (No CEL or codes), it started missing at idle, but running, then Sputtering and stalling if I accelerate at anymore than a crawl. R/R fuel filter and MAF with no improvement. R/R spark plugs/wires and driveability improved, but still rough idle. Found and fixed 1 definite and 1 possible vacuum leak at base of plenum. I also found the O2 sensor (which looks new) plug connector broken, showing the wire ends, so wrapped it with tape to seal and reconnected.

And now the idle is smooth, but forget any acceleration with the car in gear and moving.
I have a new CPS, but haven't replaced due to previous owner replacing all sensors about 20k miles ago.

Where should I look next? TPS? I can't tell if it's fuel or spark starvation.
 

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Try pulling the o2 sensor out, if it improves start looking at an exhaust blockage, could be a clogged cat... You should get a reader on it and check your fuel trims first to see if you got all of the vacuume leaks, trim reflex will tell you if the pump pressure is weak.
 

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Try pulling the o2 sensor out, if it improves start looking at an exhaust blockage, could be a clogged cat... You should get a reader on it and check your fuel trims first to see if you got all of the vacuume leaks, trim reflex will tell you if the pump pressure is weak.
Thanks, Robert. If you can tell me what kind of reader I can use for the 1995, I'd appreciate it. So far no luck on that front.

I'm leaning toward, and ordered, the fuel pump. Due to recent intermittent fuel gauge readings, I'm gonna have to pull it soon anyways. To be sure, I'll also change the fuel pressure regulator, TPS, and O2 sensor.

The motor screams fine while parked, but try to put it in gear and it sputters and spits and balks until the clutch is pressed...no load.

I'll update once those things are done in about a week.

Any other ideas from anyone are appreciated!
 

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That's what I understood. However, I had a local Saab guy try his Tech2 and it wouldn't read. After contacting the mfr they said they do not have a chip which reads the early, transitional '95s. I'm left scratching my head.
 

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The Tech II needs a version 44.000 (if I recall) card. It then should read a 1995 900 no problem. I've used that card on an earlier 9000 with the ISAT plug, and of course on my departed 1997 900. The common 148.000 card won't work, of course.

Does it feel like a sharp cutoff, or jerking and spluttering? If the former, I'd continue investigating the ignition. If the latter, is your tailpipe all black with carbon? What condition were the old spark plugs in?

I do agree that the Tech II is the way to see if the various ECU sensor signals are good.
 

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I'm agreeing there's a good chance that you've got a clogged catalytic converter are you upwards of 135000 miles with an original pipe. I just dealt with this and I've seen it before. The car will get moving but as soon as you try to give it any gas and get it upwards at 25-30 miles an hour there's nothing. If you walk around to the front of the motor after turning it on and driving it for a short period of time you can feel the heat coming off the beginning of the exhaust down pipe. The crossmember bar that goes from side to side above the radiator if you try to touch it it should be extremely hot way too hot for normal operation that's a very quick and easy way to determine you got a clogged cat. Just be careful because that kind of heat can very quickly destroy other things in that area is going to heat up your transmission fluid. Heat can destroy a car very quickly. Good luck.
 

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Discussion Starter #8
EDT: At the time of my research a few months ago, I couldn't find one so gave up. Anyone know where I can get a Tech2 with a 44 chip?

Definitely a sputtering and jerking. The old plugs were a little black. The tailpipe has a some carbon, but I was attributing that to when I was turning the engine over with no spark leaving unburned gas smell at exhaust. Then engine running burning all of that out of the system.

Minirex: I guess I'll pull the O2 sensor today while waiting for the new parts (we have to order everything here in HI) to see if there's a difference and I'll check the heat in engine as I didn't notice it was extra hot. The air pump is making a "hoover" sound for several secs at startup, not sure if that is an indicator of anything.
 

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Im going out on a limb and guessing the vacuum leakes you plugged threw off the fuel ratios and clogged the cat, running rich b/c of the air leak under boost. Just a guess, no holiday in last night. Evidence being coked tail pipe and plugs.
 

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I'm agreeing there's a good chance that you've got a clogged catalytic converter are you upwards of 135000 miles with an original pipe. I just dealt with this and I've seen it before.
Then again, I drove my 2.3 non-turbo to 392,000 km (just short of 250,000 miles) on the original cat. And last summer I had some ignition-related severe misfire issues (that don't sound like the OP's problem) which didn't do the converter any good, so that I was getting P0420 codes weekly, and other than the codes, the car ran fine, right up to the 6400 RPM fuel cutoff.

I also had a non-Saab with a plugged exhaust system. It didn't quite run as the OP described. And it idled just fine, which is not the case here if I read correctly.

EDT: At the time of my research a few months ago, I couldn't find one so gave up. Anyone know where I can get a Tech2 with a 44 chip?
I have one, but that doesn't help you. They should not be impossible to find.

In the meantime, it does sound like it's running rich. I would maybe verify that the fuel pressure regulator is hooked up correctly and working fine. I would also check the temp sensor used by the ECU to make sure that the wiring isn't frayed. (On these cars, the temp gauge runs off a different sensor.)
 

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A clogged cat can cause misfires as well as map sensor codes .everything is backing up in to the engine causing all these problems .its possible a partially clogged cat may have been part of the problem .some times especially if raw fuel has been dumped into the cat the honeycomb will break apart giving some relief but hind sight is 20 /20 and often later on we figure out that there was a lot more to the problem than first thought.just something to consider.
 

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You can download the 44.000 bin from the Tech2 forum on this board. Use tech2cardwriter to write it out to a Tech2 connected to a PC via serial cable.
 

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Robert S
OP's car is na

I had a problem just like this with my BMW 635CSi.
It happened after I drove through about 6 inches of flood water (it's very low).
It was the O2 sensor. Try disconnecting yours to see if it makes a difference.

Minirex4777
The best way to test if a cat is blocked is to attach a pressure gauge to the O2 sensor port and measure for back pressure. No matter what your grandfather told you, back pressure IS NOT good. About 1 psi is the max.
If pressure shows up you'll have to take the cat off and inspect it.
If the monolith is loose or slagged, it's cooked.
If it all appears to be in one piece just dirty and clogged it can actually be washed with soapy water. Sounds silly but ask the internet, and Scotty Kilmer says so too.

It still might be the plugs.
My NG900S na 2.3 doesn't like NGK Iridiums for some reason. I replaced them with the cheapest on the shelf, Bosch which I stopped using 20 years ago, and away it went.
I know the DIC doesn't like Iridiums.
It would also drive bad if the airbox on the throttle body wasn't sealed down tight.
 
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