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Discussion Starter · #1 ·
I just ran through a bunch of stupid things going wrong with my car, and have eliminated a lot of stuff like IAC, CTS, IAT, MAP, and new battery. No codes coming up now either. However, the last two days I've had a random sputter and once even cut off while I had my foot on the gas. A couple times it just pushed past the dead spot and caught up to where it should have been. The other time just cut off entirely while driving at about 40mph. I'm not sure of the age of my fuel pump, but I should have another on the way at this point regardless. Anything else besides the pump I should check? CPS? As stated prior, there are NO codes to speak of. Can't think of what else it might be, and not wanting to throw money at this right now either.

BTW its a 98 900 SE
 

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Sounds similar to the occasional problem my car has. How new are your spark plugs, and what are they gapped to? Is your car tuned at all? My car will lurch when the boost gets above about 15 psi or so...the problem had gone away but now it's back, so I'm going to change plugs.

Also do what PimpMyPc said.
 

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Discussion Starter · #5 ·
1. DIC is good, or at least doesnt throw a code. My other one throws a misfire code, but seems to run well otherwise. Perhaps I'll toss in and see. The misfiring one never ran rough, just tossed a code.

2. Plugs get changed every 3 months or so. I'm a nerd about that. These have maybe 1000 miles on them, if that. Gapped to spec.

3. Car is not tuned.

I'll swap the DIC and see if I get the problem on my way to work today. Will report back.

Also realized why I couldnt find this thread again, since I posted in Performance instead of Problems. D'oh! That's what happens when you don't pay attention. Feel free to move this if needed.
 

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My friend has an '89 BMW 312 something or other and his car would fall flat on its face at 4K rpms and then kinda go past that, after he changed his engine ground strap all was good, just saying check the cheapest/easiest first (not to mention simple) first ;)
 

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Discussion Starter · #8 ·
Well, I tried to figure out what was going on with it today, and here's what I found. I swapped out the DI cassette, with a known good one, and until the car really got heated up, nothing was out of the ordinary.

My commute to work is at most 30min, and that's on a bad day. Drove as normal this morning. Fired up to go out and drop money to a person who I will be renting from soon, and they're a little further out than my usual commute distance. Once I headed back (total drive time round trip was a little over an hour, more than enough time to get the car really warmed up) the thing started falling on its face at mid range rpm.

Idling is perfect, WOT is fine too. It's in the 1500 to about 3500 rpm spot that it will just fall off, and actually shut off twice on me. One of which required pulling off and letting it sit for a second, then it fired up. I had a CPS go back on a Cherokee a few years back, and it exhibited the same symptoms after a decent amount of driving. That was a real pain to track down at first, since I knew nothing about that then.

If it were a fuel pump issue, I would think this would be a problem at anything past idle, and certainly not allow me to go WOT with no problems. It's once it is in a normal range that things get nasty.

Anyone in the DC area got a spare working CPS I could try/buy off you, rather than wait 3 days for eeuro to ship? Or any other thoughts?
 

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Discussion Starter · #9 · (Edited)
Not that it matters, but so some NOOB doesnt try to tell me its the purge valve when it isn't, I have a new one in there too.

Also the sputtering/stalling/shutting off is intermittent, but got worse the longer the car was driven. So when its cold, and up to about 30min or so, I can't tell that anything is wrong with it. Really thinking it must be the CPS just getting hot and shorting at that one spot.

Not going to assume thats it just yet, so I'll wait and hear what any of the older and wiser (at least in SAAB time) among us have to say.
 

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Discussion Starter · #11 ·
Do you have a fuel pressure gauge? I'd try to rule that out. You could hook one up and feed it up to the cowl and watch it while you drive perhaps.
I do have one, somewhere in a box of random car shit. Guess I'll need to dig that out. Although that does seem odd that the pump would start to act up after driving for about an hour, but be good for short trips. What should I be checking for as far as pressure goes? Also, what should I look for as far as numbers from CPS?
 

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I don't know about the CPS, but I'd look for a steady 45 psi or so of fuel at all times. I was thinking that perhaps the return regulator is flaky too and could cause a real rich condition that could flood the motor.
 

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Discussion Starter · #13 ·
I don't know about the CPS, but I'd look for a steady 45 psi or so of fuel at all times. I was thinking that perhaps the return regulator is flaky too and could cause a real rich condition that could flood the motor.
This probably sounds dumb to you, but where is the return regulator? Part of the pump? If so, good, since I have a replacement coming. If not, how the hell do I test that, if its even possible?
 

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This probably sounds dumb to you, but where is the return regulator? Part of the pump? If so, good, since I have a replacement coming. If not, how the hell do I test that, if its even possible?
Not dumb. The fuel system has a return. The pump supplies more fuel than is needed, and the excess is returned to the tank (two lines, one in, one out). The regulator is in the middle of the two lines, on the fuel rail (where the injectors are). The regulator is a "restriction" in the line, so that the pressure will remain constant on the supply side.

I think the regulator in you 9-3 will also be connected to vacuum source. This is to get a varied "restriction" to vary the fuel pressure. I've seen some of those regulators fail, and provide too great of restriction (too much fuel to engine causing a rich condition) or of course too litte. I've also seen the vacuum diapram in the pregulator fail and allow fuel to be sucked into the engine through the vacuum.

The gauge will connect to the fuel rail (there is a schrader valve or similar). If you verify a constant pressure, that is steady, your good. You should also rev the motor while the gauge is connected and see if you can see the regulator changine the pressure (im not totally sure you'll be able to pick that up).

You might check it cold, run it, then check it hot if you can't leave it connected while driving.
 

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Discussion Starter · #15 · (Edited)
Not dumb. The fuel system has a return. The pump supplies more fuel than is needed, and the excess is returned to the tank (two lines, one in, one out). The regulator is in the middle of the two lines, on the fuel rail (where the injectors are). The regulator is a "restriction" in the line, so that the pressure will remain constant on the supply side.

I think the regulator in you 9-3 will also be connected to vacuum source. This is to get a varied "restriction" to vary the fuel pressure. I've seen some of those regulators fail, and provide too great of restriction (too much fuel to engine causing a rich condition) or of course too litte. I've also seen the vacuum diapram in the pregulator fail and allow fuel to be sucked into the engine through the vacuum.

The gauge will connect to the fuel rail (there is a schrader valve or similar). If you verify a constant pressure, that is steady, your good. You should also rev the motor while the gauge is connected and see if you can see the regulator changine the pressure (im not totally sure you'll be able to pick that up).

You might check it cold, run it, then check it hot if you can't leave it connected while driving.
Ah simpler than I thought. Now to find said gauge! Also, I checked the hose to regulator, and no gas in it, so I doubt the diaphragm is broken in it. Or at least that's what I've been told is a sure fire way to know. Best part is, until about two weeks ago, that hose wasn't hooked up for a while and I was unaware. Apparently the car was able to figure out its fueling needs and it seemed to run fine.
 

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Discussion Starter · #18 ·
I got to looking at the cps, and the wire harness for it, and there is definitely a crack in the boot where the wire go into the sensor. Haven't got the proper torx socket to remove it, so have to go find one. Not that looking at it will do much, since I don't have a replacement to swap in, but hey its worth a peek I guess. Not hard to get to either.
 

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Discussion Starter · #20 ·
There is no schrader valve on a T5 as they take some funky saab tool/attachment to check prsssure which could be made. T7's have the schrader.
Ah those sneaky bastards! Yeah already asked Marks9-3, and he confirmed what I suspected on that. I pulled my CPS out to check it, and damn that thing looked crusty. Burned on oil goo, the thing looked evil. I cleaned it up as best I could, and put it back. The wiring looked ok, but like I said before, its cracking around the boot, so I kinda wonder if that is part of it. Going to look at my funds and order one tonight maybe.

What really sucks is that I'm moving about 30 min away, to a more rural area this coming week. Hoping I get this sorted by then, not to mention Ive been putting off working on my brother's Celica in the meantime, which pissed him off. That's what he gets for taking 4 months to decide what the hell he wants to do with it.
 
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