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Discussion Starter #1
My '89 9000T AT 120k has started hesitating, by which in this case I mean that I've had several instances now where at low speed, say 25mph, I want to speed up but applying the pedal doesn't increase the revs at all. In fact the revs I still have aren't powering the car forward. So for a few seconds I'm just rolling as if in neutral, then something 'catches' and the motor revs up. It feels like the car is about to stall completely, but it doesn't quite do that.

After the first couple of instances I did some web research and found one thing I could do myself right away. The idea was to get off premium gas (I usually run 92 octane). I had room for only about 6 gallons, so I added that in 89 octane. It happened again anyway. A car savvy (but not SAAB-savvy) friend suggested that since it was so intermittent it probably wasn't a vacuum leak or other constant, but an electrical short. I then took it to a knowledgeable SAAB mechanic (Ryan's in Northampton, MA) and of course they couldn't get the symptom to appear on a test drive. Nevertheless they found a failed turbo bypass (hooter) valve, replaced it, and cleaned the throttle plate.

For a few days after that, maybe just 75 miles, it didn't happen. Then last Sunday it happened as I was exiting a turnpike tollbooth (after running at 85mph for an hour). Since then it happens every time I take the car out, within as little as 100 yards, up to as far as 2 miles. So it's not a running hot symptom. These last few instances have been not quite as alarming as the first three, lasting maybe 3 seconds instead of the previous 6 seconds. I now have another appointment at Ryan's on Monday.

Meanwhile, any guru ideas?
 

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My '89T had a hesitation that I tracked down to a fuel pump problem. If your's happens when your gas tank is below half full, suspect the pre-pump. Otherwise I'd suggest the main pump. Mine was the pre-pump and has been fine ever since replacing it.

YMMV,
Rod.
 

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Discussion Starter #3 (Edited)
Just stalled completely, and thanks Rod

Yup, right in the middle of an intersection (of course) just after the light turned green for me and I did a normal moderate forward movement. On the 3rd try she cranked over and I was able to hobble 2 miles home.

Thanks for the pre-pump idea. After reading that I put in $20 premium (about 3/4 full then) and it seemed good for a few miles until the stall.
 

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Discussion Starter #4
It was the pre-pump, and/but...

It was the pre-pump, and/but...

Anyway, Ryan's identified the problem as the pre-pump. But they said they couldn't get a new one, the Saab dealer only sold both pumps as a single buy, for $1000. So they wanted to adapt a non-Bosch main pump to function as a pre-pump, part cost $350. Meanwhile I'd found a Bosch pre-pump at saabsite.com for $46 shipped. They also told me it'd be an easy install for a non-mechanic IF I didn't break the connectors. So, wanting a backup, I asked Ryan's if they'd install it. No, no customer supplied parts. So I called a different mechanic who said he would, made an appointment, and ordered the pre-pump.

I went back to Ryan's just now to pick up the car, hoping I wouldn't need to be towed someplace. Good news, though. They bypassed the funky pre-pump so gas is directly sucked in by the main pump. They told me to definitely now keep the tank above half full, because the main pump can only get gas from the top half. Drove home totally problem-free, after paying $130, all labor.

:confused: This is making me rethink my pre-pump order and appointment to install it.
 

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If I remember correctly, the purpose of the prepump is to fill a smaller reservoir with gas from the main tank that the main pump then draws from. This is to maintain a constant fuel supply level and avoid fuel starvation when the tank is low and its sloshing around and maybe not keeping the pickup supplied 100%. Sounds like a performance thing, and you can probably get away without it. But then, you could probably get away without the turbo... ;-)

I'd spend the $46 and DIY.

YMMV,
Rod.
 

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Discussion Starter #6 (Edited)
Saabsite tech says it prevents main pump overheating

Yes, Ron, all you said is true, but also yesterday a Saabsite tech told me it prevents main pump overheating. Whether he meant because the main pump would be dry-pumping out of an empty top half tank =8^b - or just because the turbo demand for fuel overtaxes the main, I don't know.

SAAB designers have always marched to a different drum, eh? Who else has a pre-pump?

p.s. I will have the pre-pump installed.
 

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Discussion Starter #7
Even with new pre-pump, STALLED AGAIN

The new pre-pump went in this week. The car felt fine for the first 40 or so miles, routine stop and go, 15 miles of 65mph. Then today, 10 miles at 80, exit freeway, one red light, second red light, third red light (all within 300 yards), STALLED trying to move on green light. Turned over and ran OK after 3rd crank. :( AAAAAAAAAAAAAArrrrrrrrrrrrrrrrrrrr!!!!!!!!!

So what else could it be?
 

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I once had a similar problem. It sounds like the fuel system is not fully pressureizing, or is losing pressure. Check all the fuel lines, fuel filter, gas cap, etc. Somewhere you have an air leak. Check the lines/hoses at the main pump carefully as this is the prime suspect area. Flexible or rubber hoses first!
 

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Discussion Starter #9
midway said:
I once had a similar problem. It sounds like the fuel system is not fully pressureizing, or is losing pressure. Check all the fuel lines, fuel filter, gas cap, etc. Somewhere you have an air leak. Check the lines/hoses at the main pump carefully as this is the prime suspect area. Flexible or rubber hoses first!
Thanks, I'll check what I can, then have a pro check.
 

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Discussion Starter #10
fuel pressure vs air pressure

midway said:
fuel system is not fully pressureizing, or is losing pressure. Check all the fuel lines, fuel filter, gas cap, etc. Somewhere you have an air leak
OK, I did say I'd do what I could first, but that turns out to be nothing. I'm semi-disabled and cannot get down in there to the pump. Then, I was going to take it to the foreign-cars-only place which installed the pre-pump, which prides itself on solving tricky problems. Nope, on vacation. So then, I figure if it's as simple as an air leak my local gas station mechanics can find and fix that. So, over to them.

They said if I had a fuel line leak the car wouldn't even run. Then, they'd want to test drive it to diagnose it. And if it didn't happen they couldn't fix it. I think they're just putting me off there. So far the car has always started up with a few cranks after a stall. What would they do, wait for a stall, not start it, get out and try to diagnose it right there in traffic? And I don't see the car not running at all if there were a leak.

But that got me thinking (something I'm not qualified to do when it comes to cars)... if there was a leaky line, wouldn't the pump(s) pressure push the gas out the hole under throttle? And even at idle why would air pressure be greater than gas pressure, allowing air infiltration? I'm missing something here.
 

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Discussion Starter #11
dead, towed away

Well, before I could get anyone to take it in and check the fuel lines, it died in the driveway yesterday. It would start OK (again and again) but I noticed the idle wanted to go way low, c.400rpm, and when I put it in reverse it'd go about a foot and die as the idle went to zero. It definitely felt like no gas was getting through. I checked my plug wires and a couple were a little loose, but jamming them tight didn't help. So I had to get towed.

Possibly connected: the day before I'd put a container of STP Fuel System Cleaner in a full tank of premium, then drove home just half a mile. No more driving until the above incident. It occurs to me that this STP might have dislodged some sort of sludge somewhere in the line, which then made its way to the fuel filter. Hmmm, dunno.

Further, I had to get it towed to my local gas station, decent mechanics, low rates, but not particularly Saab-savvy. My Saab specialists were a. on vacation for another 10 days, and b. working but full for a week. So, the Citgo guys are having a look today and will call me. Or not. I did tell them the fuel pressurizing theory as well as about the STP. We'll see.
 

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Discussion Starter #12
nothing done, no charge, drove home

OK, at the end of yesterday they told me it had started and run just fine the day before, but it had stalled yesterday, and I needed a new fuel pump, you have to do them both at once, but that it's running fine now, come get it.

So I did. Turns out the above was all second hand, the mechanic who dealt with the car had gone home. I asked the other one if he knew whether the new pump was a guess, whether any other cause had been eliminated. Didn't know, call Monday.

Drove home fine. Strangely intermittent, the sort of thing I'd guess was electronic rather than mechanical.
 

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I don't think it a fuel thing

You can get symptoms like you describe from a bad dist. rotor. Its a cheap fix you can do yourself. Change the cap and rotor. If the problem persist try a new coil.
 

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Discussion Starter #14 (Edited)
dcm24 said:
You can get symptoms like you describe from a bad dist. rotor. Its a cheap fix you can do yourself. Change the cap and rotor. If the problem persist try a new coil.
Thanks, dcm24. I've been thinking along those lines myself, and called a buddy Sunday to see if he can help me with the distributor, coil, plug wires, etc. I've been skittish about working with cars' engine electrics and gas ever since I burned a car to the ground once when the gas hit a live wire. Anyway, in a few days. Then yesterday I spoke with the mechanic who'd prescribed a new fuel pump. No, he didn't test *anything*. All he did was call a foreign car garage who told him that you always have to do the two pumps together. No wonder there was no charge to have the car there for 40 hours!

Reviewing, the mech who tested the pumps and found a bad pre-pump never said that, nor did the mech who actually installed said pre-pump. Both have been hands-on Saab guys for 25 years.

Meanwhile, both Sunday and Monday starts and stop'n'gos have been stall free.
 

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Also check the AT cable, my girlfriends 9000 was going the same a couple years ago. Just be driving and then out of the blue, revs and it wouldnt go, just like if you had popped it in neutral. The cable was getting fouled up on the way from the throttle to the at.

-Alex
 

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Discussion Starter #16
7 days no stall, clue(?) remembered

Yesterday marked the end of 7 days of light driving with no stalling or hesitation. Yet, in review, it did both after a new turbo bypass valve, after a new pre-pump, and after adding STP. Nothing's been done to the car in those seven days.

So, I've been trying to unearth any clue I can to what might have improved the situation. I remember now when I was waiting for the tow truck when it last stalled (see "dead, towed away" post above), I opened the hood and examined the battery terminals (fine) and plug wires and coil wire at the distributor and coil. Two were loose at the distributor, to the point that I could feel slight movement when I pushed them in. I wish I could remember now which two that was, because one of them not only pushed in but produced a small, quick BUZZ I could feel and hear. The key was off. Maybe it was the coil wire. I wish I could remember if I had time to try the car again before the tow truck driver came. For some reason he preferred to tow the car with it running. He started it, and it ran all the way (a mile) to the Citgo garage without stalling!

Now, the Citgo guys later told me that it wouldn't stall for them that day but that it did stall the next day. I wouldn't put it past them, though, to make all that up just to reassure me they were on the case.

In sum, it hasn't stalled for me since the loose wires, nor for the tow guy, and maybe not for the garage guys - for seven days.
 

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Discussion Starter #17
probably the distributor

Well, yesterday after seven stall-free days the car stalled again on the first start of the day. Then again. Then I revved it a bit and tried again, with a stall. Then, ditto. Then, I revved it for a whole minute at about 3000 rpm, let the rpm drop to around 1000, engaged reverse, and was able to get out of the driveway and drive to my buddy's house to install a new distributor cap, rotor, O-ring and plugs.

Taking off the cap, we discovered a couple of things.

First, there was oil inside the cap (not on the contacts) and a tiny bit on the rotor. The O-ring I brought seemed a different size from the one on the outside of the distributor shaft, and (if I understood him right) he didn't think it could be a preventive for that oil. He thought it must be an O-ring to replace a different one inside the shaft, and he couldn't get the shaft apart with the tools on hand. So the O-ring didn't get replaced. Is there more than one O-ring?

Second, the plastic mounting wings of the "distributor pickup", the wiring gizmo attached to the side of the distributor, were broken. The part of the wings that fit inside the outer distributor wall to hold it on had broken off some time in the past, and someone had just glued the outside wings part to the outside of the distributor wall. The glue had (recently?) broken so that the distributor pickup was floating around free. Also, trying to disconnect the distributor pickup, he found that one of the wires broke, and broke so easily that its integrity/functionality was suspect.

He thinks my intermittent stalling problem was most probably caused by this distributor situation, both the oil and the distributor pickup free-floating and the suspect connection. Of course late on a Saturday any decent price for a distributor or distributor kit was out the window. Fortunately he makes his living doing military grade soldering etc and has his own bench at home. He soldered some new distributor pickup wiring, all of it, to probably better/stronger than new, and longer, so that the distributor pickup is now truly floating free of the distributor, with just the perfect amount of slack that it doesn't get sucked in and jam the distributor. The car drove home fine.

So, early this week I'll be looking into buying a new distributor or rebuild kit. I'm looking for any helpful comments on this, and since this is such a long thread now, I'm going to start a new one.
 

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IMO it sounds like your Air flow meter is going out. This happened to my Toyota recently and the symptoms were pretty much identical. If you know anyone else with a 9k swap AFMs with them and see if it fixes the problem.:)
 

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I am still betting on the fuel system losing pressure. If the rotor/cap doesn't fix it take it to your Saab guy and have him check the fuel system for pressure. Mine was doing EXACTLY what your car is doing and it turned out to be a cheap rubber hose in the tank.
 

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Discussion Starter #20
update - NOT fuel, distributor or AT cable - AMM?

I got the car towed to a fine foreign car shop (not Saab specialists, though) on Monday 8/15. It was Wednesday then before I had any news:

Wednesday: Shop says they haven't seen any stalling issues, and fuel pressure tested fine. 2 people took it for a drive, but they both mentioned that the transmission "seemed to be bucking", and I should drive it with one of them when I pick it up. I've never noticed any tranny problems with it. I mentioned the "fouled AT cable" idea but shop says it's fine. OK, anyway, the idea is that they're finished with it (BAH!), the new plugs and wires are in, and I can come get it. $65 charge for fuel pressure test, inspection of distributor, and gap and install my supplied new plugs and ignition wires (NGK, Bougicord).

Thursday: Got there and took it for a ride to check transmission, but that never arose as the car started hesitating, the 'check engine' light came on (never before), and after a few hundred yards we had to hobble back to the garage going about 5 miles an hour. Flooring the gas did nothing. The car would idle, but roughly. The mechanic then disconnected the Air Mass Meter to try to get the car computer to reset. No help. I asked if that meant the AMM was NOT bad. He said no, it just might be the AMM. The used AMM still hasn't got here from the eBay seller! Shop said I should leave the car there, at least now they've seen it stalling and might get some code out of it from the check engine. I asked him then about the distributor. They did look inside, no oil, the wiring job looks fine, and distributor problems wouldn't result in these symptoms anyway, don't bother buying a new or used one. They didn't remember to do the O-ring, though. I left the car there. Hopefully the AMM will come in the mail RSN (Real Soon Now).
 
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