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Discussion Starter · #1 ·
Hi all,
My 1993 saab 900 turbo, runs great on he road to work, 2 lane hwy,
mostly 65 mph ride, just a few lights, but every time I try and use it
citywise, and have to stop for lights or go slow, the motor acts up,
bogs down, almost seems to go into limp mode, coughs and spits till ya get it back on a faster speed.
Any ideas?
This is the only mechanical prob that I haven't gotten fixed yet.
Any help appreciated,
Jim
 

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bad distributor cap rotoe or plugs, alright when running but clogging up as weak spark??, when idlling, or could be air hose(s) leaking check all
 

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if it were weak spark there would be bad missfiring when on boost.
that doesnt meant not to check the ignition system anyway though, i would be looking more into the fuel injection system, check it for codes to start with.
this should help with code retrieval: (if your C900 has a bosch system)
http://www.swedishwrench.com/flashcode.htm
 

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Discussion Starter · #4 ·
Well, went thru the drive thru window tonite and the car ran good the first 10 minutes, idled perfect at about 950rpm, when I put the car into gear to
move up , the car stalled out I had to push it to a spot, lift the hood, and
after about 5 mins of sitting like that it started, make a long story short, it ran like a dog after that, next turn I had to slow down, the car died again,
same drill lift the hood, let it go 5 minutes starts back up, will drive, but not
fast thats for sure, can't accellerate hard or it breaks up bad,
I am thinking about it tho, and haven't heard the fan running, do you think the fan would do that, I am ready to riip that insulation off the hood,
heat gauge is up there but nowhere near where I wold think too hot would be ....
Have already replaced plugs wires, coil, cap etc. this issue has been since first day I had the car more or less, new radiator, new water pump, new cold air intake, new fuel pump, filter etc .
 

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may be long shot but here goes. i had similar problem and it turned out to a bad contact at the mair mass meter. i cleaned and lubricated the contacts and never happened again. chris

also what part of texas r u in?
 

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I know/don't think there are crank case sensors onthe turbo's, but what you are having happening sounds exactly what I had on my 88 std 900 with CCS ok for about 3 mins or so ticking over till heat from engine got through to the sensor/or it just got hot and cut out for whatever reason, and then would misfire like hell and hardly driveable, so wether it's the wires that go into distthat are shorting if damaged etc or hall sensor etc,
 

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it's the wires that go into distthat are shorting if damaged etc or hall sensor etc,
This.

(i temporarily forgot about that plug/cable ;oops:)

anyway open the bonnet with the engine running, and wiggle the cable/plug on the side of the distributor. see if the engine note/running changes at all.
 

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Discussion Starter · #9 ·
I am going to check the fan first
I remember I had the bright idea when I put the radiator in to put two fans as I had one from my parts car and it fit..
figured would give it twice the cooling, but wired them both together.
When I first got the car that fan would run even after I got out of the car with it shut off, now I never hear it.
The car runs fine when you start it back up after one of these episodes, idles like a kitten till you put it in gear , the heat gauge is about 3/4 the way up from cold towards hot.
Odd how it starts with the hood open and not with it closed,
I had an issue one time on it with the coil wires, I am going to check those
again as well.
Bought dash lights todday so going to pull the dash and replace them and
redo the wiring on the heater switch I think I have that on wrong, but not a related issue
 

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the heat sensor on the rad is wired up to work after switching off, that's the idea, if you have bben siiting in a que for a while etc and then stop the rad and engine are very hot and will cool down but with the fan coming on and cooling it helps prevent over heating and heat pressure on everything involved that need cooling, having two just does it quicker no real prob there, but if things are happeneing when hood down It would suggest you have a trapped wire somewhere, or something is under pressure(touching) from the hood being closed
 

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Didn't see you mention this, although you probably have checked: make sure all the intake hoses are on tight. Even a seemingly small leak can sometimes make the car run like a drunken Irishman until it builds a little momentum. Might also be worth swapping in an Air Mass Meter from one of your other cars just to check that. They will do the same thing if they get really bad.
 

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Discussion Starter · #12 ·
well, as I have found out in the past , don't know why I forgot it this time, when something goes wrong with my saab, can spell it in 3 words, relay, relay , relay
The fan isn't working, probably why the car is doing this, not getting power to the fan even when the switch is jumped, of course fan runs when hooked up to 12 volts, so fan works fine..
fuses are good, there are 3 relays that power the fan, a\c a\c and fan relay,
My ac has never worked, the tubing was disconnected when I got the car ,
so I took the belt off.
I am getting voltage to the fan relay, but it isn't getting to the fan
I will try and swap out ac relays and see if that does it ..
I have the hoses all off to get to the wiring, so will clean the throtle body and also double check for air leaks on the turbo and clean the cold air filter again while I have it all off.
Thanks for all the suggestions, I may still be overlooking something,
 

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I can vote for the distributor - this afternoon my car started stumbling at 60km/h while trying to accelerate, I nursed it to where I was going and smelt coolant when I stopped, so opened the hood and heard a hissing sound. There was a pinprick hole in the top hose and spraying coolant over the distributor. I had problems restarting but managed to get back home and replaced the top hose and since then no problems with the acceleration.
 

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If the fan runs when you jump the fan thermoswitch in the rad, it's usually stuck 'open'. Check this link http://www.saabcentral.com/forums/showthread.php?t=182038 for a recent exhaustive analysis and discussion on similar problem re fan and disconnected a/c.

I agree with 16saabs re the possibility of a pinched vac hose or wire, but would expect that effect to be present more consistently when the hood/bonnet is closed.

Overheating might be causing vapour lock or some similar effect causing 'no start' until the hood is up for a while and things cool down sufficiently.
 

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possibity

i had a similar problem with a toyota celica and a mechanic of 20 years over heard the problem i explained. he replied the igintion control unit was the problem. replaced it and bam all was fime.

for the saab 900, eeuroparts number 3501921 is the amplifier.

if i were you, i'd find a donor car in a salvage yard, find the part, drivers side fender wall, and give it a shot. if you do be sure to put a fine layer of coupling compound or rear surrface of amplifier prior to mounting.

if you have problems finding one, let me know, i recently took parts from a 93 900 in lafayette la that still has one on it.

chris
 

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Discussion Starter · #17 ·
ok, have the car all torn apart, been working on it 2 days now,
I had to so a few things since I had the hood off, like clean up the lighting wires some, had some corrosion , so had to mend some wires, while doing this, looked at the wiring diagram in good old bentleys, and lo and behold, his diagram only shows one fan, when I looked at the wiring diagram is a green and black wire goes to the fan, I have a white and black one hooked up, jump the fan switch,
nothing, no voltage there but there is a click in the relay, tried to swap out with several same relays I have that size, nothing, click click , no voltage.
Then I decide am going to toggle the fan til I can trace further back, thru the ac
voltages, and realize that there is supposed to be 2 fans on the car, the fan from the radiator switch is on the pass side, still no voltage there ,
I wired the toggle in, as I already had a spare switch on my console, also have a red light for when the hood pops open and I dont realize it,lol,
I pulled the intercooler and hoses, going to clean all under that as it gets debri in there sometimes, gonna vac that all out and put it back together , as I have to pull the dash and replace instrument bulbs while I have this apart and realign steering wheel so I can see the gauges when I am driving , and also check the horn again, last time it shorted and I also think I have the wires wrong on the ac switch, which may be the problem with the fan.
as it gets voltage from ac relay also.
I know this worked when I bought the car, and when I replaced the rad. I replaced the thermo switch as well.
At this point , I am gonna ask a dumb question, It seems to me when I first got this car, and pulled the intercooler out, it had coolant in it,
I have never put any coolant in the intercooler, does it require coolant ???
Thanks ahead, should be done with this whole project and be back on the road tomorrow, headlights aligned, turn signals all cleaned up, cold air filter cleaned , and a toggled fan for the moment, I have wired up test leads from the fan hook ups so that I can check them once I get ac correct
 

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if its a standard intercooler then there should not be coolant in it. if its a charge cooler (water to air) then there should be connections on it which go to the cooling system. if the coolant you speak of is in the intake pipes then i would be looking at the PCV pipe coming from the valve cover to the inlet side of the turbo, as it also has galleries for coolant to pass through it IIRC, there should be 2 small hoses connected to it, one goes to the throttle body and the other goes to a metal pipe under the inlet manifold.

i have only seen this setup on some turbo C900's, so i could be wrong. if i am, someone please correct me.
 

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Discussion Starter · #20 ·
I still have the same issue
drove the car today, 91 out ,the car runs like a top, I can stop for a light, car purrs and if the light is red under a minute, no problem whatsoever.
I have the fan on a toggle, toggle it on at the light, now, the heat gauge is barely halfway up and yes have checked gauge works fine.
Texas where I am the lights are long and frequent, all 4 way lights, between 3 and 5 minutes a light and where I went today, are 2 blocks apart.
I made it thru 3 lights before the car started acting up, breaking up when taking off.
I pulled the car over,. let it sit a while, fan on, hood up, started it back up, made it up the road to the first light and it dies out.
I pulled the car off the road, let it rest again, fan on again, and I am starting to suspect this issue has nothing to do with heat,oxygen sensor maybe, or, what I really think issue may be is fuel filter screen in fuel pump and fuel filter as well.
low rpm for awhile and the car isn't drawing much gas, when ya hit the gas, it may be sucking dirt to the screen and starving it for fuel causing the bad
running condition.
Any opinions, have tested all that is on this page, and nothing has fixed it, hall sensor fine, coil wires not pinched, all vacuum wires tight, can drive this car 40 miles without even a sputter, great turbo, lots of power as long as I am going at least 45-75 mph. stop for a light bang, big problem.
Also have a hole in the muffler , probably totally unrelated, but at this point...
will grasp at straws..
Thanks for any help
Jim
 
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