1998 Saab 93..... Talk to me

[Little eddie]

So as the title says ive got one of these in 2.0 litre turbo convertible form. Ive a couple of issues with it so here goes.

Firstly the fuel economy is catastrophic!! I'm getting 15mpg according to the display. So far ive changed the oil, air and plugs, checked tyre pressures and had it on the emissions reader at the garage next door to work (with near pefect results). What else should i be looking at?
I don't really want to be spending 50 quid on lambda sensors if there is no need.

Secondly it has an awful wobble on the steering wheel but only occasionally and only from it appears when its cold? Its also apparant when i hit bumps etc. Ive just had it mot'd no probs and theres no noises i can hear and also the steering rack doesnt appear to be loose like i know these suffer from. My only thought is that ive just had 2 new tyres put on but these were a budget range!!

So talk to me, tell me what you think......

[austinpowers]

If the two new tyres are on the front,try swapping with the back set. I have had cars with budget tyres, and it can have quite an effect on the way the car handles. Especially if it's something with a bit of weight like a Saab.

[volospian]

As for economy. .. not sure. I'd have thought that if idle was using closed loop and the lambda was iffy, then the idle would be iffy too. I suppose it may not have been closed, maybe too cold, but I'd have thought that issues with the lambda, or pretty much any other major sensor, would have shown itself on a gas analyser as the ECU wrongly adjusted the mix according to the wrong info.

Is not something as simple as a fuel leak, is it?

Again, wobble could be a few things. Worn bushes in a number of locations springs to mind, but, as a simple case of stating the bleeding obvious... you don't park it on a gravel drive, by any chance? My Jag has awful wobble while cold because it hasn't thrown all the gravel out of the tread until after the first few miles. Just a thought

[Little eddie]

Gravel drive? Definitely not, its parked on a rough council estate in Birmingham!! The wobble just seems to go away after a few miles driving so i can see your logic.

As for the fuel issue theres no leaks and I'm getting around the same mileage on every fill up - which is very often!!!

[EssexRich]

blocked cat? That can really mess with Saabs fuel economy. Also, does your engine light come on often?

Have you changed the DI pack yet, especially if your engine light comes on a lot.

I think the B204 uses a maf sensor instead of a map sensor like the b205. I could have that back to front, my memory's not great! Either way, that could be messing your fuel economy up.

Failing that, new plugs, oil and air filter might be worth a shot.

Realistically, get a friendly saab specialist to plug in their Tech II machine to give you some detail...

[volospian]

Hmmm... if the idle is showing correct, my guess would be the issue is over-enrichment on acceleration. I wonder if the MAP sensor is iffy, showing greater pressure under boost than is actually there, causing overfuelling. That would be in open loop so the lambda wouldn't adjust the mix?

Unless, of course, the idle isn't closed loop but a static map and the lambda is indeed buggered

As for steering wobble... something slack which warms and expands (and thus tightens, reducing slack) with friction? Bearings? Ball joints, perhaps?

[ChasR]

Nov 4, 2015 21:38:43 GMT Little eddie said:

So as the title says ive got one of these in 2.0 litre turbo convertible form. Ive a couple of issues with it so here goes.

Firstly the fuel economy is catastrophic!! I'm getting 15mpg according to the display. So far ive changed the oil, air and plugs, checked tyre pressures and had it on the emissions reader at the garage next door to work (with near pefect results). What else should i be looking at?
I don't really want to be spending 50 quid on lambda sensors if there is no need.

Secondly it has an awful wobble on the steering wheel but only occasionally and only from it appears when its cold? Its also apparant when i hit bumps etc. Ive just had it mot'd no probs and theres no noises i can hear and also the steering rack doesnt appear to be loose like i know these suffer from. My only thought is that ive just had 2 new tyres put on but these were a budget range!!

So talk to me, tell me what you think......

Right, I'll go through a few things.

What kind of driving do you do? Is it all town work or do you go elsewhere? That will have a big impact on MPG. For me, going to work in the Clio where the engine barely warms up in time will see me getting 28MPG and that is with the car generally not coming to a complete halt all that often. On a run I've seen 42MPG and I was not being careful for the entire lot. For most of that trip I was doing 75-80MPH and on occasions I was toying with other drivers too . That's the difference a journey can have on fuel MPG. Have you checked for any codes from an OBD reader or does the car pre date this?

Secondly, what I saw happen with my dad's W reg 2.0 HOT in 2003 will open a can of worms. He also used to suffer with horrific tyre wear and wobble. A Kwick curse word garage said to the lady in the reception that only Michelins should be fitted otherwise he (my dad) would keep coming back with balancing issues. Due to the costs of a company car allowance Dunlops were fitted. The mechanic was not wrong. On the Michelins the car was far better behaved and the tyres lasted longer, but still not amazing by some car standards.

That said, I would check the wheels for a buckle, the tyres to see that they have not deformed in addition to seeing whether your bulkhead is in good condition. I'd probably also consider getting the Abbot Racing torque steer fix if the bulkhead is in good condition. The latter 'might' help matters. I'd have said a TRE was shot but you said the car is fine. Are the driveshafts in good condition?

[volospian]

Just for comparison, I used Avon ZZ3's on my '99 2.0 HOT. Never had the Abbott kit and never really suffered any untoward wear or wobble. I used to get mid to late 20's MPG and never hung around. Having said that, my 3.0 v6 X-Type auto used to return around 18mpg. Is the offending vehicle auto or manual?

[gadgetgricey]

My old 900 V6 Convertible (auto) used to average 18 mpg round town but over 35 on a run.

Have you done a tank to tank calculation. Could be that you are getting a higher figure and the SID display is wrong.
Talking of the SID display are the pixels all there.
Just wondered if you might be reading 15mph as average speed instead of 15 mpg??

A slightly devious option may be to get the Car remapped via Karl at Noob tune. You;d end up with a faster car, and hopefully he would sort out the fuelling issue for you at the same time.


Have a concern re the wobble, as these are prone to the bulk head cracking, don't know if it matches your symptoms, but its something you might need to investigate.

If you are not already a member of UK Saabs, it might be an idea to join as there is a lot of knowledge on there regarding Saabs.

Hope you get it sorted,

Cheers

Dave

[Little eddie]

Ok just an update on things.

Its an automatic with a b204e with the red cassette (already been changed) and runs very smoothly. There are no management lights on the dash and the sid display works perfectly (yes i know!!). I havent really looked at the maf sensor being an issue as no eml light on.??

Just to put into perspective, i put 30 quids worth of fuel in and return around 100 miles. This is driving round town with minimal stop start traffic.

As for karl at noob tune.... Where is he based? I wouldnt mind having it remapped/looked at to be honest.

[gadgetgricey]

Nov 5, 2015 22:14:50 GMT Little eddie said:

As for karl at noob tune.... Where is he based? I wouldnt mind having it remapped/looked at to be honest.

Website and contact details as below

www.noobtune.co.uk/

I think he's based Northampton way, but drop him an e-mail. He's highly regarded on UKSaabs

Cheers

Dave

[adam73bgt]

Karl did a great job on my Aero HOT and helped me sort a couple of little issues the car had when I brought it to him Hes not far up the M1

To check the bulkhead, get someone to steer from lock to lock while the car is stationary. Meanwhile watch the bulkhead around the drivers side area sort of around the brake servo, thats where mine had started to crack.

That mpg sounds a bit on the low side to be purely as a result of city driving to me? My car never gets near going below 20 even with a heavy right foot. (Albeit mine is a manual and the B205 engine which is supposed to be a bit more economical)

Did the plugs tell you anything when you changed them? Any chance the car is running very rich?

[keithyboy]

I don't think Karl does T5 (red cassette) ECUs. Jules_HT on UKSaabs does though (for stupidly small amounts of money). He's down in Somerset or somewhere like that but will send you an ECU on an exchange basis.

However, the only way I can see a remap fixing it is if it's already been remapped by an incompetent. Daft as that may seem, the software is a lot more widely available than the ability to use it properly.

Mine spends a lot of time in traffic but still doesn't dip much below 25mpg.

[adam73bgt]

Nov 6, 2015 12:50:19 GMT keithyboy said:

I don't think Karl does T5 (red cassette) ECUs. Jules_HT on UKSaabs does though (for stupidly small amounts of money).

Ah yes you're right, forgot the OP's car is T5

[Killbill]

Get yourself over to www.uksaabs.co.uk/UKS/index.php
Great bunch of saab nutters if they cant help i don't know who can.
Have you checked ALL the vac lines for cracks and splits a small vac leak can cause all sort of fuel metering problems,the small ones around the bulkhead are known for poping off or spliting.

[paulmakin]

reset SID and see what happens - the unit is reliable, unfortunately the inputs it uses for displaying the data aren't always ! can't remember if this tank has an upper baffle - if it has, this as a notorious source of improbable fuel shenanigans (but i think this is just the 9-5's)

is the boost behaving normally? a collapsed cat will impair mpg and shows up as low boost etc.

temp coolant sensor worth considering - there are 2, one talks to the ECU and the other informs the gauge. an open SID (Jules can fix this for you) would let you see what coolant temp the ECU is actually seeing. faulty data could give rise to overfuelling as the ECU stays in coldstart cycle.

could be a lambda staying in closed loop and holding control of the fuelling. in open loop the maps take over with no compensation from the lambda. the "wrong" lambda will screw the fuelling as the voltage expected by the ECU will be outside the parameters it's looking for. i can't recall my T5's but on T7 the upstream sensor does the hard work with fuel trimming so test him first. Trionic is very particular about what sensors it communicates properly with and Lambda faults don't always give you the EML so T5 self-test no good here I'm afraid

i have seen a MAF incorrectly fitted which gave some very chin-stroking figures on SID

every saab i've ever had has been very sensitive to tyre choice - distinct shimmy with some brands and not with others. are your budgets "high load"? - they should be. budgets do work OK on Sabbs though, on the 9-5 i currently have a set of BCT (just liked the tread pattern !!) and they've been great. the 9-3 is pants on avons but fine on conti's - go figure !! check lower arms again - these can often pass an inspection whilst signalling their gradual deterioration at the same time. i used to buy the premium brands but found that it's more cost effective to use the cheapest i can find and treat as a service item.

you can easily check for bulkhead cracking yourself (it's not actually a crack - it's a weld that unpicks itself) by sitting in it and swinging the wheel around. movement of the pedals would be the worry.

strut top mounts worth a look, especially as wobbling is more pronounced on bumps. all cheap and easy fixes, rack and subframe braces will help enormously on a 'vert (which, frankly, are renowned for being wobblier than a champion wobbly thing from wobble town)

thinking tangentially - wheel wobble and poor gas mileage? are the brakes OK?

start cheap though - check plugs (make sure you have the correct spec, it's for a reason), air filter etc.

paul

[Little eddie]

It goes on

Came home tonight and the mpg has plumetted to 14mpg and the car has now developed an idle speed of 2500rpm.

Its so dark i could cry

[paulmakin]

air leak on the inlet side?

lift the plastic cover over the TB and see if there's anything obviously amiss with cabling etc.

idle control valve gummed up ?

again, possibly coolant temp sensor playing up ?

TB's are known to have issues relating to the readings received by the ECU being outside the tables - the electronics get manky after a few years and the readings become variable. It's an easy replacement but would have expected a CEL and a "performance related problem" to be showing up if the TB had discrete problems.

paul

[froggy]

T5 management so first thing is go through the vac lines as its a speed density system so vac leaks through perished hoses will cause lots of issues . PCv valve needs to be checked as well . Clean the Iscv and replace any crumbly vac lines . Disconnect battery for a few minutes and restart letting the ecu sort the idle control out . If you've got a very high idle and cruise fitted make sure the cruise cable isn't pulling the throttle open

[volospian]

Nov 6, 2015 21:35:16 GMT paulmakin said:

the 9-3 is pants on avons but fine on conti's - go figure !!

paul

Suprised at this statement. I got through 4 sets of different tyres when I had mine and the Avons were the only ones that made the car feel properly driveable. Worst were Eagle F1's. Godawful. No grip and only lasted about 6 months.