| Author |  Topic  |
andydeans3
V4 Guru
United Kingdom
2012 Posts |  Posted - 26 Mar 2019 : 08:05:55  
| I've got a small issue I thought someone could help with.
In the morning, if the car has been run the day before, one pump of the throttle, turn the key, she starts fine.
If, however, she's been left in the garage for a few days, (with the battery disconnected), she becomes a real bitch to start.
Starting hot, no problem.
I have so far checked and changed the following:-
- New plugs, with gap set correctly.
- New dizzie cap
- new rotor arm
I have checked the timing, (8 degrees), the compression, (140 to 150 psi on all cylinders), and have also checked that the choke flaps are closing.
When she won't go, if I spray some "cold start" spray on the air intake, off she goes, no problem.
Spark seems good, and the battery is not old. It's a Halfords battery with one of those indicators that tells you the state of charge.
It has at times in the past helped to jump another battery in parallel. (before I bought the "cold start" spray.
Any ideas? The carb perhaps?. It's a twin choke Weber, about 3 years old.
She's running a bit weak I think, plugs are almost white. I'm wondering if this is part of the problem.........mixture needs to be rich for cold starting.
Am I correct in saying that you screw the idle jet screw out to richen the mixture?
Any input much appreciated.
Andy
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro |
Edited by - andydeans3 on 26 Mar 2019 08:10:16 |
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deggsie
V4 Fanatic
United Kingdom
432 Posts | Posted - 26 Mar 2019 : 08:50:04
| Andy
I have similar issues, though in my case it's after leaving the car for several weeks !
I believe it is largely as a result of fuel taking a while to pump up to the carb - I keep meaning to try a non-return valve in the fuel line.
The fact that it works OK after a squirt of 'cold start' seems to confirm it's fuel related ?
On the carb adjustment, it is indeed 'out to richen' - I imagine you have two idle mixture screws on a twin choke.
___________________________
Saab - beyond the conventional ! |  |
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melle
V4 Guru
United Kingdom
3833 Posts | Posted - 26 Mar 2019 : 09:07:27
| Andy, if it's running lean, start by checking for air leaks at the base of the carb and the vacuum hose. Also doesn't harm to re-torque the intake manifold, which is a common source of vacuum leaks. Why have you set the timing at 8 degrees instead of the 6 prescribed? Get yourself a Haynes Weber book, it will help you get a good understanding of your carb.
quote:
Originally posted by deggsie
I believe it is largely as a result of fuel taking a while to pump up to the carb - I keep meaning to try a non-return valve in the fuel line.
Even after a few weeks there should be enough fuel left in the bowl to get it to start. I doubt a non-return valve will help, as there is one in the pump already.
quote:
Originally posted by deggsie
The fact that it works OK after a squirt of 'cold start' seems to confirm it's fuel related ?
This is a misconception I think. Because "cold start" (or brake cleaner, which does the same and is much cheaper) has a much lower flame point, it will also improve starting in case of, say, a weak spark.
quote:
Originally posted by deggsie
On the carb adjustment, it is indeed 'out to richen' - I imagine you have two idle mixture screws on a twin choke.
No, just one.
www.saabv4.com |
Edited by - melle on 27 Mar 2019 19:32:24 | |
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Dirtbiker
V4 Guru
United Kingdom
1061 Posts | Posted - 26 Mar 2019 : 20:20:12
| I have the same issue with the 96 and I don't think a non return valve will help as surely there will be fuel in the bowl...?
Mine "feels" like it is cranking then fuel comes through and it then starts.
However, I think Melle could be onto something in that if I have a weak spark then the fact the the engine is physically harder to turn over when cold may delay starting. I am planning a thorough overhaul of the ignition system so it will be interesting to see if this cures the problem. Don't hold your breath for an answer though - campervan out of the barn next week and sunshine nearly persuaded me to drag a motorbike of hibernation on Sunday! | |
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andydeans3
V4 Guru
United Kingdom
2012 Posts | Posted - 26 Mar 2019 : 21:40:17
| Thanks for your input guys.
Melle - I didn't set the timing at 8 degrees, I simply checked it, and being at 8 degree, it seemed reasonable.
Air leaks at the manifold are something I could certainly check, though I do habitually check the tightness of the carb nuts.
Deggsie:- I have two check valves in the fuel lines. One just below the carb, and one under the back seat. The one under the back seat was added at the behest of Steve Broadhaead, to fix an earlier, unrelated problem!
There's only one idle jet adjusting screw.
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro | |
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GeoffC
V4 Mad
United Kingdom
507 Posts | Posted - 26 Mar 2019 : 21:45:03
| | Had a similar issue with my Sonett (28/36 carb) but not quite as bad. Fitted the Acuspark ignition and new coil since then it's started instantly! | |
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melle
V4 Guru
United Kingdom
3833 Posts | Posted - 26 Mar 2019 : 22:27:29
| quote:
Originally posted by andydeans3
Melle - I didn't set the timing at 8 degrees, I simply checked it, and being at 8 degree, it seemed reasonable.
You say the engine is running lean, so in theory advancing the ignition timing a few degrees would help for slightly cooler running. I'd rather fix the underlying issue though, no reason to deviate from six degrees with a standard engine I think.
quote:
Originally posted by andydeans3
Air leaks at the manifold are something I could certainly check, though I do habitually check the tightness of the carb nuts.
I meant re-torquing the manifold bolts and nuts, I've often found they were loose.
A bit confusing you cross-posted this on UKSaabs, have to read my previous posts to see what I suggested where!
www.saabv4.com | |
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melle
V4 Guru
United Kingdom
3833 Posts | Posted - 26 Mar 2019 : 22:36:55
| Oh and don't over-tighten the carb nuts, it will only bend the base and cause air leaks.
www.saabv4.com | |
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andydeans3
V4 Guru
United Kingdom
2012 Posts | Posted - 27 Mar 2019 : 15:36:20
| Melle
Yeah, perhaps wasn't a good idea to cross post on UKSAABS as well, but it's good to do that to get maximum coverage.
Andy
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro | |
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pchristy
V4 Guru
United Kingdom
1790 Posts | Posted - 28 Mar 2019 : 18:23:00
| Every V4 I've owned takes a while to start after its been left a few days. The fuel drains back down the line, and there isn't sufficient left in the bowl for a cold start. You just need to keep cranking until the fuel gets through to the carb again!
The non-return valve didn't work for me. The only cure is to fit an electric fuel pump, but that can have its own complications! I fitted a Huco suction pump in the engine compartment, but it would vapour-lock on hot days. If you fit one in the back, near the tank, its a good idea to fit an inertia cut-out in case of accidents.
Or do as I do, and use the car more often! ;-)
--
Pete
"Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!" | |
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melle
V4 Guru
United Kingdom
3833 Posts | Posted - 28 Mar 2019 : 18:28:59
| Andy's 96 must be one of the most frequently used ones in the UK!
www.saabv4.com | |
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andydeans3
V4 Guru
United Kingdom
2012 Posts | Posted - 28 Mar 2019 : 20:49:10
| Melle
Aye, I bought the car in August 13 from Ron, in Kent. She'd been displayed at Wicksteed Park, at the English SAAB International.
At that time the odometer read 29 000 kms, which was in fact, of course , 129 000 kms, She's turned the clock again and is currently reading 20 000 kms, so in 9000 kms, I'll have done 100 000 kms, or 62 000 miles,in 6 years, so around 10 000 miles per annum.
For me a car is there to be used, not be taken on a trailer, to car shows. I drive her to car shows. Next one will be Swedish Day in May.
She's not perfect. She has quite a few "warts" in spite of a re-spray in 2016, but I love her.
I don't own a modern car, my "other" car is a 1978 MGB, which I've owned for more than half my life, but I hope to sell soon. (As soon as I get the historic status for it, next week).
I'm just glad that, given my age, I'll hopefully see out Internal Combustion driven cars, before the electric car revolution consigns them all to the scrapyard, due to the unavailability of petrol!!!!!
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro |
Edited by - andydeans3 on 28 Mar 2019 20:50:41 | |
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pchristy
V4 Guru
United Kingdom
1790 Posts | Posted - 28 Mar 2019 : 22:44:20
| I wouldn't worry about the unavailability of petrol, Andy! I suspect that as electric takes over, petrol prices will drop due to the lack of customers for it!
My other hobby us building RC model aircraft. For years we used 35 MHz as a control frequency. Then the "Spread Spectrum" revolution occurred and everyone move to 2.4 GHz. Well, I say everyone - the canny ones stayed on 35 MHz, which is now almost deserted, but for which you can pick up equipment that would have cost hundreds of pounds for peanuts!
For every cloud there is a silver lining!
--
Pete
"Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!" | |
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melle
V4 Guru
United Kingdom
3833 Posts | Posted - 28 Mar 2019 : 23:11:34
| I cannot wait to have my daily 900 electrified.
www.saabv4.com | |
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andydeans3
V4 Guru
United Kingdom
2012 Posts | Posted - 29 Mar 2019 : 12:18:35
| Peter/Melle.
Not sure about the theory of the price of petrol dropping, when the electric car revolution really takes over.
The way I see it, as the "revolution" moves forward, and we reach the tipping point, when perhaps Electric cars start to cost the same as IC driven cars, and there is a great rush to electric, petrol stations will start to disappear like "snaw aff the dyke", as we say up here in the frozen North. (the "real" north, not that pretend one around Manchester, ha ha ha... ). A bit like the way that bank branches are disappearing now.
As less and less people need petrol, the transportation costs per volume of fuel shipped will rise steeply. Plus the government, (Bless their cotton socks), will massively increase the tax on fuel to encourage people to switch, also to compensate for their loss of tax revenue on selling fuel.
Using today's prices I could see petrol costing £10 or £15 a litre, once the switch to electric is in full swing.
Melle. I would happily convert my 96 to fully electric, except that it currently is prohibitively expensive.
I saw a You Tube clip of a guy in Germany with a fully electric 95, but it only had a range of about 80 miles. (Might even have been 80 kms - can't exactly remember).
Lead acid batteries I think.
I know in the MG world someone converted a modern MG-F (or TF) to fully electric, and I think it cost him more than £10 000.
There is a company now producing a brand new MGB fully electric car for, wait for it.......£99 000!!!!!!
(bearing in mind that given the supply of spares, including body shells, you can actually build a brand new MGB from parts.)
I have been looking at converting the 96 to GPL, which is likely to be around a lot longer than petrol, due to the it's many non automotive uses. That costs around £1000 to £1200.
My MGB, I'm going to sell shortly, (after 37 years boo hoo), once I get the Historic status for the car - it's a 1978 car.
So if you know anyone interested in buying a much loved MGB roadster - let me know.
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro |
Edited by - andydeans3 on 01 Apr 2019 16:02:54 | |
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melle
V4 Guru
United Kingdom
3833 Posts | Posted - 01 Apr 2019 : 19:05:24
| I'm not interested in having my V4s converted to electric, the engine for me is at least half the fun. That being said, I would welcome a ban on all internal combustion engines for obvious reasons, and I would happily give up this hobby in that case (plenty other hobbies left).
www.saabv4.com | |
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| Topic | |
Cold starting issues.
