Cold start problems...
Discussion
I don't know if this is normal, but when I first start my car it doesn't feel at all right for the first minute or so. Is it normal to find that there is less power even when pulling away relatively slowly (I'm not talking about putting my foot down, just pulling away normally)? I find it quite jerky, like the power is coming and going for the first little bit of driving, almost like it's getting close to stalling and then away again. If I press the accelerator harder it seems to exaggerate it, like the fuel is not igniting properly. It was particularly bad a week or two back when it was around zero degrees.
A couple of times now the car has also stalled after running for less than 30s and then refused to restart. Both times I have had time to move the car about 5m (out of my garage or a car park space) and then changed gear to pull away in the opposite direction and as I go to pull away it stalls and then refuses to restart. The first time I left it for a while and it then started ok. I wondered if I had flooded it (is this possible) by pushing the accelerator to hard to deal with the lack of power (as described above) the second (today) I was quite gentle with the accelerator (I have been since it first happened) so I can't believe it was that. I left it about 5 mins and tried again and still no luck. It was like it was almost starting on each turn of the engine and then having a mini stall. Eventually I thought I'd try pressing a little on the accelerator while I tried to start it and it fired up, but the revs were all over the place for a bit when I lifted my foot again. I kept it pressed for a little, keeping the revs at about 1800 and then moved off after about 20 seconds. Once I had gone a little further it was fine and after I got home and stopped it started normally.
Any ideas what this could be? If it's relevant, it takes anything from a couple to about 7 turns to start up normally, but I'm pretty sure it's not a battery problem. Any help would be much appreciated...
A couple of times now the car has also stalled after running for less than 30s and then refused to restart. Both times I have had time to move the car about 5m (out of my garage or a car park space) and then changed gear to pull away in the opposite direction and as I go to pull away it stalls and then refuses to restart. The first time I left it for a while and it then started ok. I wondered if I had flooded it (is this possible) by pushing the accelerator to hard to deal with the lack of power (as described above) the second (today) I was quite gentle with the accelerator (I have been since it first happened) so I can't believe it was that. I left it about 5 mins and tried again and still no luck. It was like it was almost starting on each turn of the engine and then having a mini stall. Eventually I thought I'd try pressing a little on the accelerator while I tried to start it and it fired up, but the revs were all over the place for a bit when I lifted my foot again. I kept it pressed for a little, keeping the revs at about 1800 and then moved off after about 20 seconds. Once I had gone a little further it was fine and after I got home and stopped it started normally.
Any ideas what this could be? If it's relevant, it takes anything from a couple to about 7 turns to start up normally, but I'm pretty sure it's not a battery problem. Any help would be much appreciated...
Sounds like it could be ignition related. You can easily flood the plugs if it turns over but doesn't fire. That may have caused a secondary problem. If you can get it going, it may be advisable to go for a good blast to thoroughly burn off any unburnt fuel & blow things through to drive off any dampness & moisture.
Original problem could really be a host of things. If you keep it outside, it could be dampness getting in & degrading the spark etc.
Check tightness & condition of all HT leads at both ends - don't forget the one to the coil. Check for any arcing (in a dark garage).
There is a bad batch of rotor arms around (as I found out after experiencing something similar to you!). If in any doubt, change it! Don't rely on condition - mine appeared fine but must have been sitting at the wrong height relative to the contacts in the cap os something. Changing it cured my problem.
The other problem could be timing. If it runs well after the run, it's probably not this though.
Good luck,
Mick
Edited to add: There's also cleaning of the stepper motor to try.
Original problem could really be a host of things. If you keep it outside, it could be dampness getting in & degrading the spark etc.
Check tightness & condition of all HT leads at both ends - don't forget the one to the coil. Check for any arcing (in a dark garage).
There is a bad batch of rotor arms around (as I found out after experiencing something similar to you!). If in any doubt, change it! Don't rely on condition - mine appeared fine but must have been sitting at the wrong height relative to the contacts in the cap os something. Changing it cured my problem.
The other problem could be timing. If it runs well after the run, it's probably not this though.
Good luck,
Mick
Edited to add: There's also cleaning of the stepper motor to try.
Edited by AlexanderV8 on Tuesday 8th January 21:53
nia198 said:
A couple of times now the car has also stalled after running for less than 30s and then refused to restart. Both times I have had time to move the car about 5m (out of my garage or a car park space) and then changed gear to pull away in the opposite direction and as I go to pull away it stalls and then refuses to restart.
Sorry, can't help with diagnosis but my car has always (mildly) acted up reversing when cold- especially in winter. Since I've owned it, therefore, I try to ensure I'm going forward from start-up. I don't know if it's a TVR thing but it's perfectly happy in reverse after a run.
Hi all
I agree about the need to "nurse" the car a little for the first 30 seconds or so, more so if you're reversing. It feels like a delay between pressing accelerator and the engine responding.
If I remember correctly (and this might not be for the 4.0+ models), there is a 5s cold start timer and 9th injector that adds fuel when the engine is cold, and every time you reset the ignition and crank again it sprays fuel into the plenum to help starting. If you are taking several tries for it to start then you could be flooding.
Agree with points about ignition though - it shouldn't be taking several tries to get it to fire.
I agree about the need to "nurse" the car a little for the first 30 seconds or so, more so if you're reversing. It feels like a delay between pressing accelerator and the engine responding.
If I remember correctly (and this might not be for the 4.0+ models), there is a 5s cold start timer and 9th injector that adds fuel when the engine is cold, and every time you reset the ignition and crank again it sprays fuel into the plenum to help starting. If you are taking several tries for it to start then you could be flooding.
Agree with points about ignition though - it shouldn't be taking several tries to get it to fire.
Has the car been serviced recently?
This problem can happen if the fuel pressure is too high, but it can also happen if the plugs are very dirty or there is any ignition problem leading to a weaker spark than normal.
In this case just the extra acceleration enrichment when you open the throttle can be enough to drown it. Until you get the problem sorted out I suggest you treat the engine very carefully for the first few minutes after a cold start, use as little throttle as possible but just gently ease the revs up to 2000 rpm or so and hold it there until it will run cleanly. If it starts bogging down when you try to open the throttle, you need to let it sit at fast idle a little longer to get more heat into the plugs.
This problem can happen if the fuel pressure is too high, but it can also happen if the plugs are very dirty or there is any ignition problem leading to a weaker spark than normal.
In this case just the extra acceleration enrichment when you open the throttle can be enough to drown it. Until you get the problem sorted out I suggest you treat the engine very carefully for the first few minutes after a cold start, use as little throttle as possible but just gently ease the revs up to 2000 rpm or so and hold it there until it will run cleanly. If it starts bogging down when you try to open the throttle, you need to let it sit at fast idle a little longer to get more heat into the plugs.
Yes - was serviced not long ago and is being used regularly.
Thanks for all the ideas. Will have a poke around at the weekend and if I can't find anything myself will take it into the garage and see what they can find. Still takes 6 or 7 turns to get it going, but otherwise it's been fine since I initially posted this! Seems to come and go...
Thanks for all the ideas. Will have a poke around at the weekend and if I can't find anything myself will take it into the garage and see what they can find. Still takes 6 or 7 turns to get it going, but otherwise it's been fine since I initially posted this! Seems to come and go...
FWIW as previously mentioned, my '99 Chim always bogs down when cold started on cold days for the first minute or so - I leave it to idle for this time. I presume it's waiting for the engine to get just warm enough to come off the cold-start program. After that it runs absolutely fine.
However, mine does usually starts within about 2-3 turns.
However, mine does usually starts within about 2-3 turns.
The cold start "program" you refer to is very simple. It simply has fixed injector pulse widths for about 4-5 seconds on cranking (Ie it ignors the airflow meters input.)It also winds the stepper motor back (ie opens up the airflow) when you turn the igition off, so thats why you tend to get a quick rpm rise on restarting. If the car first fires ok, but then wont idle, look for air leaks in the Plenum area, as this can cause a low air flow reading, so the amount of fuel is wound back and the car wont run. It would be worth taking a plug out when it wont run correctly to see if its black from overfueling as well. Some fuel maps out there overfuel on start up as well and I know its an issue Mark Adams address's with his remaps. Another check is the reading from the temparature sender, this has a huge effect on the amount of fuel going in.
Mark
Mark
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