Cold start problem?
Cold start problem?
Hi there,Just a quick Hello to introduce myself,the name is Theo,and have just bought my first Volvo,a 1986 360 GTL with body kit,and Boy am I wrapt!Most fun I've had in a long time!One question though,from cold it runs like **** then clears itself after 10 seconds or so,then runs nicely until its stone cold and problem recurs,isthis common?Cheers
Hello, and welcome. I'm afraid its a very common problem and its down to the stupid useless fuel injection system. Its a bit agricultural and old fashioned and always seems to overfuel on cold starts a bit.
If it really splutters badly then there's something wrong, with either the connection to the temperature sensor in the cylinder head (Its the second sensor in from the rear of the cylinder head), or the plug to the ECU, if there's any corrosion and poor contact it results in the ECU seeing too cold a temperature and overfuelling.
If it really really struggles to run and the sensors are OK there's a possibility the ECU itself is duff, probably leaky electrolytic capacitors. I think one of mine has got this problem, occasionally it'll fire only on 3 cylinders for a few seconds on startup from cold. I had the ECU tested and it failed on overcurrent on standby, but I've struggled to find what component has failed, and I'm certainly not paying someone else too much money to do so
If its just a bit lumpy then that's a design fault and everything's working fine. I did do a fix for it a couple of years back to fool the ECU into seeing a higher temperature which completely cured the problem. It involved a capacitor and resistor connected to the coolant temperature sensor but I can't remember where I've put it or what the values were.
That was supposed to be a short post but its ended up being a rambling long one........ hope it helps anyway.
If it really splutters badly then there's something wrong, with either the connection to the temperature sensor in the cylinder head (Its the second sensor in from the rear of the cylinder head), or the plug to the ECU, if there's any corrosion and poor contact it results in the ECU seeing too cold a temperature and overfuelling.
If it really really struggles to run and the sensors are OK there's a possibility the ECU itself is duff, probably leaky electrolytic capacitors. I think one of mine has got this problem, occasionally it'll fire only on 3 cylinders for a few seconds on startup from cold. I had the ECU tested and it failed on overcurrent on standby, but I've struggled to find what component has failed, and I'm certainly not paying someone else too much money to do so
If its just a bit lumpy then that's a design fault and everything's working fine. I did do a fix for it a couple of years back to fool the ECU into seeing a higher temperature which completely cured the problem. It involved a capacitor and resistor connected to the coolant temperature sensor but I can't remember where I've put it or what the values were.
That was supposed to be a short post but its ended up being a rambling long one........ hope it helps anyway.
Hmmm, bet I don't still have the LE jet diagram we had scrawled things on either Andy... That did seem to work awesomely in your car though.
Did you remove the orig cold start RC, and just replace it with something else that was calculated either longer or shorter....
Did you remove the orig cold start RC, and just replace it with something else that was calculated either longer or shorter....
'89(G) 340 GLE B172k
'03 S60 D5 SE, '91 (J) MX5, 1954 Cyclemaster
Ex:
'89(F) 340 GL F7R (ex B172k) - Fake -> SBKV 300 Runner Up 08, 12; '91(H) 340 GL B14.4E - Kar; '88(F) 360 GLT B200E - Jet -> BKV 300 Runner Up 09; '89(G) 360 GLT B200E - Beast
'03 S60 D5 SE, '91 (J) MX5, 1954 Cyclemaster
Ex:
'89(F) 340 GL F7R (ex B172k) - Fake -> SBKV 300 Runner Up 08, 12; '91(H) 340 GL B14.4E - Kar; '88(F) 360 GLT B200E - Jet -> BKV 300 Runner Up 09; '89(G) 360 GLT B200E - Beast