I have an 1989 s2 cab, pre cat, no O2 sensor.
100k miles now, do 2-3k a year in the summer, it is pretty much untouched motor wise, had it's belts done about 6 years ago, but the rest is original never been undone form the factory. Just get it out each may, sticka battery on it, MOT it and off I go!
Anyway, all was fine this year, but this week it seemed to be susing a bit too much fuel and I notcied the back of the car was a bit sooty round the exhaust. BUt was due a service, plugs etc, so didnt think too much. Then last night, went to start it, and it was misfiring on start, very rough running on the gas, revving it up just stuck loads of balck smoke out the back and some blue too (blue smoke has been normal tbh on this car, for years, I think due to old valve stem seals, but after 30m secs it all clears and has always run fine). After much revving it settles down and runs on 4 again, and settles down to a perfect 900rrm idle. Drive the car, very fluffy, lots of black out the back, but open her up and it clears and goes fine. BUT on the overun, it seems to pop a bit out the exhaust...then come to a junction and the idel is all over the shop, 900drop to 250rpm, back up to 900, horrible.
So now it seems the cold start is rough and it runs very rough after first start, need gas to get it to start too. BUT, once it is going, it idels fine, then as it warms, idel goes to pot.
My thoughts popping on overun could be weak mix, maybe rich too, but usually weak. Cold idel suggests it is rich mix, and poor idle when warm suggest rich too..? I pull the plugs, they are jet black, sooty soo and sos! Now I know where ll the fuel has gone!
Done lots of searchin on here at Clarks.
Pulled the ICV pipe off the rubber boot from AFM earlier, and it is sucking lots of air through there, from cold. so looks like the ICV is not blocked at least. And suggests it is open, blocking the pipe makes it stall or run rough.
checked all vaccuum pipes, all look ok, and pulling the vac pipe off the vac reservoir up by OS windscreen pillar and it pops, suggesting it is holding VAC in there.
Going to change the DME temp switch as it is cheap.
ICV is not cheap!
Also, suggestions that it may be fuel pressure reg, causing very rich mix, but surely if these fail, they fail open and just return all the fuel to the tank, loosing pressure in the rail. It runs ok under load and high revs, so unless it has failed "shut" and the fuel pressure is goign ape and too high at idel, I am not sure.
So anyone had these symptoms.
Rough cold start, missing that clears, lots of sooty smoke out the back. But when clears it will idel ok.
Drives a bit fluffy, but power is there, but then as warmed, pops on the overun a bit, then wont idle.
Using too much juice and sooty plugs.
FPR? Fuel Damper? DME relay? DME temp swich? ICV (idel stabiliser) ? AFM??
Where best to start?!?
Any help appreciated.!!
cheers
100k miles now, do 2-3k a year in the summer, it is pretty much untouched motor wise, had it's belts done about 6 years ago, but the rest is original never been undone form the factory. Just get it out each may, sticka battery on it, MOT it and off I go!
Anyway, all was fine this year, but this week it seemed to be susing a bit too much fuel and I notcied the back of the car was a bit sooty round the exhaust. BUt was due a service, plugs etc, so didnt think too much. Then last night, went to start it, and it was misfiring on start, very rough running on the gas, revving it up just stuck loads of balck smoke out the back and some blue too (blue smoke has been normal tbh on this car, for years, I think due to old valve stem seals, but after 30m secs it all clears and has always run fine). After much revving it settles down and runs on 4 again, and settles down to a perfect 900rrm idle. Drive the car, very fluffy, lots of black out the back, but open her up and it clears and goes fine. BUT on the overun, it seems to pop a bit out the exhaust...then come to a junction and the idel is all over the shop, 900drop to 250rpm, back up to 900, horrible.
So now it seems the cold start is rough and it runs very rough after first start, need gas to get it to start too. BUT, once it is going, it idels fine, then as it warms, idel goes to pot.
My thoughts popping on overun could be weak mix, maybe rich too, but usually weak. Cold idel suggests it is rich mix, and poor idle when warm suggest rich too..? I pull the plugs, they are jet black, sooty soo and sos! Now I know where ll the fuel has gone!
Done lots of searchin on here at Clarks.
Pulled the ICV pipe off the rubber boot from AFM earlier, and it is sucking lots of air through there, from cold. so looks like the ICV is not blocked at least. And suggests it is open, blocking the pipe makes it stall or run rough.
checked all vaccuum pipes, all look ok, and pulling the vac pipe off the vac reservoir up by OS windscreen pillar and it pops, suggesting it is holding VAC in there.
Going to change the DME temp switch as it is cheap.
ICV is not cheap!
Also, suggestions that it may be fuel pressure reg, causing very rich mix, but surely if these fail, they fail open and just return all the fuel to the tank, loosing pressure in the rail. It runs ok under load and high revs, so unless it has failed "shut" and the fuel pressure is goign ape and too high at idel, I am not sure.
So anyone had these symptoms.
Rough cold start, missing that clears, lots of sooty smoke out the back. But when clears it will idel ok.
Drives a bit fluffy, but power is there, but then as warmed, pops on the overun a bit, then wont idle.
Using too much juice and sooty plugs.
FPR? Fuel Damper? DME relay? DME temp swich? ICV (idel stabiliser) ? AFM??
Where best to start?!?
Any help appreciated.!!
cheers
