Hello,
Recently I decided to tackle my dad's E30, to bring back a bit of the engine's lost power. We have registered it as "Antique" here so it's like staying in the family forever..
Car's an E30, M40B18, with exactly 300000km on the odo. The engine has never been tampered with, other than the usual service items: hoses, timing belt, tensioner, belts, oils, spark plugs, a couple of waterpumps, fuel pumps, ICV and filters (ignore the k&n sticker). Throttle body switch is at correct position (not being pulled by throttle cable)
I have tried to capture its behavior on video, with the link below, when starting either cold or hot it is "missing" every couple of seconds. This is not only on idle but across the rpm range. Obviously car feels very sluggish the very least.
I am considering changing the distributor cap as a start. Is this a good approach?
M40B18 refresh & bringing it back to life
Moderator: martauto
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
As with most of these videos, all I can hear is what sounds like a reasonably healthy diesel engine!
You're quoting the odometer in km, so I suspect this is not a UK car, and your user name might also be a clue?
Do you have a lambda sensor on this car? It would be unusual to have one on a UK car, but where you are they might be more common.
At 1:38 into the video, you can see a small bore rubber hose emerging from under the inlet manifold and ending in what looks like loosely wrapped insulating tape. This hose is part of the emissions reduction equipment on cars with lambda sensors fitted, and goes to a solenoid operated air valve, but on cars without this equipment fitted it just hangs as yours does, BUT the end of it must be completely sealed with a plug.
At 300,000 km the injectors are due for a rebuild if they are the originals. Each will have operated around 400,000,000 times by now, and are likely to be flowing considerably less fuel than they should be.
If oil changes on these engines are neglected, then they do wear their camshafts, but the effect of this is for the engine to act as if it has a rev. limiter at 3000 - 4000 RPM.
The distributor cap and rotor on your engine may or may not be past their best, but I wouldn't associate what you describe with ignition problems. Problems here on the M40 tend to manifest themselves as a soft misfire when accelerating.
One thing I have seen that might fit your description is a faulty DME relay. You can check this at no cost by pulling it out and using a couple of wire links to connect together pin 30 and both pins 87 of its socket, and driving the car as normal.
Having the links in place is the same as leaving the ignition switched on, so don't forget to remove them when you stop the engine.
You're quoting the odometer in km, so I suspect this is not a UK car, and your user name might also be a clue?
Do you have a lambda sensor on this car? It would be unusual to have one on a UK car, but where you are they might be more common.
At 1:38 into the video, you can see a small bore rubber hose emerging from under the inlet manifold and ending in what looks like loosely wrapped insulating tape. This hose is part of the emissions reduction equipment on cars with lambda sensors fitted, and goes to a solenoid operated air valve, but on cars without this equipment fitted it just hangs as yours does, BUT the end of it must be completely sealed with a plug.
At 300,000 km the injectors are due for a rebuild if they are the originals. Each will have operated around 400,000,000 times by now, and are likely to be flowing considerably less fuel than they should be.
If oil changes on these engines are neglected, then they do wear their camshafts, but the effect of this is for the engine to act as if it has a rev. limiter at 3000 - 4000 RPM.
The distributor cap and rotor on your engine may or may not be past their best, but I wouldn't associate what you describe with ignition problems. Problems here on the M40 tend to manifest themselves as a soft misfire when accelerating.
One thing I have seen that might fit your description is a faulty DME relay. You can check this at no cost by pulling it out and using a couple of wire links to connect together pin 30 and both pins 87 of its socket, and driving the car as normal.
Having the links in place is the same as leaving the ignition switched on, so don't forget to remove them when you stop the engine.
Only that is a petrol lol.. About 16-17 years ago it switched to unleaded fuel from leaded if it matters.. I'm in Cyprus, car was purchased brand new in 1989. I will check first thing tomorrow morning that small bore hose. Car does not have any emissions control system.Brianmoooore wrote: ↑Fri Jun 12, 2020 11:37 pmAs with most of these videos, all I can hear is what sounds like a reasonably healthy diesel engine!
You're quoting the odometer in km, so I suspect this is not a UK car, and your user name might also be a clue?
Do you have a lambda sensor on this car? It would be unusual to have one on a UK car, but where you are they might be more common.
At 1:38 into the video, you can see a small bore rubber hose emerging from under the inlet manifold and ending in what looks like loosely wrapped insulating tape. This hose is part of the emissions reduction equipment on cars with lambda sensors fitted, and goes to a solenoid operated air valve, but on cars without this equipment fitted it just hangs as yours does, BUT the end of it must be completely sealed with a plug.
At 300,000 km the injectors are due for a rebuild if they are the originals. Each will have operated around 400,000,000 times by now, and are likely to be flowing considerably less fuel than they should be.
If oil changes on these engines are neglected, then they do wear their camshafts, but the effect of this is for the engine to act as if it has a rev. limiter at 3000 - 4000 RPM.
The distributor cap and rotor on your engine may or may not be past their best, but I wouldn't associate what you describe with ignition problems. Problems here on the M40 tend to manifest themselves as a soft misfire when accelerating.
One thing I have seen that might fit your description is a faulty DME relay. You can check this at no cost by pulling it out and using a couple of wire links to connect together pin 30 and both pins 87 of its socket, and driving the car as normal.
Having the links in place is the same as leaving the ignition switched on, so don't forget to remove them when you stop the engine.
Yes, injectors are the original, never touched. Added to the parts list, at their age might as well replace them. Oil change has always been on time, semi-synthetic 10W40 since purchase along with the filter.
Also added the DME relay to the checklist, many MANY thanks, will do the above and report back!
So I went ahead and removed that piece of hose for the emissions control - was falling apart - and blocked the port using a small piece of rubber hose with one end capped with a steel ball. Made no difference unfortunately. Drove the car and apart from the misfiring symptoms it appears as completely torqueless which obviously is related with the general sluggish symptoms. Although I'm not expecting extraordinary torque from an M40, it should at least be able to maintain some acceleration throughout the gears. 125km/h on going uphill motorway will slowly drop to 105km/h.
I'm presented with an option for full engine (and differential as it whines) rebuilt, including new camshaft, rings, all rubber hoses etc. These at a cost of €1200 incl. labor. Doesn't seem much and should make the engine good for another 300k I assume.. I really wanted a B25 upgrade but they are nowhere to be found.
I'm presented with an option for full engine (and differential as it whines) rebuilt, including new camshaft, rings, all rubber hoses etc. These at a cost of €1200 incl. labor. Doesn't seem much and should make the engine good for another 300k I assume.. I really wanted a B25 upgrade but they are nowhere to be found.
