fingers crossed sombody can help with this one i have a 200 gt Rcz that is pretty poorly its had new rings and bearings everything was checked and was within tolerences its had a new Maf/Map/Boost pressure sensor and both 02 sensors ive done a compression test and it shows 160 on each cylinder yet it just will not run nicely and keeps throwing lean codes im wondering if the vanos control motor is out of whack as it had to be swapped out as the connector got broken off when the head was being skimmed (machine shop supplied new part and i installed it) ive attached a readout from the car i did think maybe the fuel pump was nackerd but on inspection its gat a 2019 date stam on it so i would have thought it is ok.
If it's running lean you have a vacuum leak somewhere around the intake or rocker squirty bottle with strong washing up liquid and water listen for possible hissing noises and squirt accordingly. The values you show don't look particularly bad .you need to graph your fuel trims to see if to see how far out they are.anything outside +/- 10 will tell give you better direction.
Hey the thanks for the reply the fuel trims stay maxed out at 25% on both st/lt on upstream and a steady 625mv on the downstream I've been all over it with a propane torch and can't find any vac leaks I think the vanos system isn't completely closing the intake valves at idle. I'm going to try and reset the adaptions tomorrow to see it makes any difference.
ok so this morning ive done a leakdown test on the engine its showing less than 3 % on each cylinder which could be the cheap gauge ive got but its still well within specs as ive seen on other sites that anything upto 20% is ok on somes boosted motors im going to run the engine upto tempreture and try resetting the adaptions on the vanos drive solonoid to see if it changes anything else looks likee the fuel pump is goosed after less than 12000 miles.
well with that high of positive fuel trims and no obvious leaks it could be your EGR stuck open. try taking it off and give it a good clean. Failing that it could be a bad O2 lying to the ecu which would make it run like crap. other possibility is a leaking brake booster.
It would be good to tell us about the background to you needing to get the engine rebuilt and what the inspection revealed. At 180,000 km I can imagine that it would be pretty sooty with valve guides and oil rings suspect, as well as sooty inlet ports and valves, and maybe exhaust as well? How was the compression? Out of curiosity, were any compression rings seized? Was the head dismantled to allow replacement of the valve guide seals? Was there any concavity in the cylinder head and how flat was the block face. Was the hardness tested?
In the two engines I have overhauled they ran very badly for about half a dozen starts before the ECU sorted things out. I never knew how to set the stops for the eccentric cam controlling the valve lift but the car eventually sorted itself out.
I'm not familiar with much of the data presented but it looks to me that your inlet Vanos position agrees with the desired reference value and that there is nothing wrong with the pressures generated by your HPFP.
It is not unknown that the Vanos units can be put on the wrong shaft, although they are clearly marked. It is also possible to muck up the valve timing - there is more than one hole in the flywheel into which the crankshaft timing pin can be inserted, and you should check the height of all 4 pistons is the same when the pin is inserted. You can just about tell by eye if the flat tops of the camshaft timing lugs are horizontal with the face of the head but of course it is much better to use the correct tool. If everything checks out ask the mechanic how they held the camshafts still while they did the 180 degrees angle torque on the end retaining bolts. There are astute people who advise against using the 27mm hexagons that hold the camshaft position sensor assembly to the other end of the camshaft for fear that you may alter the position of the timing assembly on the camshaft. I don't think you can recover from this and I'm not sure how you would check it.
There is also scope for wear in the variable valve lift eccentric shaft to cause engine running problems but if this assembly was dismantled any excessive wear would have been noticed.
As I am aware the head was checked and found to be ok the car came to me with a cylinder 1 missfire on inspection the head gasket was found to be bad on that cylinder the rings and bearings where replaced as I was advised with the milage they where likely due replacement everything was checked and was all within tolerance when reassembled the block needed to be honed and skimmed as it was slightly untrue over cylinder 1 the head was checked over and was found to be ok I was told it didn't need any work as it appears the previous owner had already had the valve stem seals replaced (I have a receipt for the work but strangely it doesn't say anything about the head gasket being replaced just the valve stem seals and a walnut blasting)
The back of the valves looked spotless before the engine was put back in the car I have done a leakdown test today and it shows around 3% leakage and a compression test is showing 160-165 across the cylinders and I've reset the vanos control solonoid motor adaptives and it definitely runs better but I'm still getting cylinder 4 missfire.
so after a late evening of trouble shooting ive still got a missfire on cylinder 4 and ive noticed that if this diagram is correct that it appears the radiator pipes have been put back on the wrong way round as service box says they go the other way so im a little confused thinking maybe ive killed it now installing it backwards.
If all you have done is change the direction of flow in the radiator I wouldn't be too concerned! And since it looks like there are no branch lines on both these hoses the flow in any ancillaries would not have been affected. The large diameter thermostat outlet at 9 o ' çlock closest to the head has an arrow facing out- that goes to the radiator inlet. The one just out from that is the return. As I understand it the thermostat controls the temperature of the water entering the coolant return pipe that runs behind the engine to the water pump. This pumps the water into the block. The temperature sensor monitors the temperature of the water leaving the cylinder head.
I now see that you have had a garage carry out extensive work on your engine. No one is perfect- you may well be dealing with a problem with the reassembly of the engine. You need to know precisely what they did.
Re " the car came to me with a cylinder 1 missfire on inspection the head gasket was found to be bad on that cylinder". On French cars cylinder 1 is at the gearbox end - for Germans using the same engine that cylinder is 4. Which end of the motor was the gasket bad at? How did your garage determine that there was a problem- you don't go ahead and remove the head gasket lightly on these engines. And what was actually the problem with the gasket- a coolant issue or a compression problem?
"the rings and bearings were replaced as I was advised with the milage they were likely due replacement everything was checked and was all within tolerance". At 180k km that is fair enough, especially for the rings, but what bearings were replaced- big ends or mains or both? Main bearings are generally long lasting and require a lot more effort than replacing the big ends. And what was the condition of the original bearings- that would give you an insight into the service history of the vehicle.
"the block needed to be honed and skimmed as it was slightly untrue over cylinder 1". Cylinders get honed, generally by hand. Flat surfaces get skimmed, generally by a machine. Skimming the face of the block is an engine-out procedure. What did they actually do?
"the head was checked over and was found to be ok I was told it didn't need any work as it appears the previous owner had already had the valve stem seals replaced (I have a receipt for the work but strangely it doesn't say anything about the head gasket being replaced just the valve stem seals and a walnut blasting) ". That would imply that the garage used by the previous owner was able to replace the valve stem seals with the head in place, which is very efficient. But they would have had to dismantle the complicated inlet camshaft with its variable lift /eccentric cam mechanism which is not trivial. The exhaust camshaft is relatively easy. Thus they would have been able to insect the journals and their bearing housings to be sure that there was not excessive wear which can cause fatal engine running problems. But you would not have this information, and your garage did not have to dismantle the head. One thing you can do is to remove the engine cover and make absolutely sure that the ends of the variable valve lift springs are correctly situated in the recess in the intermediate rocker shaft arms. You need a small inspection mirror for this. And a lot of patience. There are videos on You Tube. While you have the cover off, buy a cheap camshaft setting tool kit and check the timing- again there are many videos on this, some erroneous. And check the inlet and exhaust camshaft markings as well as the markings on the Vanos units to check that all are in the right place. Admittedly the engine would probably have self-destructed if they weren't but assume nothing.
Ok so I have had a look at the springs that you mentioned they all appear to be situated properly I have the tools necessary to lock the engine timing off and all appears correct I did notice some blueing of the exhaust camshaft at the vacuum pump end I removed the fuel pump and sent it off for repair as it appeared all the oil had been lost (the diaphragm was 28mm from the opening) which was confirmed by the person who repaired it since refitting it seems to run somewhat better but still a bit rough at idle (I've ordered a new lexia to reset the learned fuel adaptions) hopefully that solves the issue with the idle.
The car came with a confirmed missfire on cylinder 1 gearbox end the place I had the engine done by have said the gasket had failed on that cylinder I have spoken to him since and he has confirmed the block was not true over cylinder 1 he said the head was fully inspected and is ok he didn't want to disturb the inlet camshaft gear (he's an old boy more used to dealing with classics) I trust him though having had my Astra vxr engine rebuilt to 450hp by him he said the bearings looked pretty good for the milage and probably didn't need changing the block was fully disassembled and put on a machine to be honed and skimmed the rings were King rings (not sure what that means)
I'm hopeful that it smooths out once I can reset the adaptives fingers crossed.
Here goes the cars been back to the fella that done the work for me he has gone over it from top to bottom and says there is nothing wrong with it (mechanically) we have gone through the system using his snap on tool and for some wierd reason weve found that the issue is being caused by the MAF sensor (brand new Bosch unit) if we unplug it the car runs totally smooth and the fuel trims drop back to normal and the exhaust emissions drop to acceptable levels as soon as it's plugged back in the car either stalls when it's warn or idles like a pig from cold until it's warm then stalls if I leave it unplugged the car is also not showing and fault pids for it being disconnected we are starting to think the DME is knackered also the cooling fan runs on slow setting as soon as the car is started but doesn't stay on once the keys are removed not sure if it's normal for this to happen.
Very interesting. I have no idea why the block face would suffer damage but your garage sounds like it has done a thorough rebuild. On the petrol engines I wasn't aware that they have a MAF (airflow) sensor as such but rather a MAP pressure sensor? And I didn't see any MAF output on your monitoring data above?
But I agree that you would think the DME would be telling you that it was unplugged. Maybe some monitoring of the intake pressures plugged and unplugged would help?
We have success the car is running and passed it's MOT yesterday after all the work on it I found the issue at last so here goes.
The car came up with a couple of MAF codes after running it for a few days on a private road the idle was still bad and it was stalling out when coming to a stop so I decided to investigate the pcv system I managed to find a used knackered (cracked) rocker cover and stripped it to pieces so I could see what a working one looked like I spent a hole 3 hours cutting it up and then moved on to my 1 I removed the plastic cover on the diaphragm and low and behold the little red tophap was gone nowhere to be found I didn't even know it was ment to be there until I stripped the broken 1 and found it on that 1 and you wouldn't believe the difference a little cap could make to the way the car runs after maybe 5 mins putting the diaphragm cap back on I turned the key and boom it's alive purring like a new car. Now I've just got to hope after sticking some hard miles on it the rings will bed in ok after all the messing about.
