Help on the engine
Discussion
Can anyone help me. I have a 280i wedge with a 2.8 v6 engine. No body on the wedge forum seems to be able to help.. i have been advised that we share the same engine from the capri.
What seemed to be happening was at very high revs in higher gears the car hesitated but ran perfectly in every other way, i was advised to change the fuel filter but this did not help.. I then changed the spark plugs and that sorted the problem. But now the car hesitates when driving at a constant speed like its missing, If you accelerate its all fine again until you settle to a constant speed again
So the problem is now i have to drive everywhere accelerating, also the car does not idle well, the leads all look ok and are good quality and fairly new.
Now this could be a coincidence but all my problems seemed to start when i switched to unleaded with additive from LRP, i switched back to lrp for a couple of tanks but did not cure it. so i went back to optimax. PLEASE HELP as this is my daily runner
>>> Edited by wedget on Tuesday 29th June 10:40
What seemed to be happening was at very high revs in higher gears the car hesitated but ran perfectly in every other way, i was advised to change the fuel filter but this did not help.. I then changed the spark plugs and that sorted the problem. But now the car hesitates when driving at a constant speed like its missing, If you accelerate its all fine again until you settle to a constant speed again
So the problem is now i have to drive everywhere accelerating, also the car does not idle well, the leads all look ok and are good quality and fairly new.
Now this could be a coincidence but all my problems seemed to start when i switched to unleaded with additive from LRP, i switched back to lrp for a couple of tanks but did not cure it. so i went back to optimax. PLEASE HELP as this is my daily runner
>>> Edited by wedget on Tuesday 29th June 10:40
If it was a 2.9 then I would say Throttle Pot but as you don't have one (do you?).....
It sounds like a timing type problem or possibly the idle valve. Maybe it is sticking and upsetting the fuel misture at idle and holding a constant speed.
Has the distributor been touched recently? The fact that it is OK accelerating would indicate that it is advancing OK but maybe it's not retarding fully for cruising and idling.
tricky one
Colin
It sounds like a timing type problem or possibly the idle valve. Maybe it is sticking and upsetting the fuel misture at idle and holding a constant speed.
Has the distributor been touched recently? The fact that it is OK accelerating would indicate that it is advancing OK but maybe it's not retarding fully for cruising and idling.
tricky one
Colin
Huuum, if it were a timing issue then I would expect the problem to get worse under load not better. Timing issues are usually progressive and usually rear their heads as a lack of power, or the dreaded pinging.
I would look at two areas, firstly the fueling. I am not familiar with the 2.8, but most injection (and carb for that matter), engines have an enrichment valve. This is used to increase fuel supply under acceleration, but not used under normal running. It may be that the sensor that detects the level of fuel to be supplied under normal load is not working properly (the pot that colin mentioned). There must be an equivalent on your car. As the enrichment valve is still working, so the car is ok under acceleration. This I think is most likely.
The only other thing I can think of is the ignition, so check the coil, at high rpm these can begin to break down (but I would expect this to also occur under acceleration).
I would also check all sensors and connections as a precaution.
Hope that helps,
Z
>> Edited by z_chromozone on Tuesday 29th June 13:12
I would look at two areas, firstly the fueling. I am not familiar with the 2.8, but most injection (and carb for that matter), engines have an enrichment valve. This is used to increase fuel supply under acceleration, but not used under normal running. It may be that the sensor that detects the level of fuel to be supplied under normal load is not working properly (the pot that colin mentioned). There must be an equivalent on your car. As the enrichment valve is still working, so the car is ok under acceleration. This I think is most likely.
The only other thing I can think of is the ignition, so check the coil, at high rpm these can begin to break down (but I would expect this to also occur under acceleration).
I would also check all sensors and connections as a precaution.
Hope that helps,
Z
>> Edited by z_chromozone on Tuesday 29th June 13:12
If its misfiring at idle as well then you can try pulling the plug leads one at a time. If one makes almost no difference to the misfire then check that plug/lead and the distributor.
If the misfire is totally random then check coil/ignition amp connections/ballast resistor.
After that I'd give the airflow meter a clean/spray WD40 etc.
If the misfire is totally random then check coil/ignition amp connections/ballast resistor.
After that I'd give the airflow meter a clean/spray WD40 etc.
With intermittent problems - it can be really hard to trace.. I personally would recommend taking the car to someone who really knows what they are looking for - you could end up replacing loads of stuff just by guess work.
When my 'ecu' went (V8) the fueling got really rich - so much so that it made your eyes water to follow the car !
Swapped the ecu with a friend (same model) and problem disappeared.
Don't know wnough about the 2.8 to comment - but I would say give Big Paul a call at Austec.
When my 'ecu' went (V8) the fueling got really rich - so much so that it made your eyes water to follow the car !
Swapped the ecu with a friend (same model) and problem disappeared.
Don't know wnough about the 2.8 to comment - but I would say give Big Paul a call at Austec.
Sounds very similar to the probs M@H had a few weeks back.
Might be worth dropping him a line if he doesn't see this thread
This is the thread it might help
www.pistonheads.com/gassing/topic.asp?p=1&f=11&t=101392&h=0
>> Edited by Pies on Tuesday 29th June 17:46
Might be worth dropping him a line if he doesn't see this thread
This is the thread it might help
www.pistonheads.com/gassing/topic.asp?p=1&f=11&t=101392&h=0
>> Edited by Pies on Tuesday 29th June 17:46
Indeed sounds just like my problem.... In my case it was mainly an air leak on induction.. the hose between the Airflow Meter and the Throttle Butterfly had small splits in it in places, accordingly when trying to get the engine idling, the car was drawing air through the splits enough to mean that it wasn't raising the air plate in the Meter, therefore the engine wasn't fueling enough... in all cases the fueling was wrong.. also check all the vacuum hoses as, for example, the vacuum feed to the warm up regulator is vital... if this hose has come off you will also get the symptoms you describe too.
Cheers,
Matt.
>> Edited by M@H on Tuesday 29th June 19:18
Cheers,
Matt.
>> Edited by M@H on Tuesday 29th June 19:18
wedget said:
the car is definately overfueling but only intermitently.
If its overfuelling then check the airflow meter. It wont overfuel if the hose is leaking. Does happen that the control valve and airflow plate pivots get dirty and stick, would give these symptoms.
While youre there check that the airflow plate closes centrally in the bore.
Wow i am very impressed with the feed back here, I think it may be the thing that all the fuel lines come from, I think it is called a Kollector, I have been told that they sometimes need a clean up as there is a valve inside that sticks, Unfortunately i cant go to pistonfest due to lack of funds. I am going to take off the Kollector and clean things up and hope that works....The finances are only a temporary thing and i am now walking to work, I think the school kids on my route will miss the wedge as much as me
wedget said:
I am going to take off the Kollector and clean things up and hope that works....
The airflow meter/fuel distributor are actually 'one-piece'. It will probably be enough (and a lot quicker)just to remove the hose from the airfilter from the airflow meter and spray WD40 up into the body of the airflow meter. This should clean up the pivots and joints between the sensor plate and the fuel distributor valve.
A good check list of possible faults is here www.forparts.com/techbosKjectronic.htm
I know some people who got on ok with using unleaded and additives and others that didn't. I don't believe that the additives neccessarily mix correctly, or in the right concentrations to be reliable, resulting in either to much or too little coating. My first action would have been to change the plugs, as they would be the first to suffer (which you did). The problem could now lie with the fuel system, as has been said, or the valve seats. At this point I would be tempted to run some fuel injector cleaner through the system. Possibly for the next 3 or 4 tankfuls of lrp, this should clean things up a bit (you could use one bottle per half tank to increase the strength a bit) . I find the STP stuff is good, generally I put one bottle in about once a month or so to keep things ok too. You may want to avoid the optimax for a while too, as this does not always enhance performance and as things are a bit off with your engine, it may actually make it worse.
Andy
Andy
Funny enough i put some of that Stp injector cleaner in it about a month ago and it made no difference, But i do highly recommend it myself as it has done wonders in the past. I do notice quite a difference with optimax but i will try normal unleaded for a while my car runs fine on both(no pinking) or would you sudgest i revert back to LRP. the reason i went from LRP was i heard it was not good quality. and i stupidly ran my car for about 2k with no additive on optimax this may have caused the problem to start with as it was around this time i noticed the first problem.
I'm assuming that the wedge doesn't have the unleaded heads and should therefore be running on leaded or lrp as standard. Running on unleaded (optimax, super unleaded or standard) even for 2k miles may have damaged the valve seats. If the seats are damaged you could get unburnt fuel in the exhaust causing the popping and very lumpy running. It needs further investigation with a pressure gauge to rule that out. Hoping it is nothing more than gunked up, use the STP regularly for a while, as it takes more than one to do the job.
Andy
Andy
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