Archived Message
Power/exhaust emission problem warm engine
First of all a short introduction of myself. My name is Oliver and I am from Germany. After driving a MGF for 16 years, I bought a RV8 last year. Woodcote Green and Japan spec, a 1995 model.
Now my problem. When the engine is cold, everything is fine. But after a few minutes of running/driving, the exhaust emission values are no longer OK (lambda value doesn't fit). The temperature gauge is going to the middle position very fast (after less than 1 km driving). And in case of acceleration the engine doesn't have full power in the first two gears. You could also hear misfires. Motor speed is limited to max. 4000 rpm. In 3rd gear everything is fine again.
I have already replaced complete ignition equipment (sparks, leads, coil, module). I also replaced the fuel pressure regulator, fuel filters, fuel pump and the fuel temperature sensor . Injectors were also cleaned and tested. No success. The sparsk are white colored, mixture too lean. Now my local dealer changed the coolant temperature sensor. It was a lot of work, since the mentioned sensor with part number ETC8496 doesn't fit. The screw thread diameter is too small. The former inserted sensor looks like the fuel temperature sensor. So he built an adapter. After connecting the wirings again, the fan starts running immediately when ignition is set to on, no engine running. The fan doesn't stop, when engine was running. I really do not know, what elso to do? Maybe some of you have had a similar problem and can help. Thanks in advance and best regards,
Oliver Libuda
29/08/2012 @  18:47
Under topic: RV8
Archived Reply(ies) received for this Message
Power/exhaust emission problem warm engine
Hi Oliver.
Have you tried cleaning the Stepper Motor as this will cause the engine to run eracticly,as for your heating and fan problems has a previous owner done any modifications that you know of? The temperature guage normally runs in the middle almost from the start but does it go into the hot position only then do you need to worry. I hope that this might help!
John Bolt, RV8 Historian
30/08/2012 @  20:54
Power/exhaust emission problem warm engine
Hi John,
I also cleaned the stepper motor and as far as my dealer told me, it works fine.
I will check whether the previous owner did any modification on the fan or the temperature sensor. Many thanks also for the information, that it is normal, that the gauge will react in that fast time. It doesn't go into the red level/hot position. I will keep you updated, if I receive any more information from my dealer or the previous owner. Thanks and best regards,
Oliver Libuda
30/08/2012 @  23:47
Power/exhaust emission problem warm engine
In my opinion, Oliver your problem has nothing at all to do with your cooling temperature. I would put that part of your problem to one side for the time being. The fact that your fan is continually running is due to a wrong connection which the last workshop must have made. Your RV8 is backfiring and you have no power which is twofold (it won't go over 3000 revs so fuel or ignition). This means you will have to look again at the fuel supply. Is it reaching the fuel pump or not? Is the priming pump (the one at the rear) really functioning? Last, but not least, have you really checked the ignition your advance and retard system functioning or not and is the timimg set correctly? I would strongly advise you to take the car to a Bosch outlet and get it checked electrically first of all.
Peter Garton
31/08/2012 @  02:28
Power/exhaust emission problem warm engine
Fuel pressure was measured several times and is OK. Advance and retard system is also OK. I am still wondering why I just have the problems when engine is warm and there are no issues when driving faster (3rd gear up). Next steps will be to check signals which are reaching the ECU to be sure that all wires are fine. And of course we will also check the ignition again. Maybe not correct working ingnition coil, even when already replaced. Thanks for help.
Oliver Libuda
31/08/2012 @  03:19
Power/exhaust emission problem warm engine
You have nearly answered your problem. When your engine is pulling hard ie. in a lower gear you have no power and it is back-firing as I understood your information. This is normally a result of faulty ignition since you have apparently eliminated the fuel flow as a possible cause, Oliver.
Peter Garton
31/08/2012 @  03:50
Power/exhaust emission problem warm engine
A sticky stepper motor will not cause a weak mixture; its function is to control the idle speed, if it sticks open the idle speed will be high and if it sticks closed the engine may stall or have a slow idle speed. If itís just sticky you could have both high and low idle speed problems but the engine will run well if the throttle is open.

You or your dealer seem to have checked most things but the correct coolant temperature sensor should have fitted without any problems so there is something strange there. Is the new sensor a pattern part? A couple of things that you donít mention; the airflow meter and throttle position sensor, faults in either can confuse the ECU but if your dealer is a Land/Range Rover dealer or somewhere that knows the Rover V8 engine they will be able to check for faults.

It sounds like there are wiring faults so I would start by making sure all the sensor plugs are clean and well connected Ė check that No. 1 injector and the coolant temperature sensor plugs have not been exchanged; they will fit and the engine will still run.

A Japanese spec engine must also have the vacuum advance re-routed and the ignition timing adjusted Ė has this been done?
Geoff King
31/08/2012 @  06:00
Power/exhaust emission problem warm engine
I entirely agree with Geoff. The stepper motor is not the cause of your actual running problems, Oliver. The advance tubing won't be either. This will only improve the timing since the RV8 cars run like that all over Japan without problems . . . . . I drove one in Tokyo! I come back to my suggestion that Bosch check all your electrics again thoroughly. It is as if your ignition is running fully advanced. I wanted to ask whether these problems have suddenly appeared after the car was running normally.
Peter Garton
31/08/2012 @  14:15
Power/exhaust emission problem warm engine
Also check the air hoses for leaks; particularly between the airflow meter and the plenum, to the throttle by-pass valve (or stepper motor as itís called here) and to the servo. Make sure the crankcase breather is clean too.

I canít comment on Bosch but the Efi is a simple system so they shouldnít have any difficulty checking it. However, if Bosch is like your usual dealer or garage it is the individual doing the work that either knows what he is doing or doesnít. If I had to Iíd take my car to a Land/Range Rover specialist before I took it to Bosch, but thatís just me.

Good luck and please let us know how the problem is solved.
Geoff King
31/08/2012 @  14:55
Power/exhaust emission problem warm engine
The suggestion of using a Land Rover specialist familiar with Rover V8 Efi engines is good, but Oliver is in Germany and as Peter Garton lives there too, he has personal experience of finding a reliable source of specialist services to maintain his RV8. So given Oliver has explained he is struggling to solve the problems with his RV8, Peter's recommendation to visit a Bosch service provider is I feel an attempt to help Oliver try and solve the problem locally as Peter has seen that Bosch have performed well for him. I accept the abilities and experience of the mechanic are vital. If Oliver can find a Land Rover specialist in Bavaria then that will also be an option. I feel Oliver's case has reached a stage where the aim is to get him to someone who knows the engine and can identify the problem, then solve it.
Victor Smith
31/08/2012 @  16:06
Power/exhaust emission problem warm engine
Thanks to all of you for giving tips and possibilities and offering your detailed help what elso to be checked. Today in the morning I called my dealer and asked him again to check the ignition "settings". Since he was/is an official MG Rover dealer, I hoped he has enough experiences with the Rover V8 engine, but in the meanwhile I don't trust in him any longer. Therefore the check of the ignition would be his last action. Since it is raining cats and dogs today here in bavaria, I will catch my car next week from him independent if the car is running or not and will try another address to get my car running fine again.
Yesterday I also contacted the japanese dealer and asked him, if there were any problems or modifications during the japanese time of my RV8. Answer was no. He also recommended to have a look on ignition.
And of course I will keep you up to date about the progress.
Thansk again to all of you. It also helps for my current emotional state, which is not really fine :-)
Kind regards
Oliver Libuda
31/08/2012 @  17:10
Power/exhaust emission problem warm engine
A great shame you are not nearer to Koblenz, Oliver. As Victor mentions, I am lucky to have a good Bosch guy near to me who, in fact, worked many years ago in a formula 1 team near to Manchester. He knows I'm really fussy and so do his mechanics. Having said that, they know what to do and do it well. It is easy to stab around in the dark with your RV8 replacing this and that but never actually hitting at the cause of your problem. In your case I would, first of all, get them to investigate your electrics thoroughly first and only then go at the fuel supply. If they get stuck, I would be more that willing to supply my Bosch guy's telephone number so that they can coordinate the diagnosis.
Peter Garton
31/08/2012 @  21:03
Power/exhaust emission problem warm engine
Since my dealer has checked the fuel supply serval times and it works fine, he will investigate in the ignition system on Monday, as he told me right now. If this doesn't lead to any success, I am very pleased for you offer to coordinate the diagnosis which your local Bosch service guys, Peter. It would be a great deal. Thanks for that in advance.
Best regards
Oliver Libuda
31/08/2012 @  23:12
Power/exhaust emission problem warm engine
Just before you call on the cavalry check the hoses and the joint face of the plenum to the manifold for air leaks Ė a weak mixture is either not enough fuel or too much air. But you have more than one problem; the cooling fan shouldnít run as soon as the ignition is switched on so there is a wiring fault and Iím suspicious that the new coolant temperature sensor didnít fit, is it the correct sensor and is it sending the correct signal to the ECU.

Iíll give up now and leave it to Bosch but itís an interesting problem so please report back once a solution is found.
Geoff King
01/09/2012 @  00:36
Power/exhaust emission problem warm engine
For sure we will also check for air leaks, but I will also be 100% sure, that ignition settings are adjusted as they should and that it is working correctly.
Concerning the coolant temperature sensor. I ordered it at Brown and Gammons, has part nbr. ETC8496 as already mentioned and I expected, that B&G should know the applicable parts and sell them. Do you have another part number for me, Geoff?
Oliver Libuda
01/09/2012 @  02:07
Power/exhaust emission problem warm engine
Very interesting regarding the temp. sensor from B&G. ETC8496 also fits the Landrover Discovery and there are several suppliers who also market this part including Lucas. The assembly threads do differ. The part you mention is superceded by ETC8496A which is for the RV8. I can't understand why the thread did not match up. Since I'm fairly convinced that your old part was not defective, do you still have it??
Peter Garton
01/09/2012 @  02:55
Power/exhaust emission problem warm engine
The old temperature sensor was refitted and since then the fan starts running when engine is warm again, not immediately after switching on the ignition. But very interesting to hear, that the assembly threads do differ. I guess this will also be the reason why the fan starts running, due to wrong signal.
Oliver Libuda
01/09/2012 @  04:58
Power/exhaust emission problem warm engine
The correct part number is ETC8496. If there is an ĎAí at the end of the part number it means it is an alternative part, i.e. not from the original manufacturer but an equivalent. All of these should fit but the genuine part is much more expensive than the alternatives.
Lucas SNB802
Intermotor 55128
Facet 73200
Lucas 73355A
Lucas 8TT
Lucas SNB802
Webcon WTS163
Jaguar EAC3927
Delco 213-2787
Champion CCS35 or

ETC8496 also fit the Land Rover Discovery, Range Rover and any other car that uses the Rover V8 engine with hot wire fuel injection, including the RV8 of course. The RV8 engine is not unique or special.

I have found another case of the cooling fan starting with the ignition on Ė it was believed the fault to be either the coolant or the fuel temperature sensors but unfortunately the eventual solution to the problem was not stated.

I have also found a reference to a sticker found on the packaging of a temperature sensor part number ETC8496, the sticker was Ė Peter will be interested to know - Bosch part number 0 280 130 107-000. I have no idea if this is the correct part or not.
Geoff King
01/09/2012 @  05:27
Power/exhaust emission problem warm engine
Geoff's words of wisdom really explain how careful one has to be regarding the correct part for the car. I also saw this list and became nervous when your garage had to fit an adapter which would alter the depth of the sensor. I'm very relieved that that part of your problem is now solved. Take a look at my new RV8 workshop note just added to the bulletin board no. 370 which could help your cooling when you've solved the main problem with the engine.
Peter Garton
01/09/2012 @  14:13
Power/exhaust emission problem warm engine
Since I have currently no access to my car, because of standing in the garage and I'm on a business travel next week, I will get back to you end of next week with all teh "news" occured during the week.
Until then, thanks again for the many tips.
Oliver Libuda
01/09/2012 @  22:57
Power/exhaust emission problem warm engine
Problem is solved. My RV8 is running fine again. Reason for the problem was a non correct working Mass Air Flow Sensor. When air filter was demounted, everything was fine. After mounting the air filter again, the exhaust emission values were terrible. So he found the reason.
The "phenomenon" of the non fitting coolent temperatur sensor is also solved. It seems a my dealer was that confused and also be cheesed of not finding the failure that he by mistake mixed the temperature sensor and the thermostatic switch.
Again thanks to you all. Now I am happy again and fortunately the weather is fine this weekend, so that I could enjoy driving a wonderful car :-)

Oliver Libuda
08/09/2012 @  14:23
Power/exhaust emission problem warm engine
Thank goodness it is now all ok. I haven't slept for several nights worrying about your problem so when you are anywhere near Koblenz we can have a wine together. It would be good, on a more serious vein, if you could put this info, into a RV8 workshop note. If you need help with the text formulation I shall only be glad to help, Oliver!!
Peter Garton
08/09/2012 @  18:53
Power/exhaust emission problem warm engine
Dear Peter,
I will try to pre-formulate a work shop note and send it to you for finalization.
Thanks for the invitation to a glass of wine in or near Koblenz.
On the other hand I would like to invite you and of course all the others to our next MG Bayern Event 2013. We organize this meeting every year somewhere in Bavaria. Next date would be July 12 to July 14 in 2013. The meeting is organized by the MG Stammtisch Niederbayern. It's always a nice weekend with round about 30 MGs (MGA, MGB, MGF, MGTC, MGTD and this year also 2 MG RV8). When I have more information about the meeting for next year, I will open a separate post
Oliver Libuda
11/09/2012 @  07:38
Advanced Search
Search for all messages for
Last 2 days
Last 7 days
Last 14 days
All Messages
Search by key word
Search by topic
V8 RV8
Spares Events
General Online auction
Include archived messages in search
When making a posting
do note the system automatically signs off your posting with your name

You are welcome to post a message
or response
It could be a technical query or clarification, a maintenance or spares tip, a report of good service from a V8 specialist, or news of an event of interest to fellow V8 enthusiasts. As we welcome new members, this service is provided on a "free and open to all" basis and is not restricted by password access.

Spares adverts
Any spares or other items advertised for sale on the V8BB will be removed and posted on the V8 Spares webpage on the V8 website.

V8 Bulletin Board aims
to attract good quality postings in terms of content subject matter and accuracy. It is not a chat box so any "grumping or flaring" or other undesirable postings will be moderated at the sole discretion of the V8 Webmaster and V8 Chairman. Periodically the postings are archived to keep the list of postings to a manageable length. Please disclose your name and email address when preparing your posting.

V8 Register - MG Car Club
Neither the MG Car Club, the V8 Register or its officers and committee members can accept legal responsibility for any of the statements contained in any posting or postings made on this bulletin board. Any material considered to be undesirable in terms of its nature, content or implication will be moderated as promptly as is reasonably possible. Should any party feel the content or claims in any posting may cause them actual or potential damage, please contact the V8 Webmaster promptly so appropriate action may be taken.

V8 Webmaster