very strange occasional engine behaviour

[r5b18ft]

Hello guys..

My car is acting very weird occasionally. It normally runs very well but sometimes it starts stuttering when on low gears and the idle goes really rough. It feels like suddenly it is running really rich.

I've found out that switching off the car and removing the battery terminal and leave it still for a minute or two resolves the problem. Must be something with the electronics right ??

My first thoughts where the MAF sensor but I've recently changed that with a known good one (at least thats what I was told from the guy I've bought it off). Bdw car is running higher then standard boost (1bar) but I've got a richmod..

Any ideas ?

[Van]

This reminds me of the problem I recently had. The workshop changed the distributor and a temperature sender and it was fixed.

[r5b18ft]

This reminds me of the problem I recently had. The workshop changed the distributor and a temperature sender and it was fixed.

both recently changed...

[chriskay]

I guess that engine just doesn't like being in a Renault (and who could blame it)

[r5b18ft]

I guess that engine just doesn't like being in a Renault (and who could blame it)

well, it shouldn't.. it should know its roots better

[chriskay]

I guess that engine just doesn't like being in a Renault (and who could blame it)

well, it shouldn't.. it should know its roots better

Fair comment.

[r5b18ft]

.... any ideas ?!?

[Robou]

If you are still using the EZ210K leave the battery terminal off for a longer period, say at least 20 minutes. This will fully reset the ECU. There will be a moment the event reoccurs. Note the conditions. It will probably be at high load and going off throttle. If so, check the recirculation valve and the valve in the air inlet of the idle valve. In combination with some knocking and a (more or less) modded ECU the event as you describe it may happen.

[r5b18ft]

If you are still using the EZ210K leave the battery terminal off for a longer period, say at least 20 minutes. This will fully reset the ECU. There will be a moment the event reoccurs. Note the conditions. It will probably be at high load and going off throttle. If so, check the recirculation valve and the valve in the air inlet of the idle valve. In combination with some knocking and a (more or less) modded ECU the event as you describe it may happen.

My EZ210K is a richmod.. does this still apply ?

By 'valve in the air inlet of the idle valve' do you mean the sort of 'blow off valve' before the idle control valve ?

ohhh and thanks for the help

[Robou]

Yes, yes, and don't mention.

[r5b18ft]

what do I exactly check ? isn't that sealed ?

and by 'recirculation valve' do you mean the dump valve ? mine has been removed and an atmospheric one has been placed instead. Obviously I've also used u bung on the other side.

[Robou]

Sorry, but you altered a good design, probably for the sake of some noise under the hood, and who knows what else has been changed. It is hard now to come to the right conclusions, it is like playing a game of blind chess and I'm not particularly good at that. From here it is guessing, and I would rather not.

[r5b18ft]

Actually i had to do so. the rubber intake was all cracked and literally fell apart so i had to manufacture one out of aluminum. i managed to 're-do' all the other connections but i thought the dump valve wouldn't have made a difference

[chriskay]

If I remember correctly, replacing the recirculation valve with one for the Audi TT is recommended if you have the Richmod. As Robou says, fitting a dump valve instead can cause all sorts of problems.

[r5b18ft]

but isn't a recirculation valve the same as a dump valve, but instead of dumping the air to atmosphere dumping it back into the intake ?

does that small quantity of air make that much difference ?!

and how does this explain removing the battery to reset all electronics and problem is suddenly gone ?

[chriskay]

does that small quantity of air make that much difference ?!

Well, yes, if the air has already been measured by the air mass meter.

[bkf_uk]

An atmospheric dump valve will cause this condition. The ecu has already "read" the quantity of air that has passed the MAF. the dumping of this air to atmosphere causes the ecu to judge the fueling wrong and a very rich followed by a sudden lean fuel air ratio will be detected. with this condtion the ecu will go into a form of "limp" mode until reset. Basicaly change the atmospheric "dump" valve for a recirculating one. I did a how to some time ago describing which valve is best to fit.