under boosting RS2....

[DamoM]

If your ur is not converted to direct ignition, do not try its ecu as the pin order is different!
I assume here your urq is original 20v RR.

Knock sensor fault is way more probable than MAP fault IMO.

Mine is actually a 10v WR from 1986 but it has a full RS2 injection and engine management system fitted, including direct ignition (I assume you mean coil per plug?).

Wouldn't a knock sensor fault show up a a stored code on the ecu?

[porkkis]

Not necessarily, no. If the ciruit is cut or short to ground, yes but otherwise not likely.

Try your urq ecu (with your rs2 chips, not urq), but I don't think it'll help.

I've been thinking of a 10v project with motronic but apparently I'm late to be a pioneer
How did the engine charasteristics change or did you have lots of other mods done at the same time?

[4WheelDrifter]

I had an intermitant fault on my cq20v. It took me ages to work it out. One minute the car would be running fine, then it would have a sudden loss of power. Then it would be ok again. Completely random. It turned out to be a faulty knock sensor.

[AAH!]

TPS ? (THROTTLE POTENTIOMETER SWITCH)

http://www.sjmautotechnik.com/trouble_shooting/20vthrot.html

and I'm sure you've looked here, some of it may be relevant:

http://www.sjmautotechnik.com/trouble_shooting/20vboost.html

[AAH!]

DamoM,

Have you had any luck sorting your low boost problem yet?

I've just from got home from a 2 hour motorway drive and I think my RS2 might have devolped the same problem as yours, although mine seems intermitant.

Full boost behaving like normal maxing at 1.9 bar, then for no apparent reason the for next few times I put my foot down max boost is down to 1bar. Then back to normal again. Occasionaly when the boost is holding back at 1bar if I let the revs get up to about 5500rpm the boost will kick in again, but not always.

Over the last week I fitted new coil packs had the injectors cleaned all seemed to be working better than ever, although I did get a boost leak through the throtle body hose as I hadn't done the clip up tight enough. Yesterday I cleaned the idle stabalisation valve and cleared all the stored fault codes on the ecu by pulling the ecu fuse.

I am wondering if it a combination of the ecu relearning the adaptive fuel mixture after the ecu's memory was cleared, combined with the slightly lower flow rates the cleaned injectors are now giving me the car is running lean, compared to when it was mapped by Mihnea resulting in detonating/pinging and the knock sensors are retarding the boost .(as per 4wheeldrifter post and here:
http://www.sjmautotechnik.com/troubl.../20vknock.html)

Could this be the case?

I will pull the blink codes tomorrow and clean the WGFV and the DV just in case.

Angus

[tekkno435]

Full boost behaving like normal maxing at 1.9 bar

If you don't mind me asking, what mods have you done to achieve this?

graham.

[AndyP]

Did the output test and all came up fine. The system pressure tested at about 1.2 bar according to the boost gauge and very slowly dropped off?

Tried running the car with the WGFV disconnected. With it disconnected the boost is only about 7 psi so I guess the ECU is controlling the boost to some extent. The fact that it is not controlling it to limp home values, that there are no codes and the ecu has been reset (the diaphragm is fine and the MAF connections have been cleaned) kind of points me to tubo failure? Have inspected the vanes on the inlet side but it all looks ok so not too sure how else to check it without removing it? There was some oil around the inlet housing and the car did burn some oil on startup at the trackday at Castle Combe - but only the once. Also, on changing gear at full chat there was some oil blow back through the filter (that's when I noticed boost was low and came in!) although this again has not recurred?

Any ideas?

You said in this ealrier post that you'd had some oil blow back through the filter, have you tried cleaning the MAF with IPA since? It maybe that the wire is covered with oil and not giving you the correct reading. Just a thought.

Andy

[DamoM]

Not necessarily, no. If the ciruit is cut or short to ground, yes but otherwise not likely.

Try your urq ecu (with your rs2 chips, not urq), but I don't think it'll help.

I've been thinking of a 10v project with motronic but apparently I'm late to be a pioneer
How did the engine charasteristics change or did you have lots of other mods done at the same time?

Yes, afraid so! All of the good engine characteristics stayed as per std UR but starting, idling, pickup, high rev power and just about anything else improved. The system really has been amazing. I did it with Quattronut (see www.quattronut.org) who are real URQ enthusiasts. It was not an easy conversion though - be warned. Have had endless other things done to my car since and the motronic has been able to adapt to it all with no problem.

[DamoM]

You said in this ealrier post that you'd had some oil blow back through the filter, have you tried cleaning the MAF with IPA since? It maybe that the wire is covered with oil and not giving you the correct reading. Just a thought.

Andy

Andy, that is a very good point, didn't think of that!

I will swap out the MAF with one from my others cars and see if it makes a difference.

[DamoM]

DamoM,

Have you had any luck sorting your low boost problem yet?

I've just from got home from a 2 hour motorway drive and I think my RS2 might have devolped the same problem as yours, although mine seems intermitant.

Full boost behaving like normal maxing at 1.9 bar, then for no apparent reason the for next few times I put my foot down max boost is down to 1bar. Then back to normal again. Occasionaly when the boost is holding back at 1bar if I let the revs get up to about 5500rpm the boost will kick in again, but not always.

Over the last week I fitted new coil packs had the injectors cleaned all seemed to be working better than ever, although I did get a boost leak through the throtle body hose as I hadn't done the clip up tight enough. Yesterday I cleaned the idle stabalisation valve and cleared all the stored fault codes on the ecu by pulling the ecu fuse.

I am wondering if it a combination of the ecu relearning the adaptive fuel mixture after the ecu's memory was cleared, combined with the slightly lower flow rates the cleaned injectors are now giving me the car is running lean, compared to when it was mapped by Mihnea resulting in detonating/pinging and the knock sensors are retarding the boost .(as per 4wheeldrifter post and here:
http://www.sjmautotechnik.com/troubl.../20vknock.html)

Could this be the case?

I will pull the blink codes tomorrow and clean the WGFV and the DV just in case.

Angus

Sounds stange. Intermittent faults like this are rare and point to an intermittent fault on a sensor. Boost leaks or turbo problems tend to be consistently bad (or get progressively worse). I would check connections to all the sensors, paying particular attention to the MAF. I am sure that the codes will show which one is to blame though.

[DamoM]

TPS ? (THROTTLE POTENTIOMETER SWITCH)

http://www.sjmautotechnik.com/trouble_shooting/20vthrot.html

and I'm sure you've looked here, some of it may be relevant:
http://www.sjmautotechnik.com/troubl.../20vboost.html

Yes, done everything on this site! It is a fantastic site though don't you think?

[AndyP]

Did you ever get this sorted?

[DamoM]

Did you ever get this sorted?

Yes, sorted finally on Friday!! After more or less pulling the engine to bits, my last resort (as previously suggested on here I might add!) was the knock sensors. I swapped them with ones off of my urq and lo and behold full boost....!

I had more or less convinced myself that it wasn't these so more fool me. When you thnk about it it makes complete sense - the ecu doesn't recognise a sensor fault but simply reacts to a (faulty) pinking. I am not sure which one was to blame so have two more on order to put onto the urq (which is in bits at the mo)

Thanks to everyone foir their help and input on this thread.

[AAH!]

Glad your boost is back!

My problem (as described above) ended up being a dodgy knock sensor as well, albeit in my case a poorly soldered wire in the connector.

[DamoM]

Ahhh! I love a happy ending!