Replaced heater matrix and now running rough

[Dan_Storm 0]

Ok, I'm after some big help here.....

 

I have just finished replacing the heater matrix, I've got most of the dash and switches back in place so thought I would try starting up to make sure there were no leaks and all was running well....it isn't :(

 

It starts fine, then the revs drop to the point where it sometimes cuts out. I re-checked all the connections and retraced my steps but couldn't find anything obvious. I checked everything under the bonnet, re-seated the MAF connector and a few other plugs, checked the HT leads were secure, checked relays were secure etc.

 

Still no joy....I let the car warm up for a few mins, but it didn't seem to make much difference. The car seems to run ok when revving or holding revs - i.e. it is not miss firing but doesn't sound 100%.

 

I noticed it may be running a bit lean. I put a fault scanner on and it came back with "Idle Stabilisation adaptation limit exceeded".

 

So, have I forgot anything obvious? I labelled all connectors meticulously when disconnecting and I'm sure I got it all connected back as it was. All dash switches are working as normal. Could it be I have disturbed something when moving the looms? I re-soldered a few connections when I had the dash out and I added a fuse for the headlight dimmer (as per the how-to). I was fiddling around near the ECU to undo the nut on the other side of the dash, I checked and all seems normal.

 

Anyone have any ideas? :help:

[Supercharged 2]

Dan, that code usually means air leak - have a good look through all the vac pipes etc...

[Dan_Storm 0]

Thanks Supercharged, I'll give the vac hoses a good check over. I initially assumed it was something I had dislodged, but I'm now starting to think it may be a coincidence that something else has decided to play up.

 

I'm going to collect my spare MAF and ISV from my folks to try eliminating those too.

[andy 0]

I'm going to collect my spare MAF and ISV from my folks to try eliminating those too.

Definately the way forward.

[Roger Blassberg 0]

Did you disconnect the ECU ? Or the battery? If so, settings will have been lost and will need to be re-learnt.

 

Best wishes

 

RB

[Dan_Storm 0]

Did you disconnect the ECU ? Or the battery? If so, settings will have been lost and will need to be re-learnt.

 

Roger, I did disconnect the battery. When I've disconnected the battery in the past it has always run fine after re-starting. I thought the re-learning thing was just to optimize the adaption values and would assume the car would run ok without? Maybe worth a try though. Cheers.

[Dan_Storm 0]

Well I tried my replacement MFA and ISV, and still the engine stalled and didn't idle well. I checked all vac pipes but didn't find any leaks. I gave most connectors a quick clean and tightened vac hoses. I went for a drive and it was perfect, got back and gave it a rev on the drive and it cut out. The old MAF and ISV are suspect - I replaced them years ago when I had problems...but I was hoping it would help diagnose.

 

So I swapped back to the original ISV and MAF, started and it cut out straight away. I started again and it idled fine for about 5 mins. I ran out of time so I will do a bit more testing tomorrow.

 

Anyone know if any vac pipes run inside the cabin? Just wondering if I may have knocked one while removing the dash.

 

Cheers

[Dan_Storm 0]

I think its fixed :D

 

I gave the ISV and the connected hoses a clean out, cleaned a few earthing points and all seems to be back to normal. I guess it was nothing to do with the matrix change after all and was just a co-incidence - in the way only a Corrado can do :)

[sixpotter 0]

Mine ran up ok too though now just stinks of antifreeze burning where it soaked everything. Nothing else went wrong other than some grazed knuckles. Should I have put a fuse in behind the headlight switch then?

 

Glad you got it sorted too.

[Dan_Storm 0]

Sixpotter,

 

I installed the fuse for the headlight switch light as per CrazyDaves post here. It doesn't need the dash out, but I did it while the dash was out as the wires where a bit more accessible.

 

Unfortunately I am blowing fuse number 3 when I have the headlights on and then open a door :confused4: I haven't had a chance to try troubleshooting. Has anyone else seen the same problem? Seems that fuse3 controls the dash, interior lights & number plate light.

 

Other than that the engine is running great. I did 400 odd miles over the bank holiday weekend and it didn't miss a beat. The water and oil temps seem to be lower too :)