[andykao]

My engine has been working ok so far, changed spark plugs and DIC about 2 months ago.



I was driving and i suddenly start losing power. I stop the car to see what's going on.


It seems the engine will stall when at idle - sometimes it try to increase RPM, sometimes it just stalls instantly.


If i start the car and hit the gas pedal immediately, it revs up nicely. I i keep it around 2k RPM, it stays there, engine sounds ok, sounds normal (no nasty sounds, although the RPM sometimes fluctuates a little).


So with the car standing still, i can keep the RPM steady, however, if i put it in gear (it's a manual), and slowly raise the clutch, it will instantly die down (even if it's a 5k RPM).


MAF has been cleaned a few months ago, new air filter, new BPC valve, new serpentine belt, new fluids, the car was running absolutely fine until now.



What should i look for?

 

[CarpeCyprinidae]

as a first check I would be tempted to check the system voltage. At 2000rpm you should be seeing 14.2 to 14.6 volts. If its much lower than 12.4v it would indicate either a failing alternator or a bad electrical ground - either of which could cause the fuel pump relay or ignition coils to drop out.

Also try running it at tickover with the fuel filler cap removed, if it runs OK then it indicates an issue with the fuel tank breather system causing a vacuum.

My feeling is this is going to be electrical though, and in all probability, ignition. the higher voltage available at 2000+rpm would mask the symptoms of a failing coil pack. Does your car have a DIC ignition pack or a coil and distributor? If the latter its easy to check by spraying a fine mist of water around the coil and wires and looking for lightning, if the latter, replacement might be a required test. From memory B205R is one of the high output turbo engines with a DIC ignition cartridge

 

[andykao]

Yea, the car has a black DIC - got it new about 2 months ago. I still have the old one which worked ok, i'll try to replace it and see how it goes.


Will try to measure the voltage and see what's what...

 

[BobSaabit]

You've probably answered this in another thread... but is the DIC factory and are the plugs NGK? Also, review the plugs to see if there's anything interesting in the color/deposits on them.

The CPS can act funny when hot. Also the TB is known for funkiness when worn. The TB should throw a code but might not. I'd also replace all the small vacuum lines (4mm / 5/32 ID) to make sure you don't have a leak. There are four on a T7 and 10' of hose should easily cover what you need.

No CEL light, I assume?

 

[andykao]

the dic is the oem one and the spark plugs are NGK. there are no codes (which is strange). this indeed happened when hot outside, the car ran fine throughout the winter. will check the CPS and probably replace it. TB = Throttle Body? If yes, i cleaned it about 2 weeks ago, it was clean before, but who know.


CEL is random, sometime it kinda flashes, sometimes it's completely off - but the engine behaves the same.


I'll get the new vacuum lines on friday and change them asap.

 

[BobSaabit]

A flashing CEL is a "Catalyst Damaging Misfire". It's usually a serious DIC issue. It can also be an injector issue. Since you already replaced your DIC with a factory one, I would lean towards an injector issue causing the problem. However, swap the DIC back if the other one is still good and see if it changes.

 

[jakejm79]

I've also seen large air leaks screw with the A/F ratio so much it causes cat damaging misfires. I'd double check that there are no leaks after the MAF.

 

[andykao]

fixed it! it was a stupid thing, the air intake pipe got disconnected from the throttle body. it was just a small gap but it was sucking air though that gap.


put it back on, now it all works great!