Cold starting problems
 

It currently takes about 3 to 4 attempts to start the car when cold, any idea what to check or where to start?

It has new plugs and a new lambda.

It also seems pretty rich on idle, (2% co with CAT installed)

Cheers

Dave

Its a 93WRX by the way

New plugs? Hopefully the right ones.
Running rich? The lambda may be at fault.

It may just be that the cold is getting to it but it does seem strange it's happening after the two changes above :wonder:

Crank sensor?

Yeah it was doing it before the plugs and Lambda change, another Lambda has been tested as well, also it does it with and without a CAT.

What can i check with the crank sensor ?

Anyone got any ideas?

sounds like coolant temp sensor, its on the water crossover pipe ,below the inlet manifold,,near the turbo,,,,there are 2 fittings in there i think . bit of a bugger to get at .

coolant temp sensor maybe but this would throw a cel and cause the fans to come on from cold normally if it had completly failed.

The plot thickens, today it was not running well at all, ok if lightly driven but if i applied half throttle to start accelerating it would start back firing and bucking, feels like when the knock sensor was dodgy and it was activating limp mode. I will check the ecu codes at lunch and see if anything is thrown up.

Dave

Connected the Black connectors and turned on the ignition and a constant falshing CEL so no error codes :(

Anyone got any suggestions for me?

I had cold starting problems. No codes. Changed the CTS not a problem since.

Well i got some ebay replacements coming to try, a coil pack, a fuel filter and a crank sensor!

i had exactly the same problem on my94 changed coil packs, and plugs with no joy. turned out to be low compression in one of the cylinders (piston ring), do a compression test just to rule it out only takes an hour then atleast its rulled out.

If your mixture's too rich then logically that means you're not getting enough air (t'other side of the same coin really) so air filter would normally be the first thing to check or replace.The poor cold starting would then most likely be due to the plugs getting fouled, which is par for the course with a rich mixture.

OK i had more problems on Friday, the misfire under load was getting worse and I couldn't start it when i left work, so on Saturday i came back and tried to start it but still no joy! It was turning over fine but not firing.

Got the nice RAC man out and he diagnosed it in about 10 minutes! I had a spark but no fuel, so he walloped the tank and hey presto it started, he said he had seen this beofre with intank pumps, my fuel pump was not working very well thus could not deliver enough fuel to the engine! So i fitted the high pressure fuel pump i had sitting around at home and now its running great!!

I dont know if this will help the emissions problem? but i will find out today as its in for MOT again!

Dave :)

Car is still a bit hard to start and was spluttering a bit when cold, so CTS ordered!

But with the high flow fuel pump fitted its now going very well, the tubular headers have moved the power band up a bit, but it feels very quick through the gears now!

Dave :)

Had the cold start problem on my 1994 wrx changed the CTS and starts first time all the time and i fitted it about 6 weeks ago. Hope its that for you as a cheap fix for a change.
Neil

Well i think it seems to have fixed my cold start problem but the car if still not right!

i think its still too rich at idle and so i dont get any pops and bangs when letting off. The only real change is the tubular manifold.

Also when i leave work, and only when i leave work, about 5:30 i get alot of missing until it is a bit warmer!

getting frustrated now!

Dave :(

Maybe oxygen sensor?