Very rich on cold start, cold start injector bad?

radiod

Supramania Contributor
Dec 13, 2007
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I started my car up today just to make sure it will go when I need it to this weekend to swap my exhaust around and after it fires up I notice a ton of dark smoke from the tail pipe. Then the stock water temp gauge hits just above the bottom line, the smoke stops coming out of the tail pipe and everything's happy from there on in. Started a bit slow, but no rough idle, no missing, nothing odd (sounding) at all. It's not burning oil, the smoke isn't blue and I haven't lost any oil since redoing my head. It's not burning off coolant either, and the smoke DEFINITELY doesn't smell like coolant.

My guess is that I've got some issue with my cold start injector. My questions are this....is that about the right temp for the cold start injector to be turning off? Also, would it be safe to try starting up without the cold start injector to see if it clears up the problem? I was thinking of either disconnecting just the cold start injector time switch from the thermostat housing; is that enough or would I have to disconnect the clip from the injector itself?

EDIT: Forgot to mention that it passed Aircare (smog, whatever you want to call it) with flying colors since the rebuild.
 

radiod

Supramania Contributor
Dec 13, 2007
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Is it more likely that my cold start injector is leaking and letting fuel sit in the intake manifold then? I'd expect if any of the other injectors were leaking that it would run funny, wouldn't it?
 

jetjock

creepy-ass cracka
Jul 11, 2005
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Redacted per Title 18 USC Section 798
More likely than it staying on electrically, that's for sure, but unlikely to be the cause of your problem.

Eyeball it with the fuel pump jumpered on by either removing it from the manifold or looking through the TB. You might also want to do a rest pressure decay check...
 

radiod

Supramania Contributor
Dec 13, 2007
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Even if it's the temperature bringing out the problem, it's still a problem. If something's not working right I want to fix it ;) I'm going to see if I can do a fuel pressure decay test when I do my exhaust switch at the shop tomorrow.