94 with 3.0 missing at startup

Hello - I have a 94 Pickup that has the 3.0 V6 automatic that misses when it starts up. It will miss for about 10 to 30 seconds then smooths out and runs fine. It started a few months ago, since then I've replaced the plugs twice and the plug wires twice and the distributor cap and rotor button. It doesn't do it everytime and sometimes it worst then others. Any help would be appreciated and thanks in advance.
Paul

Does it smoke on cold start? Is it worse after the truck has sat for 2 hours instead of 20 minutes? Harder to start after 2 hours instead of 20 minutes? (Maybe smell gas fumes near the rear of the truck after it's sat overnight?).

It could be the cold-start injector. It can leak, bleeding into the air manifold. The result is what I described above. I happened to me once. I don't recall if it missed. But, it could miss if running rich like that, until it clears out after 20-30 seconds.

The thing I remember was hard starting and smoking, worse after the truck sat for hours instead of just a quick trip into the mall for 20-30 minutes.

Thanks for the feedback auto89,
There were two specific occasions that the truck smoked way more than normal at start-up. Both times the truck had sat for about two days. Yes, if the truck sits longer between starts it seems to miss more and a little longer, but never more than 30-40 seconds. As for hard to start or gas smell, it has never been hard to start and I really hadn’t noticed a strong gas smell. I’ll check that out later today.
So you had to replace the cold start injector? If so, how much was it?
Thanks
pwoffutt

It's about $122 at rockauto.com

I thought about it more after I replied to you and, what you call "missing," that might have been what I experienced. I would have called it rough idle for the first 20 seconds.

Again, it kind of depended on how long it sat. If only 10 minutes while I went in the local quick mart, no problem. 3-4 hours, a little problem. 8-10 hours at work, a significant hard start, rough idle, blowing smoke.

Regarding fuel smell. I've had this go out once. The pressure dampner on the end of the fuel rail go out once (underneath the air plenum, passenger side, rear of engine). And, the fuel pressure regulator go out once (near distributor cap). I definitely smelled fuel for those other two items. I don't remember if I smelled fuel with the cold-start injector. I might have smelled it when it was idling rough, smoking, smelling like it was rich.

The repair manual describes how to test it. It's on the passenger side of the air plenum. A few inches to the rear of the EGR valve.

This is for an 89 3VZE.

on-vehicle test: Disconnect the electrical connector from the cold-start injector. Measure resistance across the two contacts of the injector. Should be 2-4 ohm.

There is a test to check spray pattern and pressure leak-down. You remove the injector, jumper Fp and +B in the test box (a 1"x2" plastic box on the passenger wheel well, inside engine compartment). Turn ignition to on (but don't start engine). Connect injector to battery. Should give fine spray when connected. Not drip more than 1 drop per minute when disconnected.

I don't understand that test procedure. It uses a special connector which seems to have two leads that connect to the battery. So, I'm not clear what Fp and +B do. Or, why the ignition needs to be on. It seems to connect directly to the battery(!).

Since it involves gasoline, I probably wouldn't try it unless I really understood what's going on.