Definitely IAC Valve?

[LeeMajors]

2000 3.4 Limited. 215k mi. Starts then dies basically immediately unless I give it a little nudge of gas. No issues after it is running. No codes whatsoever.

Last year I yanked/cleaned IAC with similar symptoms. No issues with performance once started. Idle is even, acceleration is normal. No other issues than a difficult crank when warm.

I've read a bunch of threads and can't really come to any other conclusion. I just want to make sure I haven't missed anything.

Anyway, I'm thinking of just replacing this time (because I don't want to revisit in 20k) but I'd like feedback on any other possible causes?

Also, I'm probably going aftermarket - I know everyone here has a boner for OEM (as do I) but 300$ for a valve seems nuts when Rockauto has a highly rated one at 120ish. I've just spent a bunch of brake booster, fan clutch, etc. and I'd like to make a good decision here.

So, what say y'all? What else could cause a quick start/die

 

[LittleCaesar]

Sounds more like the fuel pump possibly or a hanging injector, with the former if it only occurs when WARM. First of the morning OK?

Check the main ECU fuse too but it sounds fuel related.

 

[Hockeyjock]

Fuel problems and ECU are all possibilities, but my vote is still with the IAC. They are known to cause issues just like yours and cleaning it previously resolved the same issue.

 

[baja1]

remove the coil in place and rotate the armature to see if it rotates freely.

 

[gamefreakgc]

I tried a cheap re-manufactured unit and it was terrible, idles at 1100 RPMs. Brand new aftermarket is better than reman'd for these IACs.

 

[theriddler]

I tried a cheap re-manufactured unit and it was terrible, idles at 1100 RPMs. Brand new aftermarket is better than reman'd for these IACs.

:iagree: I would lean this way as well for the source of the issue. The fuel pressure regulator popped in my head as a culprit too. If you remove the throttle body to replace the IAC valve, clean that throttle body and MAF sensor while you're at it.

Absolutely positively replace with OEM parts on whatever route you go with...good luck

 

[LeeMajors]

Thanks for the info guys! Sorry for the delay--worked 12s a bunch of days in a row.

Oddly the problem stopped and has yet to return. I'll probably take an afternoon to pull/clean everything again and see how its doing but maybe it'll just be a mystery for now.

Another thing that occurred to me is that it happened right after I filled up during a ****ing monsoon here in Charleston--water in gas?

 

[Coward]

I had the same issue. Hard to start like I had no fuel pressure to start with or something. Turned out to be the fuel pump. I say that because when the pump failed, after the repair it was never hard to start again. Later I had an intermittent high/low idle problem. Grabbed a used throttle body from the local pull apart and it fixed it. That issue was a worn shaft on the throttle body causing it to bind.

 

[LittleCaesar]

Cycle the key on and off a couple of times when it doesn’t want to fire up immediately.

 

[theriddler]

Yes it could be bad gas and yes cycle the key a few times before starting....it happened to me once. Note to self-if you ever get a gas pump that's pumping really really slow shut it off and find a different gas station. The station could be running low on fuel and its sucking all the crap from the bottom of the tank. Glad you're ok for the moment