Hard starting and occasional idle issue?

[Toms94z71]

Ok for the past week or so my truck has been giving me a hard time starting, I have to put my foot on the gas pedal just slightly to start it. Doesn't do it all the time either. I put new plugs in it yesterday and new cap and rotor on it today, my contacts in my cap were pretty burnt but it had been on the truck about 60k miles. It will start now with out me having my foot on the gas most of the time since I put the cap and rotor on it, but it will still stumble some initially some times but not all the time. It has all the power it ever had going down the, and it would stall occasionally when i had the ac on and turning at the same time. I pulled the air cleaner off, and looked at the injectors spraying, they have and excellent pattern and pulse to them, Fuel pressure regulator is fairly new and from looking at the spray on the injectors I don't believe fuel pressure is a problem. I'm leaning toward a bad egr valve, I replaced it about 60k miles ago, and a few months ago it was throwing the code for it on and off, but in the past month and a half it hasn't come on, I'm thinking the valve is stuck slightly open, I do get a little surge at idle but not much maybe 50-100 rpm, it's just the hard starting that is really bothering me now. I'm down to it either being the egr valve, the distributor itself, or my actual computer. the Distributor only has about 70k on it which is what the motor has. I'm really just wondering if anyone has had hard starting on here do to the egr. I read it is possible for it to cause hard starting if it is stuck open. Last time my egr went bad it would surge like crazy around 1500 rpm, it's not doing it this time, but I know it may be because it has failed in a different way. Thanks for any help or advice.

 

[SAATR]

EGR is possible, as well as a sticky/dirty IAC valve or a small vacuum leak. Pull the EGR and test it with a vacuum pump for leaks and proper pintle movement. If it's dirty, clean it up and see if that improves the situation. Same goes for the IAC, just pull it and clean it to see if it corrects the problem. Vacuum leaks are pretty self explanatory, and for your symptoms it would have to be a very small one. Good luck!

 

[Toms94z71]

I sprayed all around searching for vacuum leaks tonight and couldn't find one, I cleaned the passage way for the IAC today, every other time I've had an IAC itself go bad on my truck or my car it threw a code right away almost, but I know it won't for a dirty passage. I'm going to just pull the egr valve tomorrow, i hope it is related to that.

 

[MOBS]

My 94 yukon did this exact same thing, checked and replaced non working iac and still had to give it gas to start, the rubber hose from tbi to pcv valve was split right at the tbi. wrapped it in electrical tape to check it and boom, started right up cold or hot.

 

[nate]

My 94 yukon did this exact same thing, checked and replaced non working iac and still had to give it gas to start, the rubber hose from tbi to pcv valve was split right at the tbi. wrapped it in electrical tape to check it and boom, started right up cold or hot.

This fix will work or you can get a replacement for the pcv to tbi tube for about $4. I just replace mine because of cracked boot.

 

[Toms94z71]

well it turned out the plunger on the end of my IAC had about screwed all the way out of my IAC, Put a new IAC in problem solved, new threw a code I geuss since the electric part of the IAC was good still.