I have a 2000 Limited (5.7L)... if its sits for a few hours (or over night) it takes 15 seconds of cranking to start. If I turn her off and run in a store and back out in 10 minutes she starts right up. I also notice that from a stop sign I can take my foot off the gas and it will slowly climb to 45mph while idling at 1300rpms!!!(800rpm with my foot on the brake). No codes, changed the cap and rotor, fuel filter and cleaned the intake and IAB. I put new plugs in her 6 months ago (gapped to .60, but I read that there is a TSP to gap them to .35 but cant find it) and replaced the fuel pump 12 months ago. Any siggestions?

 

Welcome to the forum, have you checked for vacuum leaks?

 

Thanks for the welcome. Yes, I checked for vacuum leaks. Funny thing is that this morning she started right up (but she still idles high once I take my foot off the brake). The last 5 mornings its been a 15 second attempt or a second or third turn of the key. Can too much fluid in the tranny cause the higher idle (all my vehicles since I was a kid have been manual trannies till the Tahoe so I am a little out of my knowledge base on automatics)

 

It only revs high after you release your brakes? You might have a leaking master cylinder. Listen for a leak by it within your engine compartment and where the rod from your brake pedal enters it.

Good luck and keep us posted!

 

what kind of power brake booster do you have the vacume or the hydroboost ? the first works off vacume and the second off power steering pump press.

 

crap, no idea on the brake booster will have to look.

Last night she was hard to start (again...she sat for 2 1/2 hours and it took 15-20seconds to fire up). I got home and decided to clean the IAB again and make sure that I put the air intake tube back on correctly over the TB. This morning she fired right up, but, driving down the road she would climb to 60 mph on her own. I stopped at a light and had to stand on the brakes as she was idleing at 1500rpms, I stuck her in neutral and the rpm's climbed to 3300!! Light changed to green and dropped back into gear and she was fine the rest of the drive to work (28 miles).... I dont get it. I checked the throttle cable again last night and there was no binding at all.

 

Have you pulled the computer codes yet? Just wondering if you have a sensor going out. I think I read some where low fuel pressure could cause it too.

 

Pulled the codes... no codes at all...clean (which killed me cause it would have at least pointed me in a direction other then throw money at her). I am going to pull the IAB out and clean her tonight if I get home early enough. I hate working on cars in the dark.

 

Wish you had more on the booster type good luck

 

I have a vac line from the booster heading to the intake area....