I need help!!!!

[skyhighjeep]

Heyy guyss i just built a 4.6 jeep stroker and im having problems. It will not idle smoothly. This is a basic stroker with 258 crank 4.0 block and rods. i have it all in time. im running stock intake. the cam i used is the 4250h-13 comp cam. i am absolutly clueless on what it could be. Pleasee help!

[skyhighjeep]

come on guyss i need some help. it will idle a little but very erraticly it kinda starts to lope. and then shuts off. i got the timing correct on the crank to cam and the distributor. my guess is some sensor. i am hoping some one has had the same problem once.

[Cheromaniac]

Are you absolutely sure you have the distributor indexed correctly?

http://www,angelfire.com/my/fan/dist_index.html

If so, check the TPS. The voltage should sweep cleanly as you open the throttle (ignition on, engine off) from ~0.75v (closed) to ~4.35v (fully open). If there are any spikes or troughs, replace the TPS.

[skyhighjeep]

im pretty sure ill check again.

[SilverXJ]

Could be the IAC, and as Dino said, the TPS. To add to dino's TPS check, there will be 3 wires. One will be ground, one will have constant 5v and one will vary with the throttle.

Did you degree your cam in?

What RPMs does the engine idle at? If the idle RPM is steady, check your motor mounts.

If all else fails you can drill a hole in your throttle butterfly valve. I got that tip from Lee @ Hesco. I had a bit of a rough idle when hot and I drilled a 7/64" hole in the butterfly valve and it improved the idle.

To check have the engine hot. Remove what ever intake tube you have on the throttle body. With the engine running (wait for the idle to stabilize as much as possible) and butterfly valve closed place a business card over the to IAC hole (IAC intake). The engine should drop idle low, but not stall out. If it stalls drill a hole in the butterfly valve, about middle and 1/4" off the shaft. You don't have to take the throttle body off to drill the hole, coat the drill bit heavily with grease and it will collect the shavings. I also put a ball of tap on the underside of where I was going to drill the hole. Clean the crease and any shavings off and try the business card test again. Start with a 3/32" bit and move up. Don't go larger than 1/8".

[skyhighjeep]

i gott itt!!! it was the distributor indexing. thank you all for your helpp.

[Cheromaniac]

i gott itt!!! it was the distributor indexing. thank you all for your helpp.

I love happy endings.