4.9L Idle

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Feb 3, 2009 | 06:06 PM

#16

javi2001

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From: Venezuela

Thanks for your comment: Well even a totally bran new Ford IAC was installed and performs exactly same. New TPS and MAP, IAT, ECT, Sprak plugs, cables, rotor, cap also

Any more ideas???

Feb 3, 2009 | 07:12 PM

#17

optikal illushun

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From: Coal Region

well, not that seems off.

next question, has the idle screw on the throttle body been touched at any point in time? it also sounds like something isnt working in the A/C clutch to enguage a high idle.

Feb 3, 2009 | 08:44 PM

#18

javi2001

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From: Venezuela

Thanks again. Idle stop screw was verified and it is in its position. The A/C works fine. I even try using a set of 6 used inyectors/fuel press. regulator and a used/know good ECM computer and both do same, so the problem still been in the wiring or maybe the intake manifold???

I notice your signature shows a F150 93', can you tell what's the idle behaviour of your truck?

I was thinking.... I read if ECM notice the engine or trany temp is high, the ECM will increase idle to provide more fresh air for cooling and more water flow, is that right??? if so, maybe the problem is just the trany temp sensor...

Feb 3, 2009 | 09:11 PM

#19

optikal illushun

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From: Coal Region

my idle is nothing like normal. i have a 302/351 throttle body and the upper and lower intakes have been ported. the larger TB has slighly effected my idle. plus i have a different cam and that effected the idle slighly...but...

cold idle, no A/C, park - 900 rpm
warm idle, no A/C, park - 750 rpm

cold idle, A/C, park - 1,000 rpm
warm idle, A/C, park - 850 rpm

im not sure our trucks have a trans temp sensor.

Feb 4, 2009 | 08:58 AM

#20

javi2001

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From: Venezuela

Thanks for your coments. I have same crane 503905 installed, but my idle problems came form the old tired 4.9L just removed 1 month ago...

Auto trannys like E4OD, 4R100 does use a Transmision Fluid Temperature Sensor (TFT) installed in the solenoid pack. ECM use this information to correct pressure vs tranny temp.

I was considering to buy a cheap scanner to try to get readings from sensors while driving. Can recomend one? cheap? maybe used?

Feb 4, 2009 | 10:25 AM

#21

Freaksh0w

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Joined: Jan 2009

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From: East Tennessee

Have you tried just adjusting the idle screw yourself? I can't tell if you are doing this, or if someone is 'verifying' this for you. While there are a few certain ways people say to set it, like unplugging the TPS, then setting the idle down to 500 RPM, then plugging the TPS back in, I think after that, you can fine tune it just a half turn one way or the other. I bumped my idle up just a notch after I adjusted mine by those directions. It just helped me to idle better up hills in 1st gear (NP435). It didn't raise my idle, in the long run, as much as it just helped hold that idle while pulling hills in 1st without touching the accelerator.

Wow, got a little off subject, point being, maybe you could set the idle that way, then adjust it just the way you want it.

Feb 4, 2009 | 11:34 AM

#22

javi2001

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From: Venezuela

Thanks for your Help/Comments.

YES I did myself verify the stop screw, going full back and then in until the throttle plate doesn't stuck any more. Even with ALL throttle plate closed, the engine still running high idle.

Next week I'll receive a brand new Ford Injectors Set and a Variable fuel pressure regulator to continue with my engine upgrade after crane cam. A friend told me maybe the injectors are leaking fuel while Idling, maybe because sometimes smell like unburned fuel...