98 Disco Fuel Issue

[deeb]

i recently picked up a 98 disco 4.0L.

it hadnt been run for some time before i got it due to a suspected oil pump, which thanks to joey i easily took care of.

now, the truck is starting up relatively easily and idling right around 1200rpm. however, i cant the raise the idle. i step on the accelerator, nothing. ive also tried manually opening up the throttle body, nothing.

like i said, the truck sat for some time so im planning on starting with the fuel filter. however, it gets enough fuel to adequately idle.

im confused

anyone have any ideas?

thanks for helping the new guy
chad

 

[joey]

Sounds like the butterfly may be stuck in the intake.

 

[greg409]

By the time I write this Deeb probably already unscrewed the clamp on the throttlebody flex.

Since it's now open he could operate the linkage to see if the throttle plate opens.

(He did say he tried the linkage but was he looking @ the plate?)

the only thing behind the plate are the intake horns.

luck,greg

 

[deeb]

By the time I write this Deeb probably already unscrewed the clamp on the throttlebody flex.

Since it's now open he could operate the linkage to see if the throttle plate opens.

(He did say he tried the linkage but was he looking @ the plate?)

the only thing behind the plate are the intake horns.

luck,greg

so this afternoon ill get that flex off and look inside the TB...joey, when you referred to the butterfly were you talking about what greg called the throttle plate?

so if i work the linkage and see that this plate IS in opening and closing...what next?


thanks

 

[joey]

Yes throttle plate... I have always called it the butterfly.

If it is not opening, then clean it... if it is opening, then you have a something clogged up. if you were not getting enough fuel and the butterfly opens, then it would bog down from too much air and not enough fuel.

 

[greg409]

i'm too lazy right now to look it up, but would a faulty throttle position sensor (tps) cause the mixture to lean as the butterfly opens?

I've always been tempted to take mine apart & clean it, but I'm too scared

Deeb, if you get more detailed in symptoms it might help us with tips to check'

such as, when it's idling & you manually blip the throttle does it ever "pop" thru the intake?

does it try to rev & die? does it keep idling like you're not even there?

The idle should be 700-800 rpm as I recall

If @ 1200, you may have a dirty/faulty stepper motor or a vacuum leak somewhere.

luck,greg

 

[deeb]

well, i'll be taking the intake apart this afternoon to see what sort of condition the butterfly is in and if i can get it to move with the linkage/accerator.

as far as symptoms...it idles very smoothly, just high. when i blip the throttle the truck does nothing, just keeps on idling like im not even there.

vaccuum leak is very probable, there are a number of shabby looking hoses. those will all get replaced as soon as i figure out this throttle issue.

thanks for your help guys, i'll report back after i get the throttle apart.
chad

 

[Disco Mike]

If you want to set up your idle properly, and assuming the t/body and IAC are clean, then you need to find a mechanic that can calibrate your IAC to the ECU that actually controls your idle.