smudge67999 · Jan 18, 2014

hi folks i have a 3.9v8 1997. whats happening is wen staionary you hit the gas pedal revs go up to 3/4 thousand rpm. but then for it to drop back down to tick over takes its time and its a little un steady. i have put new plugs in and taken the plenium inlet off washed and cleaned all the throttle body out all breathers there is a black electrical unit which bolts on by 2 flat head screws and when the throttle is opened it turns the spring mechanisum inside this unit.not sure what it does. but any help would be good.oh checked all vaccume hoses.

listerdiesel · Jan 18, 2014

That sounds like the throttle position indicator, it tells the ECU what the throttle position is at all times.

They aren't cheap, so try and get one you can swap over to test, also get someone to check if the throttle is in fact coming back to idle mechanically.

Peter

smudge67999 · Jan 18, 2014

listerdiesel said:
That sounds like the throttle position indicator, it tells the ECU what the throttle position is at all times.

They aren't cheap, so try and get one you can swap over to test, also get someone to check if the throttle is in fact coming back to idle mechanically.

Peter

hi peter were is this throttle position indicator is it a electrical component.regards paul

listerdiesel · Jan 19, 2014

smudge67999 said:
hi peter were is this throttle position indicator is it a electrical component.regards paul

Yes.

Peter

discool · Jan 20, 2014

Simple things first, sticking throttle cable or pedal, then idle control valve not returning to home position, haven't a clue why the throttle position sensor would be slow to show the throttle is closed.

Also if I can "feel the tick over" then I pour injector cleaner in the fuel and it goes away, but that's only about once a year.

MattMatt · Jan 21, 2014

I had this exact same problem but I run my 3.9 on carbs which had been rebuilt. It took me ages but I eventually rebuilt the distributor where I found the advance retard springs had been bent so weren't working correctly. I also replaced the amplifier on the side opf the dizzy and these two things sorted everything out. I'm not saying this is the specific reason for your problem but it might be worth checking with a strobe light that AR is working ok.

Do you get any misfiring?

smudge67999

Active Member

listerdiesel

Well-Known Member

smudge67999

Active Member

listerdiesel

Well-Known Member

discool

Well-Known Member

Attachments

MattMatt

Active Member

Similar threads