High revving at start

pleco

pleco

Well-known member
Mar 5, 2007
75
0
Cape Town South Africa
Hello Guys and Girls.

I have a 3.9 v8i that revs extremely high at startup once the car is warm. The stepper motor then kicks in and slowly brings the revs down to normal.

I have changed: Stepper, TPS, both water temp sensors and the fuel temp sensor so far.

The flow meter works, but cannot set the CO below 4. I have tried, but cannot get the base idle to 525rpm. The butterfly is set correctly.
 
LANDROVER LUKE

LANDROVER LUKE

Well-known member
Apr 6, 2010
71
0
LOUISVILLE,KY
has the tab on the throttle linkage been bent to correct a problem incorrectly?? i've seen people bend the tab for the throttle stop to bring the idle up--this can confuse the stepper and create other issues --erratic idle
 
A

adamsoccer

Well-known member
May 21, 2006
182
0
Tallahassee/Gainesville, FL
I've got the same issues on a 95 RRC 3.9 and gone thought all the sensors like you have. I do have the excessive smell on gas. I know how to test the ohms resistance of the fuel injectors with a multimeter, but is there a way to DIY test for a leaky injector?

If an injector is leaky can you replace just the 1 or is it best go go with a rebuilt set? Anyone have any experience with these: (ebay # 270559829169). $137 shipped looks like the cheapest anywhere.

http://cgi.ebay.com/ebaymotors/89-90-91-92-93-94-95-Land-Rover-Range-Rover3-9Lhttp://cgi.ebay.com/ebaymotors/89-9...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
 
Discoinjapan

Discoinjapan

Well-known member
Feb 14, 2006
2,526
7
50
Yokosuka Japan via PA
Search for leaking injector. PT has explained it many of times!

Edit: myself, I would change them all.



adamsoccer said:
I've got the same issues on a 95 RRC 3.9 and gone thought all the sensors like you have. I do have the excessive smell on gas. I know how to test the ohms resistance of the fuel injectors with a multimeter, but is there a way to DIY test for a leaky injector?

If an injector is leaky can you replace just the 1 or is it best go go with a rebuilt set? Anyone have any experience with these: (ebay # 270559829169). $137 shipped looks like the cheapest anywhere.

http://cgi.ebay.com/ebaymotors/89-90-91-92-93-94-95-Land-Rover-Range-Rover3-9Lhttp://cgi.ebay.com/ebaymotors/89-9...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
Click to expand...
 
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A

adamsoccer

Well-known member
May 21, 2006
182
0
Tallahassee/Gainesville, FL
Think I got it,

Hook up a fuel pressure gauge and watch for a drop in pressure over 30min when the engine is turned off.

I also saw that some people pulled the rail and injectors, leaving the tops and plugs hooked up and put the ignition in the pump on position to watch for in individual leak.
 
Roving Beetle

Roving Beetle

Well-known member
Nov 11, 2007
4,823
0
Mount Desert Island, Maine
www.desertboat.com
If you're going to the effort of pulling them - just replace them/rebuild them.

If the truck has any miles on it/age (they all do now!) then they could stand to be rebuilt and tested/flow matched.

There is a good company I've used if you have the time (couple days or so) to send them out. I'll find it in my lists.... hold on. :)

EDIT: RC Engineering (very good luck with them) http://www.rceng.com/Fuel-Injector-Cleaning-P43C0.aspx?UserID=5055878&SessionID=otXNEY2h8TigOKYBzRdr

I also once used Cruzin Performance or something like that? They did very well and were a quite a few $$ cheaper. EDIT: http://www.cruzinperformance.com/fuelinj.html
 
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