4jg2 dying when cold

[blackmu94]

hi bout a month ago i replaced my fuel filter on my MU its 4jg2 3.1, it appeared to go smoothly, but i have noticed now in the mornings when the engine is cold and idiling the revs will slowly drop and the egine dies, im not sure if this has anything to do with me changing the filter. is there any sort of idle mixture screw on the injector pump

[fly3r]

I changed mine and it hasn't effected the idle, but on all the cold morning since i have owned it, it doesn't like being at low rpm, so all i do is wind in the idle knob thing on my dash board so the rpm sit around the 900rpm mark, till it has warmed and then set it back at normal idle...

[blackmu94]

my rpm hadnt really chanded at idle but it just drops to the point the engine stall when it warm there is no problem

[geeves]

Check the filter is tight. It sounds silly but if its slightly loose it could be sucking air but once it warms up the seal expands enough to seal properly.

[blackmu94]

ill check that this arvo

[blackmu94]

checked the fuel filter and its very tight

[geeves]

Its either an air leak somewhere around there or something unrelated

[teribul]

Hi. I have a similar problem in a '90 model Jackaroo 4JB1T 2.8 turbo. I have had the car for several years and last winter was the first time the problem occurred. It has happened a couple of times so far this winter. I don't know what the problem is but if you get stuck, using the primer pump under the bonnet seems to work, especially if you get it at the rough idle stage. No fix but it gets me mobile till I can find what the problem is without being ripped off. Good luck. Cheers.

[elysian]

I sort of had an issue like this , cold start and the it would idle at like 500 rpm (very lumpy) , ended up being the alternator, the diode pack had died.. new diode pack and it idles fine now ( even at 2'C, started and idled at 750-800ish no problem )

[teribul]

My problem ended up being with the pump. Apparently low sulphur diesel has caused the seals to harden or shrink. The problem only happened in winter because everything contracted in the cold allowing the pump to suck air, I guess it would happen in warm weather when it got bad enough. Just had the pump overhauled and all is going good. My son had the same problem with his Jack and is now trouble free after having the pump overhauled. Always seemed like a problem of sucking air but couldn't find a leak until diesel started leaking at the pump recently. My rig has done 272,000k, his 340,000k. I guess the k's mean nothing because it all has to do with when the low sulphur fuel was thrust upon us. Cheers everyone

[bozza72]

Glad you got it sorted teribul but how much did it cost for the pump seals to be fixed & overhauled???

[Back Track]

Mar 3, 2008 13:30:11 GMT 11 blackmu94 said:

hi bout a month ago i replaced my fuel filter on my MU its 4jg2 3.1, it appeared to go smoothly, but i have noticed now in the mornings when the engine is cold and idiling the revs will slowly drop and the egine dies, im not sure if this has anything to do with me changing the filter. is there any sort of idle mixture screw on the injector pump

>:(I have a 4jg2 1994 3.1D Turbo Intercooled. I have a similar problem at the moment [see my queries also with Electrical] post Total Eng Rebuild.
Having spent considerable extra dollars post Eng/R and seemingly foxed these I now have the Vehicle being still hard to start. I have noticed that the Pump does not appear to hold the pressure in the pump ie- You can push the Plunger down and there is considerable free space in the tank ie one can pump it 6-8 times to feel the pressue. Its as though the Fuel pressure is some how lost when idle..
Could it be the fuel cut Solenoid?.


Love to have it running smooth again
Geoff