96 1hdft 5speed sudden idle drop ? (1 Viewer)

[hdj8081]

Fellow mudders,

I was driving on the freeway with my hdj then am about to approach traffic idle went down and engine shut off good thing still rolling engaged in 2nd gear and run again.. but it happen again same process. Checked the vacuums appears to be fine. Hard starting until you pump gas pedal 2x. Then when you rev to 2000 rpm let go engine shuts off.. any possible leads? Thanks in advance! Appreciate any ideas.

 

[Squash]

My 95 ft hates heat, and will stumble at idle when hot sometimes. I pull the hand throttle just for some extra rpms and this definitely helps.
Also doesn't like some hot starts after highway speeds, and have found that water poured on the solenoid really helps if she doesn't want to start.
Mine was putting in 16hr days driving to and from the west coast of Canada from Ontario on the hottest days.
I was trying to swap out the solenoid, but that sucker is in there very tight, and will probably need to pull the IP.
A 24mm wrench fits the solenoid, but slips, so maybe a 23mm is possible, but I haven't found one yet.
Also connected a second hot lead to the solenoid in case the original wiring was suspect, turns out I just added an extra wire.
So,
Cold engine no issues.
Hot engine sometimes double key of ignition, but water on solenoid never fails, this does lead me to believe it is the solenoid or perhaps what may be a spill valve.
I do not have the manual for this so it's guess work. What I believe is the spill valve has some available adjustment.
Hopefully someone with knowledge grabs the torch on this one.

 

[PBcuiser]

Air getting into fuel line due to something expanding at high temps? Maybe a hose getting loose. has the issue persisted since this first incident?

 

[hdj8081]

Yea at first side street last week then back to normal then yesterday fway felt it was worse since it happened 2 consecutive times.

 

[hdj8081]

wonder if it has something to do with inj pump needs rebuild or injectors.

 

[PBcuiser]

Easiest things to check first are confirm air and fuel filters are clean, and confirm no air is getting into the fuel lines. replace fuel supply line at the back of the injection pump with clear PVC tubing and watch for small bubbles. Also some injection pumps have the ASCD (?) unit that can change idle speed i think? Maybe check into if that is functioning properly or not. My 1HZ doesnt have that so cant offer advice on that

 

[hdj8081]

Easiest things to check first are confirm air and fuel filters are clean, and confirm no air is getting into the fuel lines. replace fuel supply line at the back of the injection pump with clear PVC tubing and watch for small bubbles. Also some injection pumps have the ASCD (?) unit that can change idle speed i think? Maybe check into if that is functioning properly or not. My 1HZ doesnt have that so cant offer advice on that

Ascd i think was removed by previous owner.

 

[mudgudgeon]

Definitely spend $10 on a piece of clear pvc hose.

Temporarily replace the hose between the fuel filter assembly and the injection pump.

Watch for air bubbles in the fuel.

 

[hdj8081]

Definitely spend $10 on a piece of clear pvc hose.

Temporarily replace the hose between the fuel filter assembly and the injection pump.

Watch for air bubbles in the fuel.

If theres air bubbles, just need to prime it?

 

[mudgudgeon]

If theres air bubbles, just need to prime it?

No, if there's air bubbles, your fuel system is leaking & sucking in air

There's loads of threads about this here in the diesel tech section

 

[mudgudgeon]

^^^ edited coz auto edit sucks!

 

[Squash]

If you have no vacuum leak allowing air into the fuel, and can confirm this via a clear hose, and/or ensuring that the primer bulb is firm within a couple of pumps, then move on down the line.
Now if it takes a number of primer pumps to stiffen the resistance, then you definitely sucking air.
A truly robust fuel supply system should "never" require many pumps to stiffen up.
If you go this route, start a the injection pump to primer/filter housing ensuring no air bubbles, then primer/fuel filter towards the tank. There will be a metal pipe on the firewall under the brake booster.
My secondary solenoid wire is fired up via the IGN terminal located in the little black box on PS near the air filter.