Runs rough at idle?

[rsh4364]

My 85 1009 runs great at every speed but idle,I drive it about 100 miles per day,speeds up to 70 mph,runs very well 20mpg,but idles like it has a big cam in it,and blows black smoke at idle. IP or injectors,or both ? Also starts great when warm but not so good when cold.Has elect.fuel pump upgrade,spin on filter,carries 8lbs.fuel pressure into filter and to IP,also new fuel line from elect.pump to spinon filter.

 

[sandcobra164]

Sounds like the injectors need going through. The black smoke at idle is the symptom for me. Some are releasing too early causing overfueling on those cylinders and starving fuel to the others which is causing black smoke and loping at idle. You're IP is likely fine.

 

[rsh4364]

Thanks it really never did this till I ran it out of fuel a while ago.Ill start with injectors and then move on from there.

 

[rsh4364]

Sounds like the injectors need going through. The black smoke at idle is the symptom for me. Some are releasing too early causing overfueling on those cylinders and starving fuel to the others which is causing black smoke and loping at idle. You're IP is likely fine.

I replaced injectors and it still idles rough but runs even better.Then I thought I might have low compression on a few cylinders,did test(thanks richingalveston) all cylinders in 385-400 psi range.the rough idle is much more noticeable in gear not so much when in park or neutral.Clear fuel line on return line shows no bubbles.And truck will run fine even down the road at 70mph with lift pump turned off.So Im not sure if I need to replace IP,but that is next step.

 

[cucvrus]

That's because a CUCV does not have injectors. It has delivery nozzles. The injector is built into the injection pump. The metal lines carry the metered and pressurized fuel to the nozzles and deliver the fuel at the exact pressure they are designed to release the fuel at. I know there is a more advanced term and explanation for this fuel delivery system but that is in basic English. As far as being able to help you with the issue. I can't be 100% sure. I never had a CUCV that had an electric fuel pump.

 

[southdave]

My 85 1009 runs great at every speed but idle,I drive it about 100 miles per day,speeds up to 70 mph,runs very well 20mpg,but idles like it has a big cam in it,and blows black smoke at idle. IP or injectors,or both ? Also starts great when warm but not so good when cold.Has elect.fuel pump upgrade,spin on filter,carries 8lbs.fuel pressure into filter and to IP,also new fuel line from elect.pump to spinon filter.

Sound like you are good, your cold start solenoid is kicking in doing what it should. I believed that that it functions, by under fueling to increase the heat need to smooth out.HPCA: High Pressure Cold Advance; this mechanism advances the timing by about 6 degrees to compensate for the slower burning injected diesel charge until the engine warms up to around 125F.
here check this out
http://www.oliverdiesel.com/tech/howdb2pumpworks.htm

 

[southdave]

Sound like you are good, your cold start solenoid is kicking in doing what it should. I believed that that it functions, by under fueling to increase the heat need to smooth out.HPCA: High Pressure Cold Advance; this mechanism advances the timing by about 6 degrees to compensate for the slower burning injected diesel charge until the engine warms up to around 125F.
here check this out
http://www.oliverdiesel.com/tech/howdb2pumpworks.htm

AND.... Houston I have problem... let see if I can figure it out.. My gp and wing harness is wiped out (manual push button) when I bought 1028. the temp sender was replaced with gauge. see if I can just wire it to work or have to get jiggy with it..

 

[scottladdy]

Cold start issue: Glow plugs? Starter spinning fast enough? (sounds like you have gone through the likely fuel delivery issues)

Idle issue: Idle speed too low? Less likely IMO but is the air filter clean?

Not precluding the above suggestions. But always start with the basics.

Next: How old is the IP? If it is anywhere near original I'd consider replacing it just as a safety/peace of mind measure. They deteriorate due to age. IP's and injectors can also get pretty scored up if the truck was ever run on old fuel, which could adversely affect idle quality. Fuel loses lubricity as it ages. IIRC the original pieces lacked hardened internals that would tolerate low lubricity fuels. A good rebuild will have hardened parts due to low sulfur requirements in modern fuels, which generally translates into lower lubricity. These pumps use fuel as a lubricant.

Hope this helps ...

 

[rsh4364]

Cold start functions well,new GPs and checked,new starter spins good,idle speed turned up a bit,all filters new.I think its the IP even though truck runs fine with no lift pump and has no bubbles in return line.Or maybe IP timing is off.I posted a vid.of it on youtube search rsh4364 then look for 1009 rough idle.I do have a rebuildable IP core on the way to me now that I can hopefully get rebuilt.I also ordered a new 31 gal.fuel tank,sending unit and straps.This 1009 sat dormant for 8yrs. before PO purchased,then he sold to me.I ran it out of fuel and that's when rough idle developed.I think I ran some garbage thru IP,but it confuses me because truck runs so good other than at idle.Also when I put new tank in Im going to install new mech.lift pump in addition to the electric one,the electric pump has a toggle switch so I can turn off and on.

 

[southdave]

Did you read the part where the solenoid advances timing 6 degrees and reduce your bowl presure to 0?.. your fuel mods have created precombustion issues imho dial the fuel mod back a bit or disconnect the solenoid on the pump also check the glass ball at the return fuel nipple. IT is important beause it is what control the bowl presure and will contribute to a rough idle. ?

 

[southdave]

Watch video your fine truck and injection pump works as it should.. btw tighten your belts and check motor mounts... please read the link I posted. Also learn to use idle advance .. it r8und thingy mounted on the linkage. Think it in the starting procedures in the tm...

 

[rsh4364]

Did you read the part where the solenoid advances timing 6 degrees and reduce your bowl presure to 0?.. your fuel mods have created precombustion issues imho dial the fuel mod back a bit or disconnect the solenoid on the pump also check the glass ball at the return fuel nipple. IT is important beause it is what control the bowl presure and will contribute to a rough idle. ?

Thankyou for the link I was unable to access yesterday but could today.This problem happened when 1009 was completely stock,The upgrades seemed to help,but I really think IP is problem due to me running it out of fuel.And running some debris through it.It is my only means of transportation right now so I really want it to be healthy.Also the glass ball must have been removed before I purchased. it ran, started,and idled perfectly until I ran it out of fuel.And I seem to have a lot of debris in pre filter consistently.

 

[southdave]

Wow I was curt I apologize. Dealing with my own cucv **** at the moment let me know if you need help...
Dave

 

[rsh4364]

Thanks Dave, no apologies necessary,I will get this truck running right again!

 

[rsh4364]

I have searched the sight and no one had a good answer for my problem,gonna do a ip rebuild and hope that's it. oops that did not come out right,sorry guys.I have read lots of discriptions with identicle symptoms as mine but no definite fix.Someone mentioned bad cam lobe or dished lifter,but wouldn't that make it miss all time not just at idle?

 

[m1008chevy]

Did you ever get the issue resolved?

 

[rsh4364]

Did you ever get the issue resolved?

Not yet its waiting for me to quit working on the 86 1009 recently purchased.I do have bunch of new parts for her,fuel tank,lift pump,IP,radiator starter and more.Hope to have running again soon.Im pretty sure my problems were the IP and fuel system.