rough idle when warm

mpieper · 08-14-2008, 09:15 PM

I have a 95 12valve. Runs grest when cold then develops a rough idle and sounds like it might be missing. 180 K

Recent injectors, new fuel filter and air filter.

Any ideas?

Joe G. · 08-15-2008, 09:32 AM

You may have the idle set too low. It should be 850 with the trans in gear (if auto) and the AC on. Look here for fuel system info: Joe G's fuel system writeup

You should fill out your signature with truck info so we can answer questions better.

__________________
KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

chevy791979 · 08-15-2008, 09:34 AM

Calling All 12v Guys

GOING THROUGH THE SAME STUFF MAN.

__________________
95 12v one ton 5 spd. custom 5x14 injectors.66mm hx50 timing 17.5. 4k gv springs, marine head gasket, 12 mm studs 191 dv's. single 7 in stack.
421/ 893 ON OLD TUNE UP. guages of corse. POWER PARTS ENGINEERING DD clutch. FOR SALE.

I.B. Cummin · 08-15-2008, 09:42 AM

is 65 or 7 too low with ac on?

__________________
(looking 4 injectors) '98 12v 2wd 5sp man:#100 plate ff,4k gsk w/hd springs,aem HD,4"exh, ring-heat grid-cat-muff all gone, kdp tabed, etc. and an 04.5 HO qdcb(stock)

Joe G. · 08-15-2008, 09:44 AM

If you mean 650 or 700, the answer is yes.

__________________
KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

I.B. Cummin · 08-15-2008, 09:48 AM

with ac on and sitting still im below 700, i guess its time for a lil adjust. do u recommend 850 or 900 or 1000?

__________________
(looking 4 injectors) '98 12v 2wd 5sp man:#100 plate ff,4k gsk w/hd springs,aem HD,4"exh, ring-heat grid-cat-muff all gone, kdp tabed, etc. and an 04.5 HO qdcb(stock)

Joe G. · 08-15-2008, 09:50 AM

850 works well for me, but I have an auto. Maybe some guys with manuals will chime in if 850 is too much or too little for a manual.

__________________
KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

mpieper · 08-15-2008, 05:13 PM

Mine in a manual, what is the correct idle for it ? It now idles at about 650.

Thanks

Joe G. · 08-15-2008, 07:52 PM

650 is way too low.

__________________
KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

mpieper · 08-16-2008, 06:08 PM

Yesterday the truck idle was very smooth, not sure if it was just the cool air temp all day (max 63 degrees) or what.

We will see what happens when it gets hot again.
What effect might temp have on the way the truck idles?

__________________
95 12 valve, stage 1 pump modification, 4 " exhaust,
5 speed

08-14-2008, 09:15 PM	#1 (permalink)
mpieper Newbie Join Date: Jul 2008 Posts: 14 mpieper's Truck Pics	rough idle when warm I have a 95 12valve. Runs grest when cold then develops a rough idle and sounds like it might be missing. 180 K Recent injectors, new fuel filter and air filter. Any ideas?

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08-15-2008, 09:32 AM	#2 (permalink)
Joe G. Diesel Freak Join Date: Apr 2007 Location: Eureka, CA Posts: 827 Joe G.'s Truck Pics	You may have the idle set too low. It should be 850 with the trans in gear (if auto) and the AC on. Look here for fuel system info: Joe G's fuel system writeup You should fill out your signature with truck info so we can answer questions better. __________________ KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

08-15-2008, 09:34 AM	#3 (permalink)
chevy791979 Cummins Enthusiast Join Date: Mar 2008 Posts: 288 chevy791979's Truck Pics	Calling All 12v Guys GOING THROUGH THE SAME STUFF MAN. __________________ 95 12v one ton 5 spd. custom 5x14 injectors.66mm hx50 timing 17.5. 4k gv springs, marine head gasket, 12 mm studs 191 dv's. single 7 in stack. 421/ 893 ON OLD TUNE UP. guages of corse. POWER PARTS ENGINEERING DD clutch. FOR SALE.

08-15-2008, 09:42 AM	#4 (permalink)
I.B. Cummin Cummins Fan Join Date: Aug 2008 Location: Nor-Cal Posts: 93 I.B. Cummin's Truck Pics	is 65 or 7 too low with ac on? __________________ (looking 4 injectors) '98 12v 2wd 5sp man:#100 plate ff,4k gsk w/hd springs,aem HD,4"exh, ring-heat grid-cat-muff all gone, kdp tabed, etc. and an 04.5 HO qdcb(stock)

08-15-2008, 09:44 AM	#5 (permalink)
Joe G. Diesel Freak Join Date: Apr 2007 Location: Eureka, CA Posts: 827 Joe G.'s Truck Pics	If you mean 650 or 700, the answer is yes. __________________ KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

08-15-2008, 09:48 AM	#6 (permalink)
I.B. Cummin Cummins Fan Join Date: Aug 2008 Location: Nor-Cal Posts: 93 I.B. Cummin's Truck Pics	with ac on and sitting still im below 700, i guess its time for a lil adjust. do u recommend 850 or 900 or 1000? __________________ (looking 4 injectors) '98 12v 2wd 5sp man:#100 plate ff,4k gsk w/hd springs,aem HD,4"exh, ring-heat grid-cat-muff all gone, kdp tabed, etc. and an 04.5 HO qdcb(stock)

08-15-2008, 09:50 AM	#7 (permalink)
Joe G. Diesel Freak Join Date: Apr 2007 Location: Eureka, CA Posts: 827 Joe G.'s Truck Pics	850 works well for me, but I have an auto. Maybe some guys with manuals will chime in if 850 is too much or too little for a manual. __________________ KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

08-15-2008, 05:13 PM	#8 (permalink)
mpieper Newbie Join Date: Jul 2008 Posts: 14 mpieper's Truck Pics	Mine in a manual, what is the correct idle for it ? It now idles at about 650. Thanks

08-15-2008, 07:52 PM	#9 (permalink)
Joe G. Diesel Freak Join Date: Apr 2007 Location: Eureka, CA Posts: 827 Joe G.'s Truck Pics	650 is way too low. __________________ KDP tab fix info and fuel system article jgeorge1@suddenlink.net '95 2500 CC auto 4X4,3.54,Combo EGT/boost guage,PacBrake,TST #5,370 injectors,DTT TC/VB, Cummins chrome kit.

08-16-2008, 06:08 PM	#10 (permalink)
mpieper Newbie Join Date: Jul 2008 Posts: 14 mpieper's Truck Pics	Yesterday the truck idle was very smooth, not sure if it was just the cool air temp all day (max 63 degrees) or what. We will see what happens when it gets hot again. What effect might temp have on the way the truck idles? __________________ 95 12 valve, stage 1 pump modification, 4 " exhaust, 5 speed