truck not running well.. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Prerunner1982 · 08-21-2004, 03:40 PM

ok... i had planned on working on the exhaust today to finally fix the collectors.. i needed to run some errands this morning, when i got in the truck and took off it couldnt get out of its own way. In park, it runs smooth and fine, in drive it stumbles and cant get up to speed. when i try to give it gas it just stumbles worse. I got it back home and cleaned up the carb a bit and tried it again. same result, on the way home it finally opened up a bit but it is still stubbling. The plugs and wires seem fine, i am going to go clean the engine off later as it does have an oil leak. Any ideas? I have only had the new Q-jet on there for a year. time for rebuild already???? any ideas??

ocbaud · 08-21-2004, 03:51 PM

fuel filter??

corn · 08-21-2004, 04:16 PM

HEI with a weak battery?

Does it have a miss or does it just plain run bad?

Prerunner1982 · 08-21-2004, 04:43 PM

to me it sounded like a miss, it increased with the speed of the engine, but as i am sure everyone here has noticed i dont know all that much... so i am not 100% sure what it is (or i would have fixed it,

)

the fuel filter is only a few months old, and from my experience with fuel filters, its usually the other way around, runs bad at idle, but better at speed.

my battery has been having problems lately, gauge shows volts at or below 13, Alt is new.. i was going to change my ground coming off the battery and see if that helped the low voltage problem. This has been going on for some time, but the stubbling problem just started today. Could the weak battery have messed up the HEI? now that i think about it, it sounds like maybe something in my distributor may be messed up. advance weights or something... will check that.. any other ideas?

corn · 08-21-2004, 06:26 PM

An HEI dist needs full voltage to work properly.

A real easy way to find out what cylinder is missing on a vehicle is to take a 12volt test light & clip the ground on the air cleaner stud. Then with the engine at idle push the test light probe through the plugwire boot to the post on the HEI cap.

If the plug & wire are good you will notice a change in the way the engine runs. Do that on every plug wire & if there is no change, that cylinder is dead. What you are basicly doing is grounding out the cylinder. I usually retest any dead cylinder just to make sure you get an arc to jump to the testlight.

It works just as well as an expensive trip to the shop...corn

cliffsta · 08-21-2004, 06:38 PM

yeah id say be darn sure plugs/plug wires are good, and your volts do sound low, supposed to be getting 14.4; my battery is on its last leg and is only givin me between 11-13 volts.

Prerunner1982 · 08-21-2004, 07:47 PM

ok thanks for the help, i decided to check the distributor, low and behold the back to hold downs werent even holding the cap down. I recently took a short trip through some deep mud and figured that some dirty water got up in there. i take the cap off and it was quite dirty and corroded. i cleaned it all up and put the cap back on right and it runs awesome now. thanks for the help guys..

cliffsta · 08-22-2004, 07:26 PM

you're welcome man, glad your up and running again

Prerunner1982 · 08-23-2004, 11:03 AM

DOH!! only thought i was up and running again...

MylilBowTie · 08-23-2004, 11:46 AM

Still the same?

Prerunner1982 · 08-23-2004, 12:41 PM

It was still the same problem sunday when i left for work, when i came home it would run, but really crappy at idle, even in park ,and like crap in drive but i could break the 35 mph barrier,

but i could still tell it was stumbbling. I just went to get my paycheck and go to the bank.. still running like crap to work.. i leave work and it ran fine the rest of the way home..

cliffsta · 08-23-2004, 06:19 PM

did you check the distributor rotor? all you said was you checked the cap. if water got down the the rotor and those 3 wires then spring for a new cap and rotor. AND in my opinion (as i just did this not a month ago) when you replace one peice of the spark system, you might as well change it all to remove the hassle of peice by peice. IE cap, rotor, plugs, and plug wires.

MylilBowTie · 08-24-2004, 01:44 AM

maybe coil module?

Prerunner1982 · 08-24-2004, 10:40 AM

i havent touched it yet and now it runs fine again. I have a feeling this may take awhile to track down....

Grim Reaper · 08-24-2004, 05:05 PM

fuel filter. The filter is plugged. The pump can make enough to keep up with idle demaond but unce you start using some real fuel it cant keep the float bowl full.

I don't care that you changed it a couple months ago change it again

I have had this happen on both my K5's. Took them wheeling . The sediment at the bottom of the tank breaks loose and clogs the filter. On the one truck I had 2 weeks in a row had to change filter every other day. Finaly got it out of it's system after about 2 months. When it sits over night some of the sedimate will settle to the bottom of the filer and it will run ok for a little bit till it gets stired up again.

Prerunner1982 · 08-24-2004, 05:32 PM

grim, now that you mention it, that might be a good idea... will have to try it.. it is still running well today.. so we will see...........

dark-star · 08-24-2004, 07:21 PM

another thing you can check is the wires to the ignition module in the bottom of the dist, assuming you have a model with vacuum advance, those wires over time get brittle and when they only partially break you can get a bad run or even a no run condition especially when you step on the gas, it sounds more ignition related to me BUT with todays crappy gas fuel filters can easily get plugged up as well leaving you with an o.k. idle but no power as well good luck, had an ign. issue that wound up being the module wire so as they say experience pooled is a dangerous thing

jw

dark-star · 08-24-2004, 07:25 PM

also does it chug real bad as there is a tendency for your float to sink and cause an overrun or even just a piece of crap in the needle/seat can cause excess fuel flow, if it is idling crappy tap on the front top of the carb and see if it knocks it loose, also you can rev the motor up and then manually slam the choke flap shut, usually one or 2 tries will dislodge any small crap plugging the jets. jw

08-21-2004, 03:40 PM	#1
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	truck not running well.. ok... i had planned on working on the exhaust today to finally fix the collectors.. i needed to run some errands this morning, when i got in the truck and took off it couldnt get out of its own way. In park, it runs smooth and fine, in drive it stumbles and cant get up to speed. when i try to give it gas it just stumbles worse. I got it back home and cleaned up the carb a bit and tried it again. same result, on the way home it finally opened up a bit but it is still stubbling. The plugs and wires seem fine, i am going to go clean the engine off later as it does have an oil leak. Any ideas? I have only had the new Q-jet on there for a year. time for rebuild already???? any ideas?? __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

08-21-2004, 04:43 PM	#4
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	to me it sounded like a miss, it increased with the speed of the engine, but as i am sure everyone here has noticed i dont know all that much... so i am not 100% sure what it is (or i would have fixed it, ) the fuel filter is only a few months old, and from my experience with fuel filters, its usually the other way around, runs bad at idle, but better at speed. my battery has been having problems lately, gauge shows volts at or below 13, Alt is new.. i was going to change my ground coming off the battery and see if that helped the low voltage problem. This has been going on for some time, but the stubbling problem just started today. Could the weak battery have messed up the HEI? now that i think about it, it sounds like maybe something in my distributor may be messed up. advance weights or something... will check that.. any other ideas? Last edited by Prerunner1982; 08-21-2004 at 04:48 PM.

08-21-2004, 06:38 PM	#6
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	yeah id say be darn sure plugs/plug wires are good, and your volts do sound low, supposed to be getting 14.4; my battery is on its last leg and is only givin me between 11-13 volts. __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

08-22-2004, 07:26 PM	#8
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	you're welcome man, glad your up and running again __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

08-23-2004, 11:46 AM	#10
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	Still the same? __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

08-21-2004, 03:51 PM	#2
ocbaud Garage Queen Material Join Date: Oct 2002 Location: USA Posts: 4,129	fuel filter??

08-21-2004, 04:16 PM	#3
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	HEI with a weak battery? Does it have a miss or does it just plain run bad?

08-21-2004, 06:26 PM	#5
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	An HEI dist needs full voltage to work properly. A real easy way to find out what cylinder is missing on a vehicle is to take a 12volt test light & clip the ground on the air cleaner stud. Then with the engine at idle push the test light probe through the plugwire boot to the post on the HEI cap. If the plug & wire are good you will notice a change in the way the engine runs. Do that on every plug wire & if there is no change, that cylinder is dead. What you are basicly doing is grounding out the cylinder. I usually retest any dead cylinder just to make sure you get an arc to jump to the testlight. It works just as well as an expensive trip to the shop...corn

08-21-2004, 07:47 PM	#7
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	ok thanks for the help, i decided to check the distributor, low and behold the back to hold downs werent even holding the cap down. I recently took a short trip through some deep mud and figured that some dirty water got up in there. i take the cap off and it was quite dirty and corroded. i cleaned it all up and put the cap back on right and it runs awesome now. thanks for the help guys..

08-23-2004, 11:03 AM	#9
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	DOH!! only thought i was up and running again...

08-23-2004, 12:41 PM	#11
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	It was still the same problem sunday when i left for work, when i came home it would run, but really crappy at idle, even in park ,and like crap in drive but i could break the 35 mph barrier, but i could still tell it was stumbbling. I just went to get my paycheck and go to the bank.. still running like crap to work.. i leave work and it ran fine the rest of the way home..

08-23-2004, 06:19 PM	#12
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	did you check the distributor rotor? all you said was you checked the cap. if water got down the the rotor and those 3 wires then spring for a new cap and rotor. AND in my opinion (as i just did this not a month ago) when you replace one peice of the spark system, you might as well change it all to remove the hassle of peice by peice. IE cap, rotor, plugs, and plug wires. __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

08-24-2004, 01:44 AM	#13
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	maybe coil module? __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

08-24-2004, 10:40 AM	#14
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	i havent touched it yet and now it runs fine again. I have a feeling this may take awhile to track down....

08-24-2004, 05:05 PM	#15
Grim Reaper Registered User Join Date: Jul 2001 Location: Atlanta GA Posts: 1,704	fuel filter. The filter is plugged. The pump can make enough to keep up with idle demaond but unce you start using some real fuel it cant keep the float bowl full. I don't care that you changed it a couple months ago change it again I have had this happen on both my K5's. Took them wheeling . The sediment at the bottom of the tank breaks loose and clogs the filter. On the one truck I had 2 weeks in a row had to change filter every other day. Finaly got it out of it's system after about 2 months. When it sits over night some of the sedimate will settle to the bottom of the filer and it will run ok for a little bit till it gets stired up again. __________________ Grim-Reaper 70 Pontiac LeMans Sport Convertible, worlds longest resto in progress Looking for 71-72 2wd Blazer or Jimmy Project



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08-24-2004, 05:32 PM	#16
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	grim, now that you mention it, that might be a good idea... will have to try it.. it is still running well today.. so we will see...........

08-24-2004, 07:21 PM	#17
dark-star Registered User Join Date: Jun 2004 Location: fargo N.D. Posts: 80	crudddy runnning another thing you can check is the wires to the ignition module in the bottom of the dist, assuming you have a model with vacuum advance, those wires over time get brittle and when they only partially break you can get a bad run or even a no run condition especially when you step on the gas, it sounds more ignition related to me BUT with todays crappy gas fuel filters can easily get plugged up as well leaving you with an o.k. idle but no power as well good luck, had an ign. issue that wound up being the module wire so as they say experience pooled is a dangerous thing jw

08-24-2004, 07:25 PM	#18
dark-star Registered User Join Date: Jun 2004 Location: fargo N.D. Posts: 80	Oh also does it chug real bad as there is a tendency for your float to sink and cause an overrun or even just a piece of crap in the needle/seat can cause excess fuel flow, if it is idling crappy tap on the front top of the carb and see if it knocks it loose, also you can rev the motor up and then manually slam the choke flap shut, usually one or 2 tries will dislodge any small crap plugging the jets. jw

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