Idle problem - Moparts Forums

Register Log In Moparts Forums Unlawfl's Race & Engine Tech Idle problem

Print Thread

Idle problem #1074427 09/13/11 03:40 PM 09/13/11 03:40 PM
Joined: May 2003 Posts: 902 Gilbert, AZ A Aspen7695 OP super stock
Aspen7695 OP super stock A Joined: May 2003 Posts: 902 Gilbert, AZ	When I start the car it idles in neutral(1500 rpm). As soon as I put in drive it looses rpm and dies. I can keep it running if I keep feathering the gas pedal. It use to idle at 1200 in gear. It is a 360 with a 850 Thermoquad and a 904 with 8" converter. I've been running this carb for over a year with no problems. While at the track we tried 2 other TQuads that are know to be good. I had the same idle problem with each of them. I checked for vacuum leaks and did not find any. I'm open to all sugggestions on how to fix this problem. Thanks, Raul

Re: Idle problem [Re: Aspen7695] #1074428 09/13/11 03:52 PM 09/13/11 03:52 PM
Joined: Jul 2004 Posts: 3,816 Arlington, Texas B bobby66 master
bobby66 master B Joined: Jul 2004 Posts: 3,816 Arlington, Texas	Pop off the distributor cap and make sure the advance mechanism is working properly. Also check timing, plugs, wires etc. You sure you dont have bad gas in there?

Re: Idle problem [Re: bobby66] #1074429 09/13/11 04:02 PM 09/13/11 04:02 PM
Joined: May 2003 Posts: 902 Gilbert, AZ A Aspen7695 OP super stock
Aspen7695 OP super stock A Joined: May 2003 Posts: 902 Gilbert, AZ	The advance is all in by 1500 rpm. Timing is at 36*. Wires and plugs look good. It does not miss when I make a run. I just got the fuel and as stated above it does not miss during the run. Raul

Re: Idle problem [Re: Aspen7695] #1074430 09/13/11 04:32 PM 09/13/11 04:32 PM
Joined: Jul 2010 Posts: 1,491 Oologah, Oklahoma Big Squeeze pro stock
Big Squeeze pro stock Joined: Jul 2010 Posts: 1,491 Oologah, Oklahoma	Quote: The advance is all in by 1500 rpm. Timing is at 36*........... Raul That sounds like at least part of the problem.....Timing CAN NOT move from when idling in neutral to idling in gear.....If the weights are moving around and you put it in gear, the timing backs up because the RPM is lower now......To check it, just lock it out and see what it does...... If that fixes it, you need stiffer springs in the dizzy and probably more initial timing.... If you can't handle the truth, you're living a lie.......

Re: Idle problem [Re: Aspen7695] #1074431 09/13/11 04:33 PM 09/13/11 04:33 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: The advance is all in by 1500 rpm. Timing is at 36*. Wires and plugs look good. It does not miss when I make a run. I just got the fuel and as stated above it does not miss during the run. Raul You advance would be dropping off as soon as you put it in gear... fatten up the idle screws and see if it holds... still could be the advance... you could make it come in just a little higher RPM

Re: Idle problem [Re: Big Squeeze] #1074432 09/13/11 04:56 PM 09/13/11 04:56 PM
Joined: Oct 2005 Posts: 164 Savannah, GA mopar400 member
mopar400 member Joined: Oct 2005 Posts: 164 Savannah, GA	Quote: Quote: The advance is all in by 1500 rpm. Timing is at 36*........... Raul That sounds like at least part of the problem.....Timing CAN NOT move from when idling in neutral to idling in gear.....If the weights are moving around and you put it in gear, the timing backs up because the RPM is lower now......To check it, just lock it out and see what it does...... If that fixes it, you need stiffer springs in the dizzy and probably more initial timing.... I just went through this very same issue. My 1200 RPM timing was at 18 deg. When I put it in gear it would go down to around 12 deg. and wanted to stall. I have an MSD pro billet. I went to the thick black spacer to limit the centrifigual advance. It now idles the best it ever has. Kevin 1965 Fury II 1970 Challenger 440, 509 cam, 11:1 w/ 452 iron heads, 6.99 1/8, 11.29@ 120mph 1/4 (1999 Magnolia Drag strip track champion) 1992 Jeep XJ Crawler

Re: Idle problem [Re: Aspen7695] #1074433 09/13/11 08:58 PM 09/13/11 08:58 PM
Joined: Dec 2009 Posts: 20,647 in a cattle trailer down by th... G Guitar Jones Paddle faster! I hear banjo music!
Guitar Jones Paddle faster! I hear banjo music! G Joined: Dec 2009 Posts: 20,647 in a cattle trailer down by th...	The others are right, you can't have full advance in at 1500 which is the out of gear idle speed and then drop it to 1200 in gear and expect it to idle. My question is though why is it idling at 1500 to begin with? My .700 lift roller cam small block with a tunnel ram will idle at 1100 all day. Unless this is a huge roller in a small cube small block Super Stock application, something is wrong. There are many tricks to help the TQ idle circuit, I'm no TQ guru but I've modified a few and they worked good. I can tell you that many of those carbs have idle restrictors in them, turning the mixture screws out only goes so far. Also if you open the throttle blades with the idle screw too far (1500! yikes) you are already into the transition circuit and not on the idle circuit. You may need to drill the primary throttle blades and idle restrictors to get the air and fuel flow necessary without the large throttle blade opening. "Follow me the wise man said, but he walked behind" '92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.

Re: Idle problem [Re: Guitar Jones] #1074434 09/13/11 11:36 PM 09/13/11 11:36 PM
Joined: May 2003 Posts: 902 Gilbert, AZ A Aspen7695 OP super stock
Aspen7695 OP super stock A Joined: May 2003 Posts: 902 Gilbert, AZ	Thanks for the suggestions. I have he advance come in at 1500 as a suggestion of my engine builder. This is a stock eliminator motor. It only has a .465 lift, but over 300* duration and it will not idle smoothly below 1250. I checked the distributor and it is OK. There is still only one spring on it. It is a Mallory Unilite. I run 20* initial and have 16* of advance in the distributor. I have the idle screws backed out three turns. I know the internals of the carb have been modified for racing by my close friend that holds the national record with a Mopar that has a similar TQuad on it. I have been running the car like this for over a year and I never had this problem until last week. I has performed flawlessly up until this time. Could I have a problem with the tranny or converter? Raul

Re: Idle problem [Re: Aspen7695] #1074435 09/14/11 10:35 AM 09/14/11 10:35 AM
Joined: Oct 2005 Posts: 164 Savannah, GA mopar400 member
mopar400 member Joined: Oct 2005 Posts: 164 Savannah, GA	Quote: Thanks for the suggestions. I have he advance come in at 1500 as a suggestion of my engine builder. This is a stock eliminator motor. It only has a .465 lift, but over 300* duration and it will not idle smoothly below 1250. I checked the distributor and it is OK. There is still only one spring on it. It is a Mallory Unilite. I run 20* initial and have 16* of advance in the distributor. I have the idle screws backed out three turns. I know the internals of the carb have been modified for racing by my close friend that holds the national record with a Mopar that has a similar TQuad on it. I have been running the car like this for over a year and I never had this problem until last week. I has performed flawlessly up until this time. Could I have a problem with the tranny or converter? Raul My engine has the .509" cam with 292 duration. It never use to idle smooth below 1000 rpm. Now it idles great in gear 700-800 RPM. I swore it was my carb. It took awhile to release the timing was dropping out and causing the stalling. Kevin 1965 Fury II 1970 Challenger 440, 509 cam, 11:1 w/ 452 iron heads, 6.99 1/8, 11.29@ 120mph 1/4 (1999 Magnolia Drag strip track champion) 1992 Jeep XJ Crawler

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1