In gear idle dropped

[junkpile]

update, on my idle drop when put in gear. I have had a little time to start going thru this car. Timing is correct, no distributor issues (for either one I have put in), I have installed a new fuel filter (much needed) and replaced my new coil for one that was known to be good, also changed the gasket below the carb. The car starts right up (even cold, not bad for 440 with a 484/284 cam) it will idle fine at 1000 rpm and you can rev it to 3000 smoothly or hammer it and it will run fine. As soon as it goes in gear (get a load) the RPMs drop to 300 and it wants to quit. It has not quit running but it is too drastic a drop. the car has idled for years with this set up at 850-900 rpm. I can not find a vacuum leak (that does not mean I do not have one) I hear a whistling sound when in gear that i do not hear in park or nuetral. I am starting to get frustrated, I have a Edelbrock 750 performer carb, I really do not want to buy another one. but i need to be pointed in the right direction so I can figure the next steps i have to make to fix this issue. Like I stated early on, this 440 was running fine it just dropped RPMs when stopping for a light on the was home from a cruise night.

 

[pedal2themetal]

HI,
your idle is too fast.. like I said earlier 650 to 750 rpm's at idle..At 850-900 your almost out of the idle circuit so the mixture screws are going to do almost nothing.. and the timing well be way off for what it should be... I've had a 516/543 lift cam in my 466 (BBF) and it idled 650-700 rpm's and ran fine... If you can't get the idle down to a respectable number you must have a vacuum leak somewhere.

good luck take care be safe
tim

 

[toolmanmike]

Your cable slipped in the bracket. Just guessing Go back to the basics and never overlook the obvious!

 

[junkpile]

O.K. my setup for this car may seem out of wack but with the 484/284 cam my best street idle in gear is from 850-900 rpm. I have driven it set this way since i put the 440 in it back in November of 2000. The car is happy there, runs great, and it drove from GA to upstate NY several times with this set up. I am just trying to figure out why, with no warning the RPMs at idle in gear are now drop to 350. no changes were made to the car. I am still checking for a vacuum leak, but if there is a component that could have failed causing this problem I will change it, if i can figure out what it may be. I am running a 2800 stall 11" converter with a 727 trans that was rebuilt completely 4 years ago.

I dont know what cable may have slipped in the bracket, please clarify.

 

[Rusty knuckles]

First post nails where I'd look. I had a similar issue this summer. Running autocross, finished the run and car wouldn't idle in gear for anything. If I picked up rpms it was ok. Drove home ok. Messed around and adjusted the idle mixture screws and bam she starts running decent again. Thought that was odd. Drove it and it got a little worse again. Finally in checking closer, I found the vacuum booster check valve had ever so slightly dislodged. Pushed that back in and then had to undo the tuning I'd done.

Usually the problems are pretty simple.

 

[junkpile]

I believe it is something simple, just cant find it. my power brakes operate off an electric vacuum pump so no motor connection there. I checked the lines from the distributor advance to the carb (tight no leaks, checked that with a vacuum pump and guage), same for the PVC. I still have the vacuum tree on the back of the intake, capped off the power booster line and have the small vacuum line that operates the headlight s on a 69 charger. I can try to test that system but a leak there does not seem likely. The whistle i get surges with he cam when running at such a low RPM but you done hear anything in park, so i wonder if that noise is from something else.

 

[Geoff 2]

- Post #21 says 'timing is correct'. What is the timing at idle?
- The idle speed in park/neutral sounds about right for that cam in a 440.
- The cam lobes may be wiping which would explain the large rpm drop going into gear.
- Remove the carb top. Unlike brand H, you will not need gaskets if you are careful. Check that n/seats are sealing, floats are not leaking [ fuel logged ], & f/level correct: 7/16".
- whistle at idle. It can happen with any carb, is not a vac leak & not a problem. It occurs when the air speed/throttle opening is 'just right'; like blowing across an empty Coke bottle. It may come & go.

 

[1967coronet]

I have had 1 new napa pcv valve that would whistle . Damn thing took awhile to locate. No hose cracks ect. Just a fd up valve.
toolmanmike was referring to your throttle cable and the clamp that holds it in place.
Your question on plugging the vacuum advance off .... Now without trying to refight the Ported/ non Ported war.
Yes you can plug / cap the carb vacuum port and reset your idle and timing and see if it stays as set.
Not sure what your firecore distributor has for a timing advance limit plate. You may need to use a dial back timing light if available and check total timing and what rpm it's coming ( all in ) .
You will want that number under 40 jmho.
Good advice back up the thread , as posted I also would increase initial once you find your total mechanical #.
Also like posted check that cable and blow out the idle circuit. Eddy carb... just for the heck of it, pull the pistons and step rods/springs make sure all is clean and in tact. ( that little cap screw on top of the pistons) easy to drop, just back it off enough to rotate the cap out of the way.
Good luck .

 

[junkpile]

Geoff 2

Timing at idle is 12 degrees with 36 all in at 2800-3000 rpm. This thing has run great with this timing for years. never had this Idle drop out in gear before. The distrubutor (both that i have) have check out fine, with advance working. They even worked in a friends car as they are supposed to. I will pull out the metering rods an springs to make sure that is clear. the floats were at the correct 7/16" when installed but i can check them again. Like I said previously my RPM at idel in gear was at 850-900 and the car was happy there, now as soon as its dropped in gear it goes to 350 and it does not like it, it has only stalled out once but you still need to brake rev it to move it. then it runs fine till you stop.

 

[Rusty knuckles]

Get a vacuum guage and check how many inches it's pulling both idling in neutral and in gear and report back

 

[junkpile]

Know in park its 9" vacuum, i will get back to you with in gear.

 

[pedal2themetal]

Hi,
Wow 9" of vacuum at idle is way low I think..

good luck take care be safe
tim

 

[Rusty knuckles]

Yeah 9" is super low. You have a vacuum leak somewhere.

 

[pedal2themetal]

HI,
I think I'd run a compression check on it making sure it's not a internal problem with the low vacuum.. could also be valves..
Put a vacuum gauge on it and see what it says you can learn a lot with a vacuum gauge here's a link explaining on how to read one for symptoms of a problem.

Quick Tech: How to Read a Vacuum Gauge to Pinpoint Engine Problems

A vacuum gauge is an invaluable resource for tracking down engine issues. The key is understanding what your gauge is trying to tell you. We’ve put together this quick-guide to …

www.onallcylinders.com

good luck take care be safe
tim

 

[Gettyupgo]

have you checked the vaccum at the transmission, a vaccum leak can happen anywhere get out the soap suds and start squirting

 

[Geoff 2]

The 727 trans does not use vacuum....

 

[junkpile]

I really appreciate all the advise and help, thank you guys.

I am still stuck though. I would like to know if anyone else has had this stalling when in gear issue. This was a sudden thing, happened when driving home from a cruise night at a traffic light it would just not idle in gear. dropped to below 300 rpm, I could brake rev it and then drive off to go home but this issue is driving me crazy and its been months. I know some have commented about my Idle RPMs but this car has run flawlessly with my set up for years so i do not see that as an issue. I will list below all that has been look at and timing and idle rpm that has worked for years. Please point me in the direction of possible fixes short of a teardown. its a 69 charger, its no show car, I love driving it just to have time to myself on the open road, it has been driven from Atlanta GA to Upstate NY several times without issue several time with current set up so I know that is not and issue but something has failed and i can be the only one that has had this happen.

440 .030 over, 484/284 cam, Edelbrock 750 performer carb, 727 with 2800 stall converter. timing 12 degree base all in at 36 degrees at 2800-3000 rpm
carter fuel pump. Idle in park is set at 1100 rpm and in gear at idle its between 850-900 rpm ( the car has been happy here for years and will keep the headlight lit bright at night with this rpm) this setup has never given me a problem

timing is still set correctly, cam only provides 11" vacuum at idle in park, only vacuum accessories are the headlight doors and vacuum advance on distributor. Fuel pressure is between 5 and 6 psi (needle on gauge is bouncing, since i just put in in to check the psi). no kinked or rotted fuel lines, fuel filter is new. I can not locate any vacuum leak, changed the base gasket on the carb with no change to the problem.

Only changes before the problem started, added new orange control box from Mancini racing and a new hotter accell coil for a hotter spark (i did change this back to the stock coil with no change to the problem)

I was a little low on trans fluid the day this happened but I am running a pan that holds two extra quarts of fluid so I know there was enough in the trans to work, it was topped off after the car got home, no change to issue (trans leaking from dipstick tube seal, have a new lockable tube that needs to be installed to solve the leaking issue), motor Idles now at 1000 in park and in gear it is extremely rough and at around 300 and it boarders on stalling.

I have someone coming over to do a compression check in the next week or so. I want to eliminate an engine issue, when running there is no signs of a problem thru the exhaust although it is a little richer than usual by the smell behind the car, changing the idle mixture has no effect on this at all.

I dont know if i wiped a cam lobe, but I need to try anything easy first. I am looking to purchase an eddy AVS2 carb at 800cfh if the carb is the issue.

Anyone with a similer problem please tell me what you did to solve it, i need to try simple options or the car will end up sitting, I'm afraid that if it sits past Feburary I will have to place it on stands and cover it for permanent storage.

 

[DanielSlocum]

have you checked the operation of the metering rods and pistons? they should move up and down easily when pushed against the springs. also if you remove the little covers when the engine is idling the pistons should be pulled down by vacuum. if not,then you likely have a vacuum leak somewhere. another possibility is dirt plugging one or more air bleeds in the top of the carburetor. i am suspicious of your carburetor;perhaps it needs a rebuild?

 

[66 Sat]

Mate this has been going on for months and lots of suggestions have been made - you need to write them all down and tick them off one by one.
Have you got another carb you can swap in temporarily to see if that's the issue?
You said your fuel filter was very dirty before this issue occurred. Maybe some dirt got through it somehow and is in the carb? Have you done as suggested in Post 5 way back in August and blown out the idle circuit?

 

[Geoff 2]

This could be so many things.....
Could be a wiped lobe. Unlikely to be the carb unless it has water in it [ using E fuel? ].
Initial timing is waaaaaaaaaaaaaay too low for optimum idle quality, vacuum & tip in response. See below.
Since the problem started when you changed the ECU & coil, try replacing them. I hear that the orange ECUs are problematic.