Idle Problems, any suggestions?

[TrojanMike67]

Hey Guys,

I've been having some problems with my Edel 1406 recently. I would tune the car and it would run great for a couple days. Then after a few days I would start getting hard starts and a bad idle. I usually idle at 650rpm but am idling at about 550 during the bad times. I adjust the air/fuel ratio and the bad idle/startup problems go away.

Well yesterday I bought a new 1406 and bolted it on. I also installed a brand new fuel filter. Car started up and ran PERFECTLY. I drove it for about 20 minutes and had a perfect idle. I parked my car in the garage and came and started it up this afternoon. My bad starting problem is back again. When I did get it to start, it idled at 2000rpm. I hit the gas and it went down to 1500. Hit the gas again in about 30 secs and it went to 1000rpm. I finally hit it again and it went down to about 700rpm. I then let the car warm for about 10 minutes. I checked the choke and it is functioning properly. Drove the car for about 15 mins and had the rough idle the whole time. Car seems to do well when it is moving though (response and power.) Any ideas on where to go with this problem? I can go adjust the air/fuel again, but I have heard from many people that Edels. come pre-tuned from the factory.

Car is an almost stock 351w. Has a 1406 carb, performer intake, flamethrower coil and pertronix unit.

Thanks in advance!
Mike

 

[jikelly]

It sounds like something else might be wrong besides the carb. I wouldn't think that except the probles you discribe are kinda wierd and if it were the carb you would figure a new one would have fixed the problem. I was thinking that maybe your throttle was getting stuck but that wouldn't cause a rough idle.

Now it could be the choke setting but like you said those carbs come pretty much ready to run. Myself and others have posted information on tunning edelbrock carbs recently. You should do a search and check out what everyone had to say.

How long ago did your problem start?
Is it possible that the problem is being coused by something in the ignition? Points maybe, or a bad coil?

 

[2nd Mustang]

Possible vacuum leak somewhere affected by hot and cold of engine?????

 

[MustangMatt1966]

I have had the same dang problems with the edelbrocks, you tune them, and then the idle acts up again. The way i fixed mine is by beating the heck out of it at the track, the idle is a little off, i go and slam the engine at the track and it always seems to fix the problem other than that, i dont know what to tell ya

 

[slick761]

hey my carb does the same **** sometimes. Check ur idle mix screws. If they arent set real close to the same the carbll do that sometimes

 

[MustangMatt1966]

cool, i will try that, they possibly are off. thanks

 

[bnickel]

could be a vacuum leak, but it could be in the distributor as well. i had a very similar problem with my 351 a few years ago, it turns out the distributor bushings were worn out completely. check to see if there is any play in the distributor shaft, there should be very little, if there is movement you need to replace or rebuild the distributor.

 

[65fastback2+2]

timing, vacuum, maybe your car still has points???

 

[Ozsum67]

I agree with bnickel. It could be the timing fluctuating because of a worn ditributor.

 

[MustangMatt1966]

distributor is brand new-mallory

 

[Ozsum67]

Well vacumm leak then like others have said, or what kind of fuel pump are you running? Maybe weak at a low rpm.

 

[bnickel]

i'd still check the advance mechanism in the distributor to make sure it is operating properly and freely like it should. vaccum leak would be my next guess