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View Full Version : Car isn't running right... Please help!



84hurst
08-04-2009, 12:29 AM
So here's the deal. My Olds has been running like crap lately. I recently took it out of storage after sitting for almost 2 years. It feels like its running on only 5 cylinders, usually only under a light load but occasionally even at idle in park. Under WOT it runs perfect. So far I ran Seafoam through the carb and gas tank (fresh tank of premium too). I pulled all the plugs, cleaned them and regapped them, pulled the cap to try and find any carbon traces and found none. Still the problem persists. I've looked into the carb while it is running and it is getting plenty of fuel from the accelerator pump. It is getting spark at every cylinder. What I originally thought was that the carb was gummed up and it wasn't getting enough fuel but by the looks of it, it is getting enough. Tomorrow though I want to try and run gas from a conatiner directly to the carb to find out if the inline fuel filter is plugged, but I don't think so and maybe try and swap in a different carb to see if it gets better. Motor specs: '73 Rocket 350, bored .030 over, comp cam, ported/polished/shaved heads (10.5:1), Performer RPM intake, Performer RPM 750 cfm carb with electric choke and factory HEI ignition. Anyone else have any ideas??

SSDude
08-04-2009, 05:17 AM
Vacuum leak? Cap off any vacuum lines and see if it improves at idle.

DR.FORD
08-04-2009, 07:02 AM
Holley carb? Power valve may be deteriorated, or air bleeds plugged.
If you need help PM me.
Jim

jbiscuit
08-04-2009, 12:26 PM
plugged/dirty idle circuits?

84hurst
08-04-2009, 12:55 PM
Holley carb? Power valve may be deteriorated, or air bleeds plugged.
If you need help PM me.
Jim

Edelbrock 750 w/ electric choke.

84hurst
08-04-2009, 12:56 PM
plugged/dirty idle circuits?

Do you know where I would find those? That would be great if it was just a crappy connection.

Prince Valiant
08-04-2009, 01:44 PM
The first thing is like SS said...check for vacuum leaks always. Everything is connected, tightened, no craked hoses, etc...also check for vacuum leaks around the manifold/head. That is almost always the first thing to check.

It is probably your idle circuit...the resulting lack of fuel making it through is giving you the idle/part-throttle/cruise driveability problems, but doesn't factor much in WOT settings (The idle circuit still puts through pretty much the same amount of fuel at idle as it does for WOT...it just becomes a smaller percentage of the fuel for each setting). It's very easy for the circuit to get gunked up sitting for long periods. BUT, the fact that it's not at it's worst idling does give me a little pause.

While running the car on the road, put it under a progressive load...like speed up w/o downshifting. Don't use enough throttle to open the secondaries, but enought to go to the power enriching circuit on the primaries. It might still run a little rough, but it should improve considerably. If it does...almost certainly the idle circuit is the culprit. If not, it's probably something else.

There could then be a problem with the idle air bleeds (where air is drawn in), or perhaps there is gunk at the idle transfer port (where fuel is dispersed). Either would cause problems. The best fix is to do an easy rebuild/clean the carb...eddy's are pretty simple to rebuild. If you want to try cheap and easy, try some more fuel treatment for carbs, run it through. Also try a little shot of carb cleaner down the primaries and then a little tube just off each primary...understand, this isn't what I'D do, but MIGHT do the trick. Might make things worse too if you dislodge what ever is there and push it to a worse spot. Let her sit, then try starting her up and see how she does....

If you aren't certain around a carb, best thing is to take it to a pro to take care of it...

84hurst
08-04-2009, 02:31 PM
The first thing is like SS said...check for vacuum leaks always. Everything is connected, tightened, no craked hoses, etc...also check for vacuum leaks around the manifold/head. That is almost always the first thing to check.

It is probably your idle circuit...the resulting lack of fuel making it through is giving you the idle/part-throttle/cruise driveability problems, but doesn't factor much in WOT settings (The idle circuit still puts through pretty much the same amount of fuel at idle as it does for WOT...it just becomes a smaller percentage of the fuel for each setting). It's very easy for the circuit to get gunked up sitting for long periods. BUT, the fact that it's not at it's worst idling does give me a little pause.

While running the car on the road, put it under a progressive load...like speed up w/o downshifting. Don't use enough throttle to open the secondaries, but enought to go to the power enriching circuit on the primaries. It might still run a little rough, but it should improve considerably. If it does...almost certainly the idle circuit is the culprit. If not, it's probably something else.

There could then be a problem with the idle air bleeds (where air is drawn in), or perhaps there is gunk at the idle transfer port (where fuel is dispersed). Either would cause problems. The best fix is to do an easy rebuild/clean the carb...eddy's are pretty simple to rebuild. If you want to try cheap and easy, try some more fuel treatment for carbs, run it through. Also try a little shot of carb cleaner down the primaries and then a little tube just off each primary...understand, this isn't what I'D do, but MIGHT do the trick. Might make things worse too if you dislodge what ever is there and push it to a worse spot. Let her sit, then try starting her up and see how she does....

If you aren't certain around a carb, best thing is to take it to a pro to take care of it...

Wow, it sounds like you've dealt with this problem before! I'll look into the vacuum leaks, that circuit and the carb. Thanks guys!