About to give up... need help

[cammed89lx]

Hello all.. first off, im on my last leg with this car, its an 89 lx. under 5k on 306 motor, almost everything is brand new.. afr 165 heads,f303 cam, 650 carburetor,edelbrock intake, kb pistons, t5 tranny. So anyway just got the car back from the shop today(got the inner tie rods replaced) so after i drive it around for about 30 min, seeing how they did, i decide to get on it, to about 4600rpm not even that hard, and as soon as i put it into nuetral its as if the carb flooded, and was choking real bad.. it used to do this so i was like ok ill let it sit...

So after letting it sit for about 30 min i start it back up and its doing the same thing, will barely hold an idle, idling at probably 400 rpm. it sounds like a misfire, and runs like crap. and once i rev it it wont rev until after my foot comes of the pedal, its weird. its like its choking the whole time my foots on the pedal but once my foots off it revs.. I dont know why. so i took the filter off to see if maybe something was cloggd somewhere...nothin. So let it sit for 2 hours hoping it was just flooded still. I start it up after letting it sit, and it just wants to die. I manage to get it home by reving the car up to 2k rpm before putting it into gear or else it would just die on me.

If anybody has any idea at all I would love to hear any thoughts, i have almost had it with this car. Sounds something carb related but am not that familiar with carbs so again. please help if you can, sorry about this being so long, and.. damn cars are legit $ pits. Thank you all

 

[bmo37]

Hello all.. first off, im on my last leg with this car, its an 89 lx. under 5k on 306 motor, almost everything is brand new.. afr 165 heads,f303 cam, 650 carburetor,edelbrock intake, kb pistons, t5 tranny. So anyway just got the car back from the shop today(got the inner tie rods replaced) so after i drive it around for about 30 min, seeing how they did, i decide to get on it, to about 4600rpm not even that hard, and as soon as i put it into nuetral its as if the carb flooded, and was choking real bad.. it used to do this so i was like ok ill let it sit...

So after letting it sit for about 30 min i start it back up and its doing the same thing, will barely hold an idle, idling at probably 400 rpm. it sounds like a misfire, and runs like crap. and once i rev it it wont rev until after my foot comes of the pedal, its weird. its like its choking the whole time my foots on the pedal but once my foots off it revs.. I dont know why. so i took the filter off to see if maybe something was cloggd somewhere...nothin. So let it sit for 2 hours hoping it was just flooded still. I start it up after letting it sit, and it just wants to die. I manage to get it home by reving the car up to 2k rpm before putting it into gear or else it would just die on me.

If anybody has any idea at all I would love to hear any thoughts, i have almost had it with this car. Sounds something carb related but am not that familiar with carbs so again. please help if you can, sorry about this being so long, and.. damn cars are legit $ pits. Thank you all

Sounds to me like a fuel filter being clogged, or the fuel pump is dying. Its also possible the that something funy with your carb is going on, jetting could have something clogged it or the floats could be off.

 

[cammed89lx]

thanks for responding bmo37, and yea the only thing not new on the car is the carb. it was used, but it i s a floatless carb. and im gunna check the fuel filter too. something sounds sketchy. thank yuo for your input.

 

[LarsD]

Floatless carb? What?

Might want to pull your plugs and make sure they aren't fouled. Otherwise you might get it figured out, and not know it, cause the plugs won't let it run right.

 

[HiFlow5 0]

Remember your basics; fuel, spark and air.

You said you already checked the air way so that somewhat rules that out. As mentioned I would first check the plugs, are you running rich? Do you have a fuel pressure gauge hooked up, if not, see if a buddy has an on the line gauge you could borrow. Check to see what your FP is at idle and under acceleration if possible.

How is the timing on the car, what * are you set to? Is each cylinder getting spark?

That's where I would start, that info would help a lot in diagnosing your issue.

-Craig

 

[LarsD]

Also, are you running a mechanical fuel pump or an electric? If electric, is it an in tank pump, of an external? Are you running any kind of regulator?

 

[cammed89lx]

the fuel pressure at idle is set to 7 psi. and i think its running rich but its been that way for a while, and timing is set to 34 dgrees. and its an electric fuel pump, and i dont know whether its in tank or outt of tank. and ill have to check my plugs

 

[michaelg10]

post up a pic of the floatless carb

if its a Holley check the jets

also check the return spring on your accelerator linkage at WOT to ensure it is functioning properly. Some guys add a second spring to remedy a sticky pedal.

 

[michaelg10]

if its an edelbrock check the metering rods

 

[cammed89lx]

yea, its a holley carb. and i have no idea how to post pictures(not technologically smart), i am sorry.

 

[blue351lx]

Blown power valve on carburetor.

 

[Whiplash-Smile]

x2^^^^^^^^^^^^^^
On the "floatless" carb are the float adjusters(big flathead screw on top of a 5/8" locknut) dead center or off to one side of the float bowl?

You said 650 so I am going to assume centerhung mech. secondaries or 650 "Doublepumper" which is quite a bit more carb than you need with your motor combo.

My advice is look around for a good used 600 Vac. secondaries or better yet just give Summit a call and get a new one - also buy a vacuum spring assortment for the secondary pot and a couple sets of richer jets(though you might be just fine as delivered) these carbs are simple and all the secondary work is done for you, and are perfect for a mild motor around town or at the strip. You may need a different Power Valve than what came stock depending on your elevation - the "F" cam won't need a change by itself though, and with the 3rd weakest spring in the assortment secondaries will kick in right at 38-4100 and should pin you..

Best off you can turn around and sell the 650 douple pumper in a heartbeat.. and trust me you won't miss it.

 

[Gen414]

Well, it's not floatless. Maybe you don't have the clear sight glass for your floats, but it does have floats.

I would start off by having the float level checked. Also, other things that need to be checked (and others have mentioned)

Powervalve
Fuel filter
Jets
Linkage for binding and free and clear travel
Timing...do you know if distributor is "locked" out? Vacuum advance? Or Mechanical? If vaccum, check source of vaccum. If mechanical, check springs.
Spark plugs, gapped correctly? Too cold of a plug maybe???
Wires...new? Used? If used, do Ohm resistance check make sure wires are good.

I bet your problem lies in one (or more) of teh above. Good luck.

 

[StormWatch]

Get hour hands on another carb and see if it does the same thing. Borrow one if you can.

To me, it sounds like the carb is very far out of tune or it's time for a rebuild