TransAm_85

I just finished putting a 350 out of a 93 chevy van in my car. It has a edelbrock performer intake 2104 with a 750cfm edelbrock performer carb on top of it. It has a vacuum advanced mechanical distributor. It has a mechanical fuel pump on it. It starts when cold or hot. It just bogs intill it hits 2000 and then it takes off. Any ideas would be would be great.

TransAm_85

?????????

Rolling Thunder

Is the top end all new stuff (carb distributor ect). Does it bog hot and cold? What is the timing set at? Make sure the vacuum advance line is plugged into the right port on the carb. Next with the car off remove the air cleaner and look down into the carb. Hit the throttle and you should see fuel squirt into the carb. Finally pull a plug or two out what color are they?

TransAm_85

The carb is almost new i had it on my 305 for a couple months then i sprayed it down with wd-40 and put it back in the box.. The distributor shaft my dad had it is a GM distributor. If its cold like right after i start it it will die if i punch the gas. when its warm it bogs intill it hit 2000 rmp then it takes off. The timeing was at 8 but had to advance it to run better. not sure were its a now i adjusted it by ear. Cant tell you what color the plugs are they are brand new. the carb is a 750cfm calibrated for performance. the fuel pump is the stock one off the 305. Im getting gas i watched it spray into the carb while reving it up. the vacuum is pluged into the port on the right side of the carb and the left side is pluged off.

da.slyboy

iTrader: (1)

Sounds like the air/fuel ratio is off. Does your carb have electric choke? Is it working property and not getting stuck.

Rolling Thunder

Yea it probably wouldnt run well at 7 degrees. For something like that ide say more like 10-12 degrees. Next the vacuum for the distributor isnt the ported vacuum on the left side of the carb? At idle there should be no vacuum or virtually none. If theres alot of vacuum then its just strait manifold vacuum not the one for the distributor. Next up if im not mistaken a stock 305 pump dosnt put out enough pressure to run a carb like that. As i recall my edelbrocks run like 5.5 psi (max of 6) and my old 305 pump only put out like 3-4 psi. Next performance carbs on stock motors alot of times will not run so well. There over enriched to compensate for things like big cams. Things may also be calibrated to run at lower manifold vacuum. For example the metering rods may be designed with lighter springs so that there not operating even at idle on a car with a big cam.

TransAm_85

Its a manual choke. Its not hooked up. I need a diff cable to hook it up.

TransAm_85

so which side do i hook the carb up to? Right or left? My plan for the carb is to put new jets and rod in it to make it a 600cfm. i have good fuel pressure. I think its running to rich the eshaust smells bad and it makes you eyes water. I will get a fuel pressure gage and test the pump. So what is my problem the carb, distributor or fuel pump?

Rolling Thunder

Well you actually cant turn a 750 cfm carb into a 600 cfm carb with different jets and rods its the bores in the carb itself that determin the CFMs. The only thing you can do with rods and jets is change the enrichment under various amounts of load. As far as which side to hook the distributor too hook it to the port that has virtually no or little vacuum on it. Youll deffinetly be able to feel a difference between the left and the right sides when you put your finger over the port. Although on my edelbrock performer its on the left side of the carb. Its hard to say exactly where your problem is at this point but im leaning twords the fuel side of things eather a pump thats not producing enough presser to run the carb well or the carberator is calibrated wrong. Now you said that you have a manual choke it is in the wide open position right? Because if the choke was closed that would cause it to run pretty rich. Have you tried turning in the idle mixture screws? (clockwise to lean counterclockwise to enrich).

TransAm_85

The distributor was hooked up to the wrong side. I changed it over to the other side then it backfire and blew smoke out the carb. So i advanced the timing to get it to run better the bogs not at bad now. But the timing mark is not on the tab. The choke is fine its all the way open. the carb comes with metering jet- primary.113 secondary.107 Metering rods .071x.047 with orange 5"hg spring. Yes i have tryed to tune it myself it dont help.

Rolling Thunder

If the timing mark is not on the tab usually thats an indication that you have the vacuum avdance hooked up to strait manifold vacuum so are you shure you have the vacuum advance hooked up to the port that has little or no vacuum at idle? The other possability is that your timing chain cover/tab is not matched to the right harmonic balancer but thats kinda unlikely as i assume they came with the motor. What probably happened was you had it hooked up to the right port and then hooked it to strait manifold vacuum which advanced the timing causing a back fire and then retarded the timeing to account for the difference. Advanced timing helps alot when it comes to bogging and improveing the peppyness of the car. Well because your running a relitivly large carb for that motor thats designed for large displacement SBC, BBCs, or for high RPM operation we may not be able to get rid of the bog completely. However there is a tuneing procedure in the manual if you still have it. After running through the tuning procedure you should atleast be able to get rid of the overly rich mixture. Hav you tried checking for vacuum leaks?

TransAm_85

I have the vacuum hooked up the right way now. But im still not on the timing tab.The harmonic balancer is off my 85 305 and the timing cover is the one that was on it.I had to use the harmonic balancer from the 305 beacuse they are different thickness and it would have put my pullys out of line. I will check for vacuum leaks when i can pull it back in the garage.

Rolling Thunder

Oh well that might have thrown things off a bit with the timing tab. Ide recomend finding TDC #1 and making a new etch in the harmonic balancer in the correct place. Although the harmonic balancer is thicker for 350s (to better control vibrations) it shouldnt effect how the pullies line up? Anyways yea deffinetly check for vacuum leaks and test the fuel pressure to see how it does. That would be the next logical step.

TransAm_85

The 350 harmonic balancer was thiner and bigger around. I used all the stuff off the front of the 305. I put the v belts back on it the pully bolts to the harmonic balancer so if it thiner the pully wont be in the right place.