WhiteWindsor

Engine specs are listed in my sig. I have a problem with running rich. Dark smoke at idle and fouled plugs. Anything after 3000 rpm is no problem. But at idle and when i first hit the gas it smokes. I did a compression test to make sure no problems with rings or valves. All cylinders were between 180-185 psi. The HP 750 comes stock with a 6.5 power valve. Holley said to take vacuum reading @ idle and divide that number by 2. My vacuum at idle is 5.5 psi so i put a 2.5 power valve in and still have same problem. Never had any problems with car idling. Rpm at idle is around 1000-1100. The car runs great and is very fast. But is burning so rich at idle it makes my eyes water. Even with the set-up it is not bad on street, have never at it cut off on me. Trying to fix what i can before i get a dyno tune. And i am not sure that will help my rich problem. The car was built to scream but cant always do that on the street.
Thanks

Hurricanedt77

Maybe it needs to be jetted, I guess that's possible. Or your idle air mixture screws could be set wrong. But anyway, we have a similar setup you just have more cam and worked heads. What kind of power are you making to the wheels, have you raced any cars yet. Are you pleased with the step up in torque from the 302? Get bakc to me, i'm very interested

WhiteWindsor

Thanks for the response. I have not had it dynoed. That may be next step and let them tune the carb. I have not taken it to the track yet. I have two friend who race, one runs 11.02 with a 175 shot and he swears my car is a very low 11 sec car on motor. The other friend races a s-10 with a 406, also very low 11's with nitrous and he also swears my car will run low 11's on motor, but i have yet to find out. I plan on putting a 150 shot on car soon, so maybe i can somehow get in the 10's.But i have foolishy raced everything on the street i can find. Have yet to have anybody come close. I have taken WS6, a 69 camaro SS, lots of mustangs and cobras. Had a guy in a new saleen pull beside me last week and started from a 40 m.p.h. roll and killed him. We pulled over and i said i would like to meet him at the track. He says there is now way he could hang. The next day a coupe with a turbo come beside me revving his motor. I had a car in front of me so i just pulled behind him and he took off. It was a joke, i would punch it and pull up on his bumper and back off 100 ft and pull to his bumper again. Did this 4 times and we get to a stop light and i pull beside him and for some reason he gives me a eat **** look.LOL. And then his car died and he could not get it started he had all kind of traffic blocked behind him. I would have give him a hand but he was being the smart *** by revving his engine at me in the first place. Torque is awesome on this car. I had a coupe and hatch i sold before buying this one and it is apples and oranges.

Hurricanedt77

Yeah let me know what happens with the carb, hopefully it works out.
I'm glad its fast, that means I have somethhing to look forward to.
I just cant wait to smash on people
I'll do as much smashing as I can before I break my t5

JD1969

Do the idle mix screws do much when you turn them in? The engine should die out before the bottom out. If they really don't do much you might want to check that the idle transfer slot and the butterfly is adjusted right. To do this you need to take the carb off and turn it over. You will see a tiny slot in the venturi, the throttle blade should sit about in the middle of this slot, there is a set screw to adjust this. Also make sure the air bleeds are not clogged. Does the HP 750 have screw in airbleeds and did anyone ever mess with them? There are lots of little things it could be, but nothing too hard to deal with. I doubt it's the jets as they really only come into play at part throttle and WOT.

my77stang

my first thought was the idle mix screws, take em in and then compensate it wanting to die with a bump of the idle screw if you have to, but bring those puppies on in.