O.k. I have a 81 Monte Carlo with a 350 rocket swapped in it with a 4 barrel Quadrajet. i don't know the year block it is YET... Anyways the car is SLOW, doesn't get up like a 350 rocket should, which leads me to think it's the timing.. it has an HEI conversion which i believe screwed everything up. I want to time the car but i don't have a timing light, nor do i know much about HEI's.. what information can i grab from just looking at the unit to help me figure out my problem? i know they have vacuum advanced, mechanic this and that, computer controlled HEI, non-computer controlled.. yeah i'm basically new to all this...  Anyways i can drive 12 miles and 10 dollars in GAS is burned up which also leads me to this conclusion, actually it was so bad i thought that the stock electric fuel pump was also running while the mechanical one was too!... What type of problem am i having?, is the timing retarded (lol) or advanced to much?? i don't think i've heard any pinging also... i'm also going to get a new set of spark plug wires, cap, rotor, and coil..

thank you

Alex  

That lack of power could be caused by a number of things like warn lobes on the cam,slack in the timing chain or just plain worn out. But the timing being retarded can also be the problem as well being to advanced should not make the engine sluggish or lack power. If the engine doesnot ping or bind when you are tring to start it most likely it is not to advanced.To set timing you should use a timing light but if you can't get your hands on one losen the distributor clamp bolt just enough to turn the distributor turning it clock wise should advance the timing but just turn it a hair at a time if you advance it to much it will ping or bind when tring to start it mostly when hot and could cause damage.Also check to see if the carb. is still dumping fuel after you shut it off remove air cleaner and when you shut it off look in the carb. to see if fuel is still dumping down the troat of the carb.  

engine has only 15k miles on it

can u do this with an HEI??

could this cause my car to run really rich and get horrible gas mileage  

As long as your Electric fuel pump is rated at less than 10psi (and possibly as high as 12psi) your float in the carbuerator shouldn't have a problem keeping fuel from flooding out the carb (providing it's in good clean working order).  Having your mechanical pump in series with it doesn't hurt it or effect it at all if the pump is good.

Before worrying about mileage I'd get timing on the mark first.  For a decent baseline with out a timing light you can do this. Loosen the distributor hold down bolt just enough to be able to turn the distributor but not loose enough that it rotates freely.  Start the car (make sure it is fully warmed up) and turn the distributor gently and slowly (if you don't want to get a small shock from the distributor while doing this either turn it by the vacuum advance or wear a thick glove) testing in both directions until you find the highest idle speed (by sound) or if you have a vacuum gauge find the highest vacuum.  If the engine isn't a high compression engine this setting should be fine with no pinging, if you get pinging on a test drive you will have to either run higher octane gas or turn the distributor a bit lowering the idle (and vacuum).  After each timing adjustment your idle RPM will probably have to be reset using the idle adjustment screw on the carbuerator.  Go low enough that the engine idles smoothly while in Drive and at a stop.  

After the timing is set drive it for a few days/week to see if the mileage improves.  Bad timing can have great negative effects on your mileage.  Be sure to use your vacuum advance and it is hooked to a vacuum source near the middle or top of the carbureator for best mileage.

Quadrajets are pretty much load sensitive carbs and it takes quite a bit for a Q-jet in good shape to kill gas mileage on a mild to docile engine.  If it is leaking fuel from gaskets, if debris or excessively high fuel pressure are keeping the float needle from seating then fuel will be wasted.

Hope this helps.  

thank you very much i will try this


hey i have the vacuum hose disconnected thats coming off the olds intake manifold (Driver side) .. where do this plug in, or do i need it??

looks like this http://www.fiatparts.com/P2140088.jpg but its actually IN the manifold  

Donot plug the vacuum advance directly to the manifold vacuum find a spot on the carb. should be on the drivers side of carb. distributor vacuum should be 0 at idle.  

Thats the thing.. i dont know where to plug the manifold vacuum too?? any pictures??  how can i test to see if my distributor vacuum is Zero at idle??  

place your finger over one port at a time and if you fell it sucking then that port has vacuum at idle also if you connect the vacuum hose to the vacuum advance canister on the distributor to a vacuum port and the idle raises up then it has vacuum at idle.  

GRR im confused ...... i ll see if i can get some pictures up  

a few questions..    any chance on what year the rocket came out of ...  and are you running the Qjet off the rocket or off the chevy???  with wires into the top and front???      the qjet carb number would be handy also..   drivers side... stampped verticaly.. 170??????   or 70????? the second line is just a date code and not needed to id the carb....

that way some of use with vacuum daigrams might be able to look up what you have and give you better advice...

and the plastic timing pointers are available... hopefully depending on the years...  sometimes... various cars used olds motors ...but you need a year to start out...  or someone will tell you where the engine  id number is stampped into the block..  the casting number should be above the timing cover... that would be a help...  

sure thing ill look into it when i get a chance... when the weather clears up  

Well I am not expert, but I learned some stuff while building my 72 Cutlass Conv. I did the HEI conversion on my 350. By chance I stumbled into a forum where I learned about the low voltage resistance wire from the ignition. This wire needs to be removed or bypassed and replaced with a #12 wire so that the HEI dist gets full voltage all the time. Originally the points received 12v from the starter sylenoid at starting and after it is running it maintains with about 7 volts or so from the ignition. If you did not make this change I can imagine that if your not getting a hot enough spark, then you wold have the lack of power ans poor fuel economy. Anyway you might already know all of this but this is my thought. Good luck.  Mike  

I should have proofed this before sending. Please excuse the spelling and typos....Good luck.  Mike