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| Situation | The 35 Chev has been equipped with Holley 600 cfm 4 barrel double pumper
carburetor. Pretty standard stuff and very dependable.
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| The Choke |
The car was built with no choke - manual or otherwise. Now I'm sure on the warm summer days, this is not an issue, but for us Canadians, most of the Rodding season experiences cool (and cold) mornings and evenings. Starting a small block Chevy with this set up can be challenging at teh best and you often couldn't pull away (without stalling) until the engine had 5 minutes to warm up. The choke plates were installed in the carb, just clamped open. I looked into adding an automatic choke, these cost about $100 Cdn and required an electrical connection to the ignition. A manual choke on the other hand comprised of a $20 choke cable and knob. I opted for the manual choke on tow fronts - cost and its more fun to manipulate a manual choke. As I was rebuilding the headlight / windshield wiper switch bracket, it was no issue to add a third spot for the choke. This panel is attached to the bottom edge of the dash board to the left of the steering column. A very inobtrusive location and with the panel painted black, you wouldn't know it was there unless I pointed it out. The Choke cable snakes down by the steering column and passes through the fire wall next to the wire harness, across the back of the engine block and over to the choke housing on the right side of the engine.
It is now a simple task of setting the choke first when starting the car. Sure makes
starting the car a whole lot more enjoyable.
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| The Missing Vacuum Port Plug |
As any rightous man does with a new investment, we examined the new car with a fine
toothed comb. In the process we discovered one of the vacuum ports was left unplugged. On went a plug and down the road we went. Funny you know, I had to keep the choke partly on in order for the car to run smoothly. Gas consumption was certainly more than normal. In the end, I removed the plug and found the car ran just fine. I wonder if there was a hose attached to this port when the carb was originaly set up. So next time I have the car in for work, I'll have the carb adjusted to run with this port plugged as it should be. |
| The Floats |
Last fall (Nov'01) I went down to the local gas station with some friends of my wife.
They were rather enthused about the Rod and appreciated the opportunity for a spin.
Well we went down the road rather enthusiasticaly and then the car started acting up. Running
really rough. Well we limped back home and parked her in the garage. As this was the end
of the rodding season, I wasn't too upset though rather dissappointed another problem
had cropped up. Come March after the snow had finally left, I rolled the car out of the garage and started her up. Fearing the worst, the car started up fine and ran for aobut 20 seconds before the symptoms returned. This behaviour was consistent on a number of attempts over the following days. I invited my friend Bob to came over and we started diagnosing the problem. My fear was a ring or valve job was required. Bob checked out everything. We eventually took the air filter off and ran the engine. Bob found the problem immediately, the back two barrels were literally pouring gas into the engine. What we were experiencing was the engine running on the front two barrels as normal while the back two were pumping gas in. Eventually the pool of gas in the back barrels seeped past the choke plates and flooded the engine. Simple senerio, but what was casuing it? Bob explained that the fuel pump was pushing the gas in to the barrels most likely because the float valve was stuck open. After a few phone calls to garages and fellow Rodders I decided to remove the carb from the car and investigate further. With the carb on the bench, the rear fuel bowl was carefully removed and examined. The brass float appeared to be sound and empty of fuel. It is not unusual to have a plastic float deteriote and sink causing the float valve to remain open. I pulled the needle valve assembly out being carefull not to change it's setting. It too appeared to be operating fine. The whole lot was reassembled (with a new metering gasket) and returned to the car. Now the car was running just fine. I can only propose that I had some dirt in the needle valve causing it to remain open allowing the fuel pump to force gas into the rear barrels. With removing the needle valve. The dirt was inherently cleaned out. Subsequent to this experience the carb has twice more acted up, once again with the rear pump and also with the front. Knowing what the problem was, I have become proficient at pulling the needle valve out from above (see photo below), blowing out the seat and replacing it in the space of 5 minutes. Of course that isn't the right solution, so a proper approach was required.
As I suspected dirt in the fuel line, the logical things would be to change the fuel filter. There is a fuel filter on the car, right above the gas tank in a location that is impossible to reach short of dropping out the gas tank! Assuming the worse, I chose to add a second filter as close to the carb as possible to catch any dirt that may have entered the system from teh gas pump, tank, fuel line and even fuel pump. The filter is a glass cylinder with a replaceable core. I found this at a Speed Shop though you can also order it through Canadian Tire.
I cut back enough pipe to allow for the filter and a bend in each rubber hose piece. A miniature pipe cutter was used to cut the hard line due to the tight space constraints and to minimize loose metal filings. It was then a simple matter of cutting a couple of length of hose and clamping it all together. Don't forget to take into account the fuel flow direction of the filter! It's been three weeks now and I haven't had a repeat of the float problem. Keep your fingers crossed. Of course, at a recent Show & Shine, I did notice a number of the other Rods were also equiped with the same filter in the same location! Coincidence?
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