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#5522 of 5658 Re: 1979 oldsmobile regency 98 - slow to start - cause? [heritageadam]
Apr 25, 2012 (2:48 am)
Two wild guesses:
-Weak fuel pump. It has to 'prime' up everything for the first start, and this might take more time.
-Bad 'power valve' in the carb. This is a little diaphram pump valve that gives the carb a 'shot' of gas directly into the carb throat when you depress the footfeed. When the car is running at speed, if it will not accelerate quickly when you push on the footfeed, this most probably is the problem. A carb overhaul kit always comes wiht a new 'power valve'.
#5523 of 5658 Re: 1979 oldsmobile regency 98 - slow to start - cause? [heritageadam]
Apr 25, 2012 (5:52 am)
>the choke closes appropriately. Then I turn the key and with either holding the pedal to the floor or pumping the pedal (doesn't matter) the starter turns and turns for 5-10 seconds, then all of a sudden it fires up.
Are you sure the choke is closing completely to block off most air flow? I suspect that it is, but you might take the air cleaner off and observe the choke when it's cold while someone else cranks the engine to be sure the spring closing the choke isn't weakened and the air flow at crank speed is pulling it open slight??? I may be overthinking the history of these, but age on the choke springs in a few cars mandated replacing the choke.
You don't say where you are so I don't know if "cold" is 30 deg or 55 degrees. BUT my #1 guess on this is leaking of gasoline through the plugs in the bottom of the carburetor. If I recall correctly, the plugs are put in to seal passages that had to be drilled inside the carb but went through the outside. These seep slightly as the carb cools and the gas level in the bowl leaks. I don't recall if it leaks onto the manifold or internally inside the manifold. So it takes little time for the fuel pump to refill the carb float chamber to a level where the jets and suck fuel instead of just air.
You might do some internet searching for this--QuadraJet is the carburetor. The 4-barrel version had this. I don't know if the two-barrel version had it as well. I seem to recall talk of epoxy to try to seal the plugs better from the outside?
A test to do, would be to take off the cover on the carb (only if you have done before and can do it right and check the level of fuel after engine has sat. There is a depth dimension from the top of the edge of the float chamber in books.
OR you can see if you can have air cleaner off, open the choke butterfly, and pump the accelerator rod and get gasoline through the accelerator pump. And see how many pumps of gas it gives. Then compare with what the quantity of gas is after car has sat just for a couple hours and cooled down during daytime driving.
>either holding the pedal to the floor or pumping the pedal
I believe the correct starting procedure is to just push down on pedal one time before cranking to allow the choke butterfly to close with its spring pressure. Then keep your foot off the accelerator pedal while cranking.
Holding the pedal to the floor actually moves a cam that opens the butterfly choke valve, eliminating choking for when the engine has been flooded. So don't hold the pedal to the floor during normal cranking.
I had a Quadrajet Olds 350 in 1977 but traded it for a 1980 with the two hole version for better fuel mileage. I didn't have trouble with mine, but it may now have aged enough to start seeping where it lengthened crank time.
#5524 of 5658 Re: 1979 oldsmobile regency 98 - slow to start - cause? [heritageadam]
by Mr_Shiftright HOST
Apr 25, 2012 (8:44 am)
Well in theory, holding your foot to the floor defeats the choke. If the car were ship-shape, all you should have to do is pump the gas once, then don't hit the gas pedal again, and just crank it (well, maybe tickle the gas pedal just a tiny bit).
However, if say your float is defective, you might be dribbling gas into the engine overnight, thereby creating a flooding condition even before you start the car--and this you are "curing" by flooring the gas pedal.
So if I were you, I'd try two experiments and then report back:
Day One -- get in, pump the gas once, crank it without doing much of anything to the gas---what happens?
Day Two -- get in, floor the gas pedal and keep it there, crank it---what happens? Better or worse than Day One?
Day Three -- get in, don't do anything, just crank it---what happens?
#5525 of 5658 2002 Dodge Dakota Sport brake light problem
May 07, 2012 (1:11 pm)
We have had a problem with the left rear brake light only working intermittently. One day it will work--next nothing. All other lights on that side and the entire truck are good. Bulbs have been replaced, new housing unit and new wiring harness. The fuses are good. Now it won't work at all! Any suggestions?
#5526 of 5658 Re: 2002 Dodge Dakota Sport brake light problem [msrose59]
May 07, 2012 (4:28 pm)
You mention a new wiring harness and bezel bulb holding unit. While I am not familiar with the set-up on your exact vehicle, the fact that you had an intermittent issue before and now have a fullt-ime failure, suggests that there is a bad slip-on connector involved be it a crimp type or otherwise. I have seen connectors look perfectly new-like, yet by bypassing a jumper to correct terminal at bulb to upstream of the supply wire (puncture with a needle, then silicone the point of entry after) it often reveals a bad connector. I have taken a said connector apart after replacing it and was shocked to see inside a green electrolysis corrosion that actually was the culprit, and odd as it seems, there were no external visual clues of that corrosion. Fortunately it is rare, but happens and I learned the hard way this scenario spending not just hours, but even over a day troubleshooting, and each time always looking at the connectors and saying to myself that they all look like new (on the outside). When trying to rule out a bad connector, remember to include the ground if a separate ground is used on each filament. i.e. The tail light and backup lights in same bezel work fine but do not assume they all use the same ground. Without access to the vehicle in person, that's the best I can suggest online.
Also, I doubt the brake light switch (down at the pedal) has separate dual terminals for left and right, but if it has more than 2 wires coming off it, then ensure it is not the culprit. Wiggling while someone watches would help rule it out, but if salt off your feet in that type of climate, and position of switch allows that corrosion, then it could get into switch and wiggling will not work. Again though, I doubt it has a dual circuit to the rear. Also rule out a potential trailer towing controller, or wire harness if that exists on your vehicle.
If vehicle has been in accident of a nature that would involve wire harness repair or replacement, then that too could be suspect. I assume you did not replace the entire harness from front to back.
Replacing any harness or part that ends up with a full-time failure vs intermittent before, is your best clue as to where to look.
#5527 of 5658 Re: 2002 Dodge Dakota Sport brake light problem [gimmestdtranny]
May 07, 2012 (9:06 pm)
TY! Will check all of this out. The truck does have a dent at the back area that suggests this entire lens may have had damage and been replaced so that may be a factor.
#5528 of 5658 Re: 2002 Dodge Dakota Sport brake light problem [msrose59]
May 08, 2012 (1:18 pm)
If there is an added trailer wiring harness, this could be what has messed things up. If there is one, and you will not pull a trailer. take it off. I've seen several where they cut into the wires and generally messed things up.
#5530 of 5658 Re: 44444 [qaz444]
May 17, 2012 (9:44 pm)
I totally agree. Couldn't have said it better!
#5531 of 5658 Ideas why my truck doesn't start?
Jun 06, 2012 (8:40 pm)
Hello. A question for the experts. Sorry for the length but I think I ned to fill in all the details.
I have a 1986 Mazda B2000 pickup. It's been very hardworking for many years, with a few issues along the way. It used to get hot in the summer so one year I took out the thermostat. Never got hot after that. I drove it that way fine for about five or six years.
I took the truck in for smog the other day and they put a thermostat back in to get it to temp. It has passed smog twice before with no thermostat with other smog people but these people said they couldn't do it without a thermostat.
After fiddling with the truck for hours and $228 dollars later they finally got it to compliance. The next day or maybe the day after that it was hot weather out. As I was driving up a long grade here I started to smell burning oil. At first I thought it was someone else. When I got to a place in town and stopped I now noticed that smoke was billowing out from under the hood.
After letting it cool I took off the radiator cap and saw that there was no water. When I filled it I noticed that it was now dripping rapidly out from a hose underneath the carburetor (in a very inconvenient location I might add). I had to pick up my daughter from school so I filled it back up (I also took a five gallon bucket of water) and with a little difficulty got it started and went and got her. It is another 17 miles from there to home. My plan was to watch the gauge and when it started getting too hot to turn it off and let it cool down. I just wanted to get us home.
About halfway home when the temps began to rise abnormally I turned it off. Problem was that when it cooled down it wouldn't start up this time. Still won't. It cranks, the timing belt is good, there is a spark to all the plugs, the tank is full of gas but there is no turnover. I tried putting a little gas in the carburetor but still no ignition.
I'm wondering if it might be a clogged fuel filter or maybe the pump went bad from the heat. I asked someone else who told me that I might have blown the rings and lost compression.
I had to get another vehicle but I want to see if I can get the truck going again. Why? I live in California where you can collect some money to retire old vehicles. The catch is that you have to be able to drive the car to the dismantler. It's frustrating knowing that if I had not gone to these smog people I could have recycled this truck without a problem.
Anyway, I am wondering if anyone has any other ideas as to what may be causing the truck not to start? It cranks, and almost seems like it wants to start but doesn't.