Q: I have a 1999 Chevy Suburban 1500 V-8. Frequently the car won't start. The engine turns over but won't catch. The odd thing is that there is a sequence of actions to get it to start that works every time. If I repeatedly crank three times and let it rest for two minutes, five times, it starts right up every time! No one has been able to find any reason for this to occur and why the solution works every time. Any ideas?
A: I suspect a lack of fuel pressure is the issue. Deposits on the CPFI — central port fuel injection — can "stick" the injection poppet valves. GM's Port Fuel Injector Gasoline Detergent or SeaFoam may help this scenario. In fact, GM warranted this condition for 10 years/200,000 miles.
Do you hear the fuel pump run when you initially turn on the key? It should run for two seconds and then stop if you don't engage the starter. If you don't hear it, have someone tap the bottom of the fuel tank with a rubber hammer as you crank the engine. This may "jump start" a tired fuel pump.
Monitoring fuel pressure with a gauge would tell whether fuel pressure comes up to the necessary 60 to 66 psi with the key on, ready to start. Other possibilities include a leaky fuel pressure regulator, fuel pulsator/damper in the tank, faulty fuel pump relay or low battery voltage while cranking the engine.
More on brake rotors
In response to my column addressing brake rotor warpage on a 2005 Jeep Grand Cherokee, here are a couple of interesting responses.
From Robert Grussendorf: I had problems with warping front rotors on my 2000 Chevy Z28. I switched to drilled and vented aftermarket rotors. That was the end of vibration when braking. I was told the drilled rotors do a better job of dissipating heat.
PB: The idea behind drilled and vented brake rotors is simple — better and faster heat dissipation. As I mentioned, upgraded rotors may well alleviate the repeated rotor warping. However, I'm not convinced that drilling brake rotors is the right answer. Maybe this is the result of my experiences in racing, but on the occasions where a rotor ended up cracking, the origin of the crack was one of the drilled holes. Vented rotors, on the other hand, are cast that way and less likely to be the source of cracking. Like I said, I may be somewhat biased here.
From John Seymour: My wife and I have a 2008 Cadillac DTS. We drive cross-country twice a year over the Western mountains. On the downgrades we developed rotor warp that was severe enough to make us stop at a dealership in Colorado. We were told to downshift, and we do that sometimes, even into second gear. I have never had to do this with any other car and it seems to me to be an under-designed brake system. Should we go to replacement rotors or is there something else we should do first?
PB: Regarding the Cadillac's warped rotors, I tend to agree that the long downgrades described are overheating the rotors, causing them to warp. Better aftermarket rotors may well help, but first focus on what you, the driver, can do to minimize heat buildup in the brakes.
In situations like this, try to use the brakes as little as possible and always focus on using them as briefly on each application as possible. Rather than applying continuous light braking while rolling downhill, try to rhythmically brake moderately for a short distance, then release the brakes to let them cool. And downshifting makes good sense, particularly with many modern automobiles that do not provide engine braking in "D" due to the overrun clutch on the output shaft. Engine braking is provided by manually downshifting to a lower gear. Allowing the engine to help slow the vehicle is in no way damaging to the drivetrain.
