I have a new (to me) 1999 with a 5.9 in it. When I go to start it, it will often just crank and crank and crank and not start, only occasionally firing a little bit. If I stop cranking for 2-3 seconds, and try again, it fires right up.

I've checked the plugs-- they need to be replaced. The center electrode is rounded and the gap was out to .045 (which would explain the intermittant missing it was doing). I regapped them (missing mostly stopped) but am replacing them today, along w/ the wires. The missing mostly stopped with the regapping but the starting troubles didn't.

It seems to run fine-- lots of power, fuel mileage no more foul than usual. The only other thing I noticed while giving it the once-over is that the TB is pretty dirty. I plan on rectifying that today as well, but I don't think that would cause this problem... but I could be wrong.

Any ideas or suggestions?

Thanks!

 

Sounds like the pressure regulator on the fuel pump is bad.Get a fuel pressure tester and see if it holds pressure.

 

SHould I test the fuel pressure with the engine running or off?

How hard is it to get to? Does this indicate impending fuel pump failure? I'll have to do it myself if the extended warranty doesn't cover it (which it should).

Thanks man

 

Most of them have a test port on the driver side fuel rail near where the hose connects. You want to check it when it's running. Should be about 49 psi. Then shut the motor off and see what the needle does. The pressure should stay up.


When you are cranking the motor does it turn over slow or normally. And also does it only do this the first time you start it each day, or every time you start?

And btw, read directions with tester, safety first. Put the tester on before you start it.

 

Fair enough. Now, what sort of pricing should I be looking at for a fuel pressure testing gauge? The only one I've looked at so far is at Advance Auto Parts, and it's 40 bucks. That seems high for what it is. Is this typical or should I be able to find something serviceable for cheaper?

Thanks!

 

You could try ebay, and there are numerous places on the internet you can get them for less. There is one place that a lot of people here get tools from , but, I'll be darned if I can remember the name. I guess it all depends how fast you want it . And 40 bucks is not bad , the tool will do other vehicles also. That and a vacuum gauge are really good diagnostic tools to have.

 

OK, so I went and picked up the 40 dollar one from CHecker. I pulled the relay and relieved the pressure by running the truck til it died. I then hooked up the gauge, put in the relay, and turned the ignition on (not starting the car). The pressure shot up to about 40 then rapidly went down to about 10. When I tried to start the car it wouldn't start like usual, waited a couple of secs, tried again and it started right up. I checked the pressure and it was at about 50. I then turned it off and by the time I got around to the fron again it was at 30 and falling, down to about 10.

Just to verify this was abnormal behaviour I tried it on my wife's vehicle and it maintained pressure just fine.

So this is the FPR for sure at this point, isn't it? Hopefully since it's integrated into the fuel pump the warranty will consider it "fuel pump" as the whole thing will need to be replaced (correct me if I'm wrong).

Is my analysis correct?

Thanks!

 

try harborfreight.com for decent cheap tools. They have brick and mortar stores in some bigger cities.

 

The regulator on the pump is bad! Or you have some seriously bad leaking injectors , or you have a fuel line leak. Since it drops in pressure that quick. If you have the original pump in there it is bad for sure. You can actually get just the regulator from the dealer. But you still have to drop the tank pretty much to install it. So you might as well get a new pump and be done with it. And don 't get a CARTER Fuel PUMP. I personally have had nothing but probs with them to this point.

 

Oh and thanks AIM, Harbor Freight is the vendor I could not remember the name of.