By jcw on Wednesday, May 30, 2001 - 10:04 pm: Edit

'95 Disco...starts right up when cold or when warm but not sitting long. If it's been sitting for awhile, it'll crank a lot before starting...but if gas pedal is pushed maybe half way down, it'll start pretty quickly. My '94 Disco doesn't do this. Any ideas?
Thanks.
John

By Jon on Thursday, May 31, 2001 - 10:04 am: Edit

Sounds to me like the prime pressure is escaping from your fuel system. Try this: When you get in to start-up after it's been sitting like you say, turn the key to the run position (what the key returns to after you've cranked the starter) for several seconds before cranking, then proceed to crank the engine. What that will do is turn the fuel pump on, which will prime the fuel system, and you shouldn't have any problem starting quickly. I had a car that did the same thing. Never found the pressure leak, but priming the fuel system like I said cured the long cranking effort. When you press the accelerator, it tells the computer to inject more gas, which apparently works to start your truck. Some cars you can do that, but most computers interpret it as a "flooded throttle" and will cut off the fuel pump until the engine burns out the imagined excess fuel, or until you stop cranking. But try the process I mentioned and let us know what happens...

By Jon on Thursday, May 31, 2001 - 10:11 am: Edit

P.S. In the meantime, check all your fuel line connections for possible leaks, and check the fuel rail on the engine and all the vacuum connections. I think this problem can be caused by a faulty fuel pressure regulator. I don't know how much they cost, though. Must've been enough for me to not worry about it with my old car...

By jcw on Wednesday, June 13, 2001 - 08:43 am: Edit

Update...
Letting the fuel pump build up before cranking doesn't change things. And, a fuel pressure gauge on the Schrader valve shows quick buildup and good pressure (35 psi) in any case. And the pressure holds well when the key is turned off..so I don't think it's a fuel pressure problem. Thought it might be a temp sensor...the ECU thinking the engine was cold..
So, replaced the sensor I think the ECU reads...the one just behind the distributor with the weather-proof connector. There's a single-wire one behind that, which I think is the gauge sensor, which I didn't change. No help. Then, swapped the fuel temp sensor from my '94 Disco, no change. Also tried disconnecting the vac hose from the fuel pressure regulator..no change. Sucking on the hose while cranking..no change. And, the fp reg vac diaphragm does hold pressure ok.

Incidentally, if I start it by holding the pedal down, it idles fine after letting up on the pedal. And then, turn off, start again, starts normally with no pedal and no excessive cranking. Sounds almost like vapor lock, but can that happen when the fuel pressure is good?

Sure would like to have data on the computer interface, ala TestBook. I've got a scan tool for my '92 Suburban, and it's great to watch all the engine parameters in real-time. Anybody have pinout info on the data connector? I'm thinking of experimenting to try to build an interface.

Any suggestions on the cranking are appreciated.

John

By Lino Palumbo on Friday, June 22, 2001 - 08:05 am: Edit

I have a 95 Disco also and I noticed that when its cold (winter) it does the exact same thing. The dealers answer was to replace the starter with a new faster turning one and a new battery cable lead to starter (bigger gauge). They say the engine does not turn fast enough, but I don't think thats the problem and If it is I would rather change my battery to keep it spinning at least the way it is then to put another starter.
if you do find it let me know
Lino