Will this stop a truck from starting?...........Thax.

More info please...

Sure....I put an new fuel pump in my truck and upon installing the tank the rollover valve was damage (the nipple were the hose go)and I'm curios if that valve will stop a truck from starting? I'm thinking that the pump is at fault.(bad pump)I know I'm going to have to drop the tank again anyway. My thinking is the valve(rollover) it's purpose is to kill the pump incase of the truck does an barrel row. Am I thinking this right?



P.S also is that rollover valve something that can be purchase from the local auto parts supply place or a dealer item?......Thaxs

what year truck

[quote=mopars4ever]what year truck



95 Ram 1500,5.9 2wd.

The rollover valve is designed to keep fuel from leaking into the evaporative emission system if the truck is upside down. I'm not sure about your truck specifically but everything else I've ever worked on doesn't have any control of the fuel pump from the rollover valve.

Yes, you are on the right track, but I know them as a rollover switch and you should be able to reset it.

*Edit* Just looking through my service manual for an '01 Ram, check your ASD automatic shutdown relay.

Does the 95 ram has this? I'm new to this electronic stuff.

Have a look in your power distribution center, that's where it should be if you have one. Will be labeled on the inside lid which one it is.

It says in my service manual it will shut power off to everything, and that kinda sounds like what's happening to you.

I was trying to check spark at the plug but I need another set of hand for that,Lol....my thinking is the same as you it's late I'm going in and getting some rest and try again tomorrow................Thaxs for the help I'll keep you posted what I find.

well I did a test on the relays(ASD/fuel pump)all check out good, but wasn't able to get voltage at terminal 86 in the power command center with the key in the run position. Maybe that was due to the battery running low but I notice that when I check a sparkplug with a plug checker there was no fire so this is were I'm at now NO SPARK.


The manual states that the ASD will deenergize the fuel pump if there's no spark. So the plan tomorrow is to diagnose the problem of no fire.

Can you hear the fuel pump when you turn the key to "run" but not the "start" position?

You had no issues before replacing the fuel pump?

actually I took the new pump out thinking it's bad, but before removing it from the tank I decided to run 12 volts to the pump while still in the tank and was able to drian bout 10-12 gallons from the tank into a drum so I figure the pump was good. Did a relay(fuel,ASD) check all was good so now i'm chasseing a no-spark ing. problem. According to the service manual no-spark, no-fire to the pump.

Yeah, the order that manual is telling you seems backward to me. I'd think you have to have the fuel pump going full circuit and fill the lines before spark can be delivered in the "start" position.

Sorry, that's all I got. Update us when you get it lit, I might run into the same thing on mine someday and would like to know where to look.

Thaxs..........will do, I'll keep you posted

Actually, when you turn the key to the on/crank, the fuel pump gets a 5 second fuel pump cycle from the computer. The computer needs to "see" fuel pressure (fuel pressure regulator). After those first 5 seconds, if the computer does not "see" spark (dist pickup or cam sensor), does not "see" the motor is turning (dist pickup or crank sensor), "see" the motor has oil pressure (oil pressure switch), does not "see" the throttle position (throttle position sensor), (I think there is another thing the computer needs to "see" as well, but it escapes me right now) it will turn off the power to the fuel pump, through the ASD (Automatic Shut Down) relay, and then as you continue to crank it, it won't see fuel pressure and will shut down the spark. Are we having fun yet?

The sensors and the wiring to them are the only way the computer can "see" if the things are functioning. Any bad sensor, any bad wire leading to the sensor, or any bad wire from the sensor to the computer, or a bad circuit through the computer will kill the power to the ASD.

The place to start is to determine if there is power going to the sensors from the ignition switch. Your book will tell you how to check, and how much voltage needs to be at each sensor.

After being sure there is power to the sensors, you need to be sure the sensors are functioning so the power can pass through them. Your book should tell you how to test each of the sensors.

Then you need to check to see if the power from the sensors is getting to the computer. Your book should tell you which wires going into the computer are from which sensor, and how much voltage is suppose to present.

You can't do this without a book/resource. You can't test things out of order, you can't skip a test, and you need to know how much voltage is present at which point, you can't just check it with a test light, unless of course, you don't want accurate results. Gene

Well I think I've found the problem on this truck, seems I got an broken wire on the crankshaft sensor. I'll purchase a new one tomorrow and we shall see...................Thax for the replies Gents

Update........got the truck running found out I had several issues with this truck first the crank senor (which had a broken wire)then I've had issues with an ground on the fuel pump connector seems to have a broken ground wire in the harness that connects from the fuel pump back up to were it connects under the left front fender. This truck has been good to me for the 17 years I've had it, never had to replace any part on it but the water pump/radiator other then that all was GOOD

Did an search on these rollover valves and found that Chrysler did a recall on these trucks for the rollover valves, to the ones that had these change out what did Chrysler replace these with? A better built vale or what?...........Thax.