Newb here, needing expert advice. Having problems starting my truck and not sure what the problem is. Driving along normal then engine quits. Start a day later and runs fine. Shut back off then turn back on and it cranks for days. I have read on the Forums that the fuel pump and relay might be the issue, but my trouble is which pump do i need to get? I know i have a 98 50th anniversary truck, but idk if i need an advanced Evaps system or pre Evaps system.

 

Well, you could check fuel PSI on driver side injection rail - 32-34PSI expected. You could have a crank shaft position sensor going bad, but normally it acts up when hot, then restores when cooled off. The VSS switch could also be suspect, it is said they make the OBDII port show way high miles per hour. Could also be electrical connection at pump under carpet in cargo area.

The advanced EVAP system has a rectangular box under the hood, the older system has a round canister.

 

Well to me it feels like my mph is slow rather then fast. Either that or people just drive way faster then me (Yet i am used to driving a compact car). Have tried numerous times to start but nothing. Even though i am not mechanically inclined, ill do what i can.

 

If crank shaft sensor, there won't be any spark.

If vehicle speed sensor, this only applies to driving at moderate speed, won't impact starting.

Fuel pump electrical connections can have a mind of their own. Pump should run for like 2 seconds when key turned to position 2.

 

I was having the same issue. The connector to the fuel pump was not making good contact. I made sure the connector had each of the metal fingers popped out far enough to make good contact, now it starts and runs just fine.

 

There is plenty of spark, that was the first thing i checked. My dad thinks that changing the fuel filter would help, but i doubt that is the issue. Usually when i would start the truck, would have the power on, then a little thud noise, then turn to crank over, Relay kicking in turning the pump on?

 

Inspect the fuel pump harness at the plug at the tank and at the plug at the rear drivers wheel. When a pump goes out it can burn the connector. It will intermittently not start and when you jiggle the connection it will work. Easy enough to change too

 

Fuel filter should be changed anyway, if you have never changed it. You can read fuel PSI before and after change. Use a gauge attached to the "tire valve" on the passenger side fuel rail. Dad is always right. The older you get, the smarter he becomes. Eventually we realize Dad was cool genius. But intermit operation is usually electrical related. The pump draws like five amps, and is routed from the multifunction relay on fender wall and the inertia switch on fire wall. Inertia switch kills pump in a crash, has reset button on top.

 

My father already asked, "Why dont you just change the filter?" Its obvious its not that, but of course i will change it, just need to know what is bad first, only problem is, idk jack about working on these trucks at all, lol. plus with the Rave Manual, idk which relay to check that is on the inner kick panel with those relays, plus dont have the tools to see if the relays are bad or not

 

To DIY you wll need basic tools, plus a meter (under $20). Yes, you can spend more on a meter, and I own a dozen or more. And I have worked with meters that cost more than a Disco. But a basic one will do. Metering skills are rapidly learned.

Please see attached drawing from RAVE. The relay is part of the multi-function one, and is under the hood, between ECU and battery along the passenger fenderwall in a black box. The ECU calls for the relay, which should engaged at position 2 for perhaps 2 seconds. You should hear pump run. You can shake wiring or clean connectors there and in the trunk under the carpet. You can also get at the wire for metering for volts to chassis frame at the inertia switch. Schematics are like an old style road map, the current has to flow along those lines or it can't get there.

And pumps can go bad all by themselves, just trying to point out the cheap to fix issues.