Starting Problem

[channingd]

Hello all,

New to the board. Just got myself my favorite truck of all time a 1987 Chevy Short Wide.

This truck has been monkey rigged like any other vehicle of it's age and I'm trying to put her back to her glory days. Fortunately here in New Mexico we don't have to battle the rust problem.

When I got it, the steering column, tilt, was extremely loose, so I took it down to the torxe head screws and tightened them and put it all back together. Column now fixed.

Went to start the truck to move her and she wouldn't start. The first thing I realized was the fuel pump switch, which is now on a toggle had come loose from it's power source so the pump wasn't running. I gave it power temporarily off the radio fuse. Pump is now running when I turn the ignition to on. It was a constant power source before without being keyed. Truck still won't start. Cranks over fine. I then gave it a shot of starter spray down the throttle body. Success. Truck starts fine.

Now truck will not start without prime down the throttle body. Runs fine after I get it started.

Did something possibly get messed with in the steering column or is it possibly the way the fuel pump is jury rigged.

Any help will be listened to.

Thanks,

[tvblazer78]

First thing welcome to the board!

I know that a fuel pump will some on just right before it starts, but it sounds like you need to see what PSI you are getting in your fuel line. It may be low.

Can anyone help him out?

[silvereagle07]

The 87 has an ECM that controls the TBI unit. When starting it energizes the fuel pump relay. The pump should pressurize the system to about 10 psi. When the engine begins turning over the ECM recieves a signal from the distributor telling it to operate the fuel pump. Check for power at the fuel pump relay when you turn the key on. If it has power it will energize and turn the fuel pump on until it gets enough pressure to start. If the pump comes on and it still doesn't start, it may be caused by the distributor. I've had one go bad on my dads truck. Hope this helps.

[silvereagle07]

Oh yeah, I got a rebuilt distributor from Autozone. In stock. I picked up a CHILTONS manual for him also. It has wiring diagrams and explains how the fuel system works, alot better than I can. Good luck and Welcome to the board.

[channingd]

So I finally got some more time to work on her.

With the recommendations you guys posted, I got to thinking it might be something with the ECM so I disconnected the battery and let it reset. I also wired the fuel pump up to a constant 12V source. Started right up no problems.

Again, thanks for the help.

[silvereagle07]

channingd, the fuel pump needs to go through a relay or it will not last long.

[channingd]

Silvereagle,

When you say go through a relay, is that so it gets power only when needed? I'm going to have to buy the manual to get the wiring diagram of the fuel circuit and fix it right.

Right now it's on a toggle switch, so you have to turn it on when you start the truck and remember to turn it off when you shut it off.

Thanks,

[silvereagle07]

channingd the fuel pump relay is used by the ECM to control the on/off of the fuel pump. If is 12v constant it will eventually overheat or cause it to flood if you don't cut it off.

[channingd]

Gotcha,

I will wire it to through the relay as it is supposed to be. Maybe the relay went out so they wired it direct? Cheaper in the short run but pricier in the long.

Thanks again,

Channing