Wierd Electrical Issues on the 77 Celica GT

Well, after towing the car to Atlanta from Miami, replacing the fuel pump, getting a junkyard carburetor from another 20R, pulling the carb to replace a gasket that sprung a leak, pulling the fuel pump to fix some loose wiring, I FINALLY got the car running! It sounds brand new once it warms up, you'd never imagine that it had been used as a shelf in my Grandmother's garage in Miami for almost 10 years .

So, I'm super excited, it's the first time I've heard the car run since I was a wee young lad, and it's the first car I've ever had that had more than ugly mechanical issues when I picked it up. So this morning before work I walk passed it and try to start it... no dice.

To backtrack a bit, I had a buddy of mine who's much more electrically inclined than I over to take a look at it as I wasn't getting any fuel pressure. We tested a few things and kept seeing very intermittent issues. As a quick test, we pulled the fuel pump out, dunked it in a bucket of water and jumped it directly to the battery for a second to see if the problem was the pump. Sure enough it worked just fine. (Yes, I did everything I could to get as much water as possible out of it before putting it back in the tank ;)) Well, through the course of our testing the fuel gauge was showing a level. Once we got the car started, the gauge was reading zero. I didn't really think much until it wouldn't start this morning, but sure enough the gauge was working again. Well, I figured I'd try to test this theory that had been dancing around my head all day and tried unplugging the fuel level sender. I got in, turned the key to on and heard the pump prime. I cranked it and sure enough after a couple seconds, it fired right up.

Though I can't find any schematics (because Chiltons is USELESS! and finding a shop manual for a 77 Toyota Celica is proving harder than I imagined), from what we can tell, the pump and the level sender both have a single wire going into them. I'm assuming they both ground through the shell of the tank, so they share a common ground.

What could be causing only 1 of these to work at a time? The problem seems to be on the sender side, but what could it be? Wire fault? A bad ground from a sender that sat in a tank of 9 year old fuel? Other?

Try the Haynes manual, they are pretty good, keep an eye peeled on e-bay for a toyota shop manual.

http://cgi.ebay.com/Toyota-Celica-1971-1985-Haynes-Repair-Manual_W0QQitemZ130236309067QQihZ003QQcategoryZ378QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

With many old cars, grounds are an issue. You might want to make sure the tank is well grounded (they usually mount on non-conductive padding). Also make sure the battery ground is good. Using a few jumper wires might be a quick check.

good call. Any ideas for properly / easily grounding it out?

Well, I do not know how the tank is attached in a 77 Celica. Hung with straps seems to be the most popular. I would guess taking off one of the straps and wire brushing the tank and strap would be helpful, making sure the strap mount point is also clean.

The battery cable is easy (the cables can get very corroded inside so don't trust the outer appearance), make sure the attach point is clean also.

If you have some jumper cables, you might want to test this by going from the negative terminal to a cleaned spot on the tank and see if everything works.

Well you could ground it like my neibor growing up. He put in a big ass woffer speeaker in the back of he waggon and screwed right in to the gas tank with 4 inch sheet rock screws. When the mech tried to drop the leaks when full tank he removed the sraps but it would not come down....A pry bar finaly striped the screws and down it came.....

Ture story! That guy as a moron. Later that year he hole sawed the brake line making room for another speaker... If you can get to the top of the sending unit drill a 1/8 or 3/16th holes and use a BLIND pop rivet to sercure a ring lug with a 16 gauge wire soldered to it. Many tanks come this way. Blind rivets you don't see the back side of the pop pin. Transmision shops use them on convertors with out drain plugs, but most hardwear stores should have them too.

44

LOL I think that's a no-go on the subwoofer idea. I like for fuel to stay within the tank, or somewhere between the tank / carb ;)

I'll have to have a look and see what can be done, thanks for the suggestions guys :)

Muff-

Have you tried contacting HELM for a shop manual? They ain't cheap, but they're thorough.

You lost me on HELM...?

HELM

Are you going to bring that thing to our night events Andrew?

Patrick

Let's see... 95% prep STS2 miata, or a 0% prep celica with the deadest shocks ever, needs brakes, tires are dry rotted, won't idle when warm........... :p

It's going to be the miata

EDIT: There doesn't seem to be any HELM stuff for toyota... unless I'm not looking in the right place, which I imagine is possible.

You need to join the OCC (Old Celica Club). Google it. I don't know if they have a forum or if it's still Old Skool mailing list, but they will know EVERYTHING about your car.