Why won't it start
 

We replaced the fuel pump, and the starter. Still starts when it wants to. 1991 4runner. Also bought a new battery. Alternator is ok. It seems like it's something between the ignition and the battery in the wiring?! We're about to go crazy trying to figure it out. The wires are like a bunch of spaghetti. I really appreciate if anyone has any suggestions. Thanks a bunch, Christy


Also, we found a sending unit unattached. Does anyone know where it goes?!

Have you checked for trouble codes ?
Use a short wire , connect terminals TE1 and E1 of the data link connector , turn the key on but don't start. Push the OD button in. Watch the CEL and OD lights.

What sort of sound does it make when it does'nt start ?

Where was the sending unit that you found located ?

It could be the contacts in the ignition switch itself. You can try removing the trim panels from around the steering column to expose the ignition switch and with the doors open and the truck sitting outside for good ventilation, hold a rag or paper towels under the ignition switch, and cover the surrounding areas to protect against overspray and dripping, and hose the ignition switch down with a complete can of CRC QD Electric Parts Cleaner (make sure it's the "QD" type.

Afterwards, while holding the "straw" attachment to/into the keys' slot, lightly spray it with a silicone lube to relubricate it.

Let dry for a sufficient amount of time and see if that solves the problem. :great:

Possible neutral safety switch - probably on the clutch pedal.

Sounds like you're shooting in the dark between electrical and fuel. More details on the problem, please.

There isn't a CEL though

It's got a brand new ignition switch too. Thanks though.

It's an automatic. It usually starts right up in the morning. It seems to be most problematic when it's time to go home from work around 5 PM for some reason. I get a jump and it starts right up.

What EXACTLY is happening when it won't start? Clicking? Cranking? Nothing? Any lights? Weather conditions?

It clicks and all the lights work. Nothing weather related affects anything.

Sounds like something is draining the battery. What is the voltage reading while running? When it is shut off? 8 hours after shut down? Do you have an ammeter?

Sounds like you've got the same problem I used to. Starter would act up when the air temperature was warm. Seems to have been a problem with the wire running to the starter being old & building up resistance. I put in a starter relay using the tips from 4Crawler on THIS PAGE. Go down to the last section on the page. I didn't use any fancy parts - just a 30 amp relay from Radio Shack and some wire and connectors I already had.
Good luck.

I would also look at the starter...after all it is 10 plus years old.......

It's also been determined that a surprisingly small amount of dirt/corrosion where the starter bolts onto the bell housing can cause this problem. Blocks the ground part of the circuit. Something to look at...

Have a look at the web page below for some troubleshooting and repair ideas:

http://www.4crawler.com/4x4/CheapTricks/Starter.shtml

Maybe it's just a matter of a loose connection or two and you need to tighten something down..., or..., you're a "hot" girl and someone at and/or around work has got it hot for you and is shorting your car out so that they can play the "knight in shining armour" (pun intended) routine and come to your rescue so that they'll be able to start up a conversation with you to help them get over their initial shyness??? You never know. :bigok:



p.s. I've got to stop watching those damn cutesy, "girl" flicks!! :laugh: