MR2 was running fine, replaced battery, now cranks but won't start

As the title says, my AW11 was running fine but the battery was pretty old so I replaced it. When I first tried to start up with the new battery, I got a "click" and everything went dead. Checked the terminals and they weren't as tight as they could be, so I tightened them up and tried again -- now it cranks but never catches.

I figured I blew something, so I replaced the EFI relay and checked all the fuses... Everything looks good now but still no start. Any thoughts on what I should check next?

Any fusible links at the battery cable end?  Confused the security system? Knocked a small ground wire off?

Spark or fuel. Figure our what is lacking and go from there 

Is the battery hooked up backwards?

Battery is hooked up the right way round (I did check to be sure).

If it were a fusible link at the battery, wouldn't all electrics be down?

Spark or fuel -- That's what I've been thinking. What's the simplest test to do on my own? I don't have anyone around today to crank it while I check a plug. Can I spray some starter fluid in the cylinders and try to start? If it begins to catch that way, that would mean I'm getting spark right?

saruken said:

I don't have anyone around today to crank it while I check a plug.

Remove a  plug (or use a spare one) holding it in a jumper cable clip, ground the other end of the cable.  Now you can sit behind the wheel and see the plug or just take it with you.

Working alone makes you cleverer.....

In reply to 914Driver :

Nice! I will try that tomorrow.

Starter fluid anywhere in the intake tract is the easiest way to diagnose whether there is a lack of fuel. 

We fried a computer on the Supra once just changing the battery.

racerdave600 said:

We fried a computer on the Supra once just changing the battery.

Yikes 0.o

I just want it to be anything other than the fuel pump. I don't have access to a garage right now, so that would be a heck of a parking lot repair. It rained today, but tomorrow I'm gonna try both the spark plug on a jumper cable trick, and starter fluid.

saruken said:

racerdave600 said:

We fried a computer on the Supra once just changing the battery.

Yikes 0.o

I just want it to be anything other than the fuel pump. I don't have access to a garage right now, so that would be a heck of a parking lot repair. It rained today, but tomorrow I'm gonna try both the spark plug on a jumper cable trick, and starter fluid.

I've replaced a couple of AW11 fuel pumps, you do want anything other than that, anything!  It seems like such a simple task...

If it's a fuel pump you can always cut an access hole.  It's a bitch on aw11 dropping the tank.

Results are in: spark is good, car wants to start with starter fluid. So... bad news. Fuel isn't getting to the cylinders.

I know the relays and fuses in the engine compartment are all good too. I checked the ECU's self-diagnostic codes, and it didn't throw anything. Just a single flash to indicate "normal" condition -- That means the ECU isn't fried right?

So how else can I prove it's not the pump? Because I'm still refusing to believe that right now...

You need to check for fuel pressure.

https://www.toyotaguru.us/mr2-mk1-1989-aw11-repair/check-fuel-pressure-1.html

You can also get or make an adapter that temporarily replaces the banjo bolt holding the fuel line to the rail, then put your pressure gauge on that.  That's what I did when running down problems on an AW11.  It had 4 extra valves, though. 

Oh, and check for +12v on the fuel pump pin at the diagnostic connector when you stick a screw driver into the AFM to hold the flapper open.

You should also check the BGB on the diagnostics- shorting (I think) B+ and fP in the port with a paperclip runs the fuel pump without the ECU, which can be heard by taking the fuel cap off and putting your ear to it.

GIRTHQUAKE said:

You should also check the BGB on the diagnostics- shorting (I think) B+ and fP in the port with a paperclip runs the fuel pump without the ECU, which can be heard by taking the fuel cap off and putting your ear to it.

I could also hear this when the ignition is first engaged right? If I got someone to put it in "on" while I was listening?

Actually sounds to me like an old wiring issue. Can you get access to the starter? Maybe take the starter off and check it is still good. I think it was my 89 Merkur XR4Ti I had to run new wire to  the starter for ground and positive.

Then it fired with the pre battery change gusto.

saruken said:

GIRTHQUAKE said:

You should also check the BGB on the diagnostics- shorting (I think) B+ and fP in the port with a paperclip runs the fuel pump without the ECU, which can be heard by taking the fuel cap off and putting your ear to it.

I could also hear this when the ignition is first engaged right? If I got someone to put it in "on" while I was listening?

Yes.