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Ask Ted Ritter Your Own Question
Ted Ritter
Ted Ritter, Toyota Master Tech
Category: Toyota
Satisfied Customers: 4182
Experience:  Toyota Master Tech, ASE Certified
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Ted we have a 98 toyota Rav4 when we turn the ignition

Customer Question

Hi Ted we have a 98 toyota Rav4 when we turn the ignition switch on with a jumper at the relay circuit by drivers side left knee we hear the fuel pump go on (whizzing) but when we try to start the car it jumps and backfires very hard. Any ideas?
Submitted: 1 year ago.
Category: Toyota
Expert:  Ted Ritter replied 1 year ago.

Hello, thanks for the request

That sounds like it may the the circuit opening relay you are jumping, without the jumper in and the relay installed what does the engine do when trying to start? Can you upload a picture of the relay?

Expert:  Ted Ritter replied 1 year ago.

Is it a 4 cylinder or V6?

Customer: replied 1 year ago.
Ok I'll get a picture but without the jumper there's no power to the fuel pump and it backfires and jumps violently it's a 4 cylinder
Expert:  Ted Ritter replied 1 year ago.

Thanks, ***** ***** a mistake reading the year model, thinking it was an 2008, the picture would be great.

So jumping the relay makes no difference?

Customer: replied 1 year ago.
If we jump it down on the relay near the drivers side knee we hear the fuel pump turn on other than that the fuel pump will have no power and the car jumps and backfires. We did replace the fuel pump and the relay under the dash
Expert:  Ted Ritter replied 1 year ago.

OK, do you have a volt/ohm meter handy?

Customer: replied 1 year ago.
Expert:  Ted Ritter replied 1 year ago.

Check the EFI fuse under the hood, should be hot at all times, check the 7.5A ign fuse on the inside fuse panel with key on. Remove the EFI relay, there should be power to two of the terminals in the fuse block.

Customer: replied 1 year ago.
Ok
Expert:  Ted Ritter replied 1 year ago.

Standing by.

Expert:  Ted Ritter replied 1 year ago.

Hello, I may have to be offline for a while, if all those check out, put the relays back in, access the fuel pump through the rear seat access cover, remove the seat bottom and the metal cover, there is a blue wire and a white black one, the blue is power to the pump and the other is ground, connect a voltmeter to the blue wire and ground the the meter, when turning the key to start and while cranking there should be 12 volts reading at the blue wire, if this the case the fuel pump needs to be replaced.

Customer: replied 1 year ago.
Ok but we replaced the fuel pump because we thought that was the problem, however the car still won't start
Expert:  Ted Ritter replied 1 year ago.

All right, so we can assume that no power is getting to the fuel pump, what were the results of the tests of the EFI relay terminals and the fuse etc.?

Expert:  Ted Ritter replied 1 year ago.

The relay that you jumped does it have 4 prongs or 5?

Customer: replied 1 year ago.
It has 5 they're still doing the volt ohm testing
Customer: replied 1 year ago.
They're thinking it's the crank sensor what do you think?
Expert:  Ted Ritter replied 1 year ago.

Ok, that is the circuit opening relay which is activated through the EFI fuse and the EFI relay, both of those must supply a signal voltage to the C/open relay as well as a starter signal from the ECM and a couple of other signals like rpm and spark confirmation before it will let the fuel pump run, the C/Open relay is not the problem since you already tried a new one, this is why I needed to know if the voltages at the EFI fuses and the efi relay sockets are good. The crank position sensor is a possibility, is there a diagnostic code for it? Did anyone check for diagnostic codes? I didn't realize that the car was being looked at by a shop.

Customer: replied 1 year ago.
My son is actually looking at it he went to get a code reader from his friends shop he's taking forever
Expert:  Ted Ritter replied 1 year ago.

Ok, just let me know what the code numbers are, if any and we'll go from there, I may be offline, just post the results and I'll get back as soon as I can, thanks.

Customer: replied 1 year ago.
Ok thank you so much
Expert:  Ted Ritter replied 1 year ago.

I"m back online, let me know when you have an update for me.

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