Hi,

My car is acting a little strange and I'm trying to figure out the cheapest fix.

I have a Toyota crown with an efi engine conversion and I modified the fuel tank with an in tank walbro fuel pump. The car drives perfectly well, but when I first start the car at idle I can hear the frequency of the fuel pump straining, almost as if there is not enough power to it. Then when you let the clutch out and start driving, the headlights dip, fuel pump frequency drops significantly and the whole car kinda of strains because the electrical system is not supplying enough power. I know the wiring is sufficient gauge to the fuel pump and it's not an individual fuel pump issue, its power to the whole car. The battery appears to work fine because it starts first time, every time. The battery terminals are good quality, and the grounds on the car are good. It has the stock 55 or 60 amp alternator and the car idles about 1000 rpm.

 

I'm wonder whether I need to be get a bigger battery, or would poor output from the alternator cause this.

Cheers

Check the amperage output of the alty. They are better than generators at low revs, but still have a lower output at lower revs.

Ask an auto electrician or a battery shop to put an ammeter over it and check the voltage regulation.  As you say, its a lack of power to the whole car & the fuel pump noise is just a symptom.

How long ago did the EFI conversion get done ?  Did you do it, or was it done by others ?  Did this "power issue" occur directly after the EFI conversion, or was there a long period where it ran perfectly with EFI, without this "power" issue, & then it just appeared out of the blue.

What fuel delivery system was there before you fitted the Walbro electric in-tank pump ?  Why was there a need to change to the Walbro ?

Did this "power issue" only occur straight after you did the Walbro in tank pump conversion ?

Sometimes the back ground to these problems, can point you in the right direction, to what is the cause, & where to look.

Cheers Banjo

First Step is to confirm your alternator works, Put a multi meter on the battery and let us know what it says with the engine off, engine at idle and engine at 4000rpm.

 

thanks for the responses, iv been a bit swamped, ill check out those things and report back.

 

cheers

ought new battery after last new battery died after 2 weeks of being connected only drove a little bit each week, new battery won't charge at all on old alternator so I bought a new and it had 3 terminals when the plug has 2. Either I rebuild the old one, see if it works or ʞ©$ɟ around with the new one. Can the voltage regulator if faulty, stop the alternator from charging? A lot of questions I know! I'm new to this please help