theroots

I have a 1JZGTE in my Lexus SC300. The first time that I try to start the car each day, it starts and idles fine but only for between 20 seconds to a minute or so. Then it immediately dies. Afterwards, when you try to start it, the starter spins and might occasionally stumble, but it won't start. I've measured the fuel pump at prime, and it's only getting around 10 Volts. When the car is trying to start, it drops to around 9.5V. I always assumed that fuel pumps where designed to receive 12V at prime. The previous owner replaced the fuel pump and the filter, but I am certain that what I am experiencing is an electrical issue. The battery is fine, as it starts my AE86 flawlessly. The previous owner suggested that after pulling the spark plugs the plug closest to the firewall was soaked in gas, but the other five were dry. It's curious, because when the car is running, it runs very well.

I am going to try to see if the car will run on starting fluid after it dies, but where should I look next?

Thanks for your help!

soarer13oy

iTrader: (13)

Is the diagnostics box wired into the harness? You can try jumping pins b+ and fp and start it to see if it stays on.

theroots

Will this ensure that the fuel pump has 12V?

sfgsdfg999

iTrader: (1)

was the 12v mod done to the fuel pump?

theroots

No, the 12V mod hasn't been done to this car.

sfgsdfg999

iTrader: (1)

What pump is in there now? I gathered an upgraded pump and constant 12v was needed. No code 14? - my JZA70 1J ,95 SC300 gave me code 14. The IGF signal wasn't being read by the ECU so the computer shut off the injectors and would die and then finally didn't start at all, bad ECU. Open the ECU (take ESD precautions) and look at your caps. Got spark, got fuel, got air. If you now someone that you can swap an ECU temporarily temporarily... I had to get another ECU.

theroots

The car has a walbro 255, and the ECU was sent to DriftMotion two months ago to have the caps replaced. However, they don't test the ECUs after they replace the caps, so there's no guarantee that it's any good. I have a JZA70 ECU, and I don't know anyone that has one locally. I'm in the process of trying to buy one on ebay, so we'll have to wait and see about that. The car does run on starting fluid. What happened to you sfgsdfg999 sounds similar to what's happening to me.

I'll keep you all updated.

sfgsdfg999

iTrader: (1)

when I opened my ECU my caps looked fine so something else was messed up. I'm saving for an AEM standalone so I don't have to worry about this again (am going single in the future anyway). Thanks to my FPR, Boost, Volt and AFR gauges I can rule out a lot of stuff. My current ECU has an MREL fault which keeps my fuel pump running after I turn it off - otherwise runs awesome. Had to wire a switch to kill it after taking the key out, 25 year old elec ghosts.....

theroots

It ended up being the ECU, like I sort of suspected. Although the car starts every time now, it generally only starts with a little bit of throttle input. It's also not idling a little low and not idling up at cold start. However, it runs and drives like a top. As soon as I get the chance, I'm going to clean the IAC and go from there. Thanks for all of your help!