Please help w/SC400 won't start

[808SC4]

OK here it goes, about 4 months ago the problem started with it feeling like my fuel was cutting out while i was driving but the car would still run. Then the car started dying out, i would pull over and try and start it. It would turn over for like 2 seconds then die again. After about 2-10 tries it would start and run fine. The problem progressevly got worse, then one day it would'nt start at all and all i did was loosen fuel line from FPR and started the car and shut it off. The car ran fine for about 3 weeks then the same problem came back. I was totally convinced that it was a fuel problem. This is where it gets funny, i started tapping the FPR with a wrench and the car would start. that seemed to always get the car started so i assumed the FPR was no good. After purchasing one from the dealer here in Hawaii for just about 200 dollars the car still did'nt start. The next day i went outside to uninstall the new FPR and the car started and ran fine, so i left it in. I drove the car around all day problem free. The next morning the car would not evan start. So i took the new FPR out and tried somthing else. I changed the fuel filter and the fuel pump, that only seemed to work for about a day or so until the problem came back. The last thing i have tried was bypassing the fuel pump ECU and that worked for about another day until it craped out on me again. I really don't know what to do already at this point. Oh yeah i've also cleaned the idle control motor, and i've changed plugs,wires,caps, and rotors. So can someone Please help me, i would really appreciate it...thanx in advance,Vince

 

[Nick M]

Pull DTC's and see if any come up.

 

[Lextreme II]

Becareful for excessive starting. You might shorten the life of the starter.

 

[808SC4]

update

update: i have changed the ECU and the crank angle sensor and the problem is still happening....please if anyone has any idea what this could be i would greatly appreciate it. i have spent way too much money and way too much time on this...someone help me, PLEASE...thanx

 

[Asrcarbonsc]

maybe it has nothing to do with your fuel, Maybr its your idle air control valve or mass air flow sensor that make u feel ike ur running lean

 

[Lextreme II]

maybe it has nothing to do with your fuel, Maybr its your idle air control valve or mass air flow sensor that make u feel ike ur running lean

You can unplug the maf or the isc the car still start but idle very rough.

MAF Faulty: You can start the car but non responsive
ISC Faulty: You can start the car but it wont hold idle.

 

[Lextreme II]

Make sure when u key on. You should get the P (park) indicator light. If you dont, then the circuit is not complete. If you dont see P, use your left hand to push or pull the shifter until u see it. Then start the car will hold the shifter to P.

 

[4runnin]

I would be checking for a blockage in the fuel return line as if this is blocked it would slowly build up pressure to the point of the FPR not doing it's job and the pressure at the fuel rails maybe much higher than it is supposed to be hence the engine is flooding when the injectors open when starting the engine (flooding even more when engine is cold due to cold start injector) when you disconnect hose from FPR the pressure gets release and takes a day to build up enough to stop the car starting again.


just one of many possibilities

John
'84' 4.0l quad cam toyota 4Runner

 

[boydfoose]

Maybe a problem to the fuel line, should check for clogs or any dirt within the system, ECU's are programmed should not be a problem looking for the right codes

 

[sideshow]

spray sheit down the throttlebody
if it starts better then its fuel related
put fuel press gauge and see if its low
instead of throwing money away check basics first
sometimes its cheaper to take it to an expert
i told a customer today who wanted help over the phone
look at it this way
can u afford to spend a week or 3 trying to sort it out
or is it better to send it to me to hopefully fix in a day

anyway ive had sc400s have problems starting and sometimes cutting out when u hit 5 or 6 miles per hour
check the connectings to engine relays and power to ecu if the fuel pressure is ok