Whats the fuel setup like?
Alright here's my specs...
Smallport 4AGE in an E7 Corolla, engine is EFI, running a cut and shut smallport intake manifold with a blocked off cold start and it's completely stock.
Here's my problem, it's hard to start firstly but I attribute this to the blocked off cold start valve, basically you start it and unless you keep he revs over 2 grand it'll just stall, it takes a little over 5 minutes for it to idle normally but I usually just get it out of my driveway and once I'm driving it's fine.
Anyway most of the time the engine runs perfectly fine, healthy power, doesn't stall, no hesitation but randomly at anytime the engine will just start stalling, so for example you're coming up to a red light and you engage the clutch to change from 3rd to 2nd, the car will stall unless you give it some throttle in between changes but it will restart once you disengage the clutch (like a roll start), 2nd to 1st car will stall, disengage clutch car will fire up again, you can't sit at the lights idling either it'll just stall.
Also randomly and at anytime I'll return to the car after an hour or so of doing whatever and it just won't start, takes ages and heaps of cranking to get it fired up, sometimes it won't even fire up at all, had to get a tow last week.
I've had two Toyota, electric and generally all-round good people with engines check it over and they've been stumped. Sometimes it's perfectly fine other times it's not. Generally if I leave it for a few days it'll start up fine no worries.
I'm a patient kind of dude but this is really starting to piss me off, I'm contemplating just giving up on it all together, no one can diagnose the problem and these guys are pretty fucking good with engines, especially Toyotas. So does anyone have any idea what it could be?
Whats the fuel setup like?
Undercar surge with some sort of intank pump feeding the surge, then a Walbro EFI pump, not sure what kind, marginally smaller than an 044.
Man, with stuff like this, I could write a lot soo I'll try to keep it short.
How low is your idle? Is the timing set properly? Are you running factory dash pot? Do smallports even run a dashpot?
Aside from the obvious, When it doesn't start next, can you pull the return line off the rail and see if it has fuel? Then test the spark with a spark tester, not just confirming spark with a spark plug jammed into the lead earthing on the block. Having spark doesn't mean it's enough to start the engine, it has to be strong.
If the obvious spark and fuel are there then disconnect all the unnecessary sensors around the engine. I doubt it's the problem but it might tell you something.
The other thing is it might be (and probably is) the distributor. Try swapping another distributor in there.
Last and most annoying thing is the wiring loom. When the car's running all good, shove the loom around in various places and see if it causes any of the problems you have.
That should keep you busy for a while.
The timing is set fine, the idle is set fine, I'm getting fuel at the rail, I've tried three distributors, I've tested the spark and it was fine but I think the issue might be spark related. I've had two good mechanic/auto sparkies look over it and check all that sort of stuff and they were stumped, all that kind of stuff has been checked.
I'm gonna drive it until it happens with my old man driving behind me with a car full of parts and tools. Will report back to thread.
Last edited by KurtHS; 24th October 2011 at 01:12 PM.
Could be something as wak as the board in the ECU is damaged.
Once it heats up or gets bumped around it causes an open circuit and prevents starting......
I was thinking this might be the case, so I'm looking for another ecu.
Of course they do!..
Why has no-one suggested setting the TPS?
i think this mans on the money^^^^^^^^^
Unset tps wouldn't show intermittent symptoms like this car. and if it was tps he woulda found it when he disconnects all the sensors except cas and map.
with stuff like this you can't really diagnose on the internet unless it's a real common problem. You're gonna have to find the problem on the side of the road yourself, or just replace everything that can fail and hope it goes away.