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View Full Version : E7 4AGE Won't Idle, Not Hunting Or Cold Start



KurtHS
22nd October 2011, 01:33 PM
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?

anastasios
22nd October 2011, 02:22 PM
Whats the fuel setup like?

KurtHS
22nd October 2011, 03:54 PM
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.

Skylar
23rd October 2011, 12:42 AM
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.

KurtHS
24th October 2011, 01:08 PM
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.

slide86
24th October 2011, 02:18 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......

KurtHS
24th October 2011, 04:29 PM
I was thinking this might be the case, so I'm looking for another ecu.

timbo
24th October 2011, 09:57 PM
Do smallports even run a dashpot?

Of course they do!..

Why has no-one suggested setting the TPS?

lolwat
24th October 2011, 10:00 PM
i think this mans on the money^^^^^^^^^

Skylar
25th October 2011, 04:06 AM
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. :DD

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.

lolwat
28th October 2011, 09:25 PM
you need another ECU man??? got 2 bp amd and 3 JDm ones here.. fuck just read small port :(, had any luck at all? have you tried waiting till it starts fucking up (leave it running at home drive around block 400 times) and then checking over everything (cas signal, spark, injector pulse, ECU power blah blah)

claw
28th October 2011, 10:16 PM
reset tps, and also check the plug on the temp sender at the back of the head, mine wasnt running for shit gave it a jiggle, now mint, also, your not starting at all seems like coil power....converted looms like to do that

lolwat
28th October 2011, 10:21 PM
coil power which will be injector power also

claw
28th October 2011, 10:27 PM
not if your running dizzy

lolwat
28th October 2011, 11:01 PM
beleive coil power is black with orange trace and injector power is also the same colour, power the pos side of the coil from the battery and it will power coil and injectors

KurtHS
31st October 2011, 03:36 AM
I'm running a JDM loom though Claw. I've also tried another ecu that came from a running car and no deal.

lolwat
3rd November 2011, 06:26 PM
get it rewired, complete engine loom