AE111 can crank but engine start

[Lawcc]

Thanks for the info. You DIY?

 

[me2kimi]

Yes, DIY it bro.
One more thing, have you check Circuit Open Relay? This relay is the controller for the fuel pump. Usually this relay locate underneath dashbord.

Sent from my Galaxy Nexus

 

[Lawcc]

Yes, DIY it bro.
One more thing, have you check Circuit Open Relay? This relay is the controller for the fuel pump. Usually this relay locate underneath dashbord.

Sent from my Galaxy Nexus

Thanks for highlighting....
Will the relay cause intermittent issue?

 

[me2kimi]

Thanks for highlighting....
Will the relay cause intermittent issue?

I'm not sure. Maybe yes or maybe no. But you can try swap it first.


Here is how the Circuit Opening Relay operate:


Circuit Opening Relay Function
The function of the COR is to switch power to the fuel pump when the engine is running or being started. Having power to the fuel pump only when the engine is being started or is running is a safety feature.

An example of an event in which the COR would disconnect power to the fuel pump would be an accident, where
The driver is unconscious (and hence the ignition has been left on)
The engine has stalled
The fuel line has been ruptured

In this scenario the COR will be controlled to turn the fuel pump off (as the engine is not running) and this will stop fuel from leaking at high pressure from the ruptured fuel line. This is a desirable (and legally required) safety feature that would not exist if the fuel pump was wired to come on directly with the ignition.

Circuit Opening Relay Operation
The COR is much like a normal relay, however it has two 'triggers', either of which can be used to turn the COR on and switch power to the fuel pump.

Circuit Opening Relay Trigger 1
In all cases one of the triggers to turn the COR relay on is the ignition key being in the START position, this ensures that the fuel pump runs when attempting to start the engine is

Circuit Opening Relay Trigger 2 - Flap Type Air Flow Meter Equipped Engines
In cars with a flap type Air Flow Meter (AFM) there is switch inside the AFM that is open when the engine is stopped, when the engine is running the movement of the AFM flap causes this switch to close and trigger the COR on.

When the engine is not running the AFM switch is open and the COR is off causing the fuel pump to be turned off.

Circuit Opening Relay Trigger 2 - MAP Sensor & Non Flap Type Air Flow Meter Equipped Engines
In cars without flap type AFMs the engine ECU detects the engine speed (via the distributor or crank angle sensor etc) and the engine ECU has a dedicated output pin FC that is connected to ground inside the engine ECU via a transistor to turn the COR on when the engine ECU determines that the engine is running.

When the engine ECU determines that the engine is not running the engine ECU FC output is turned off which causes the COR to turn off and the fuel pump to be turned off.

Summary:
-fuel pump will operate when it detect engine speed
-it also act as safety relay

 

[Lawcc]

WOW...so informative. Thanks a lot.

Do you roughly how much is a COR?

 

[Lawcc]

Yesterday morning the car failed to start again. 2 hours later it could start again.
This morning failed to start again. As at now, it remain unable to start.

Mecahinc said not due to relay, (with the separate cable he had directed from fuel pump to fuse box) the car would still be able to start should the relay gone faulty

 

[me2kimi]

Hmm..quite complicated bro. IMHO, basically there is 3 things engine need to run
1-fuel
2-spark
3-compression
got those things engine can run already.

But it also happened to me twice, suddenly can't start. Got fuel, spark and compression but still not able to start. Cranked it until battery drained. Became fed up that day.
A day after without doing anything than jump battery, the engine can be start. It really stranged.

Better send your car to expereinced foreman.

 

[Lawcc]

As about 8pm, it can start again with just one crank.

 

[Lawcc]

I am actually in the dilemma. Whether this issue is due to mechanical or wiring problem.

Today sent my car to another mechanic, he advised me to send to wiring man (as I told him I have a wireman contact) as he think is more of wiring issue.

Went to wireman shop (recommended by a kind forumer). As the car still can start, it is hard to diagnose. The wireman said most likely is due to fuel pump.

He need more time to diagnose and advise me to leave the car overnight. I couldn't agree as I need the car tomorrow. When I am about to leave, the car cannot be started again.

Within a minute, he detected the wiring at the fuel pump is loose. Within another minute, the wiring secured and car can be started.

Hope this nightmare is resolved once and for all, after torturing me for about 4 months.

 

[AE!!!925]

hello bro,my ae111 got the exact same problem as yours...so does the problem still exist after that?

 

[Lawcc]

The issue never occur since then.

 

[AE!!!925]

ok,i'll try to check mine .THANK YOU once again!!

 

[AE!!!925]

problem solved...its the bad condenser inside the distributor..