Assistance needed !!! 5A-FE

[Japan_fan]

Greetings all...
I currently own an AE110 with a fuel injected 5A engine.
2 weeks ago there was a problem when I attempted to start the vehicle to leave my workplace to head home.
The car would tumble strong, and eventually after numerous attempts along with flooring the gas pedal it will eventually start.
I have since scanned the vehicle (OBD 1) and the only issue that can up was the water temperature sensor.

The water temperature along with the fuel regulator, fuel pump, TPS have been changed as well as the throttle and the injectors have been cleaned. However the problem still exists.

It would seem that this only happens on a cold start, for when u do get the car started and then switch it off it will start back immediately. But once it's parked for a while it will give trouble to start.

Another diagnostic scan revealed no errors.

Does anyone have an idea of what I should check next ?
Any assistance/advice on the matter would be greatly appreciated.

Thanks

[anthonemorris]

Alright. So its not fuel delivery, or spark. Have u checked airflow? Make sure the maf is working (cleaned).

[Japan_fan]

This engine is MAP sensor not MAF. But I was thinking along that same line.

[toyolink]

A blown cylinder head gasket could also account for problem.
Since you picked up an error code which informed water temp sens.,the question has to be asked ;
Have you at any time had a 'overheating' episode?

[Japan_fan]

Car kinda overheated once about a year ago, wasn't actually a over heat, radiator burst, rolled back to the station and fixed it there. didn't really cross the usual temperature reading as the wind got to hit the car back to the station. Changed radiator and car has worked great since.

[anthonemorris]

might be a stretch but check fuel pressure. may be that the pump is showing signs of wear and isn't pushing the needed fuel pressure. as i said its a stretch but can still check it

[Japan_fan]

Well I thought along the same line and I changed the pump but problem still persists. Gonna check to see if an injector is leaking when the car is off thus releasing the pressure when at rest

[anthonemorris]

any luck?

[Japan_fan]

No luck. Don't know what to do next

[Japan_fan]

Any more advice / suggestions? I'm open to anything

[Japan_fan]

Changed injectors..still no luck

[anthonemorris]

Have u checked the throttle body?

[toyolink]

I have encountered a similar problem which eventually got to the point where the vehicle would stall.
What was found; the ecu/brain box needed to have simple components replaced.
Apparently,these control modules maintain a very simple board which develop a 'cold solder' condition as well as deterioration of resistors.
Take the ecu to a proper auto electronic service provider and have same examined/cleaned-up.

[wanted]

I had that same problem with my 110 and after many checks the problem was bad distributor . Changed it and car working good!

[Japan_fan]

Toyolink..any recommendations as to whom I can carry my ecu to have it checked/ repaired?

[Japan_fan]

Wanted...I thought along the lines of the distributor but wasn't sure, thought that if it was a problem with the distributor it would occur all the time and not just on a cold start.

[Japan_fan]

By the way the throttle was thoroughly cleaned as well as air filter and fuel filter changed. They were due so I changed them one time

[anthonemorris]

I have an ecu for the old model 5a if it works that way. Pm me

[YelloRolla]

hey bro,have you tried a compression test ?

[Japan_fan]

No I haven't. What kinda values am I looking for ?

[YelloRolla]

5a fe engines usually read about 200 psi per cylinder....

[Japan_fan]

Cool I will look into that this evening

[Hook]

I'm thinking either low compression or a fuel rail issue (not holding fuel pressure in the rail overnight).

Since it overheated recently, have a leak-down test and a compression test done to properly evaluate the situation with your cylinders. If your mechanic can put a fuel pressure gauge on it and look at the pressure drop when you switch off, that may be useful as well.

[Japan_fan]

I'm attempting to get a fuel gauge hooked up but it's a lil tricky as the the line from the filter to the rail is a banjo bolt on either end. Doubt it's the rail as I changed the rail twice already. Still got to do the compression test as well

[YelloRolla]

As I said before, do the compression test, it will give you a gud idea of the condition of the engine on the inside....its the first test I do when a customer has problems such as yours8-)

[Japan_fan]

Ok people so here is an update. Short version of this update is....I fiddled with some wires under the dash near the brain...and what do u know...car starts like its brand spanking new. So I'm looking for a good Electrican to maybe check the wires from the temp sensor to the brain and see maybe if it's shorting

I would also like to thank all u guys for all the help thus far. It's greatly appreciated

[Japan_fan]

So since my last post here, the problem persisted, so while I was attempting to find a reliable electrican to test my theory of having a short in the wiring, I decided to get the timing belt changed as it was overdue. Since changing the timing belt, car works like a dream. It's been almost two weeks since changing and I haven't had any hard starting issues. Thought I'd share. Btw the timing belt that was taken out looks to be in pretty good shape.maybe it was stretched? Thanks again for all the input/replies thus far

[anthonemorris]

Interesting fix. Still trying to figure out if it was timing off or just tension. Thanks for sharing though