Intermittent Start Issue (Parking The Car Under Sun Too Long)

shanakamm · November 5, 2014

Hi Guys

I’m facing this weird starting issue in my Toyota AE110 Sprinter. When I leave the car under the sun for too long, it doesn't want to start until the sun goes down or the car cools. If I park in the shade there isn't usually a problem. I have no problems starting the car in the evenings or first thing in the morning. somehow this happens when the car interior is very hot. usually with closed windows.

sometimes car will start after 5-6 attempts and stops after few seconds. can smell the petrol and the sound is not like usual. sounds is like it doesn’t like to start at all. No engine warning light appears.

one mechanic said to me it was due to bad distributer coil, but I didn’t buy it cause car is perfectly running in traffic in very hot daytime. when its starts it won’t give any issues. running perfectly. i have done below things recently.

Toyota AE110 Sprinter 1997 - A/T

186K Mileage

Engine and ATF oil changed recently

Engine tune-up done recently (Cleaned TB, changed spark plugs and Air filter)

No warnings lights or any other electrical issues

No mechanical or performance issues (10-11 kmpl in Colombo)

I’m assuming this is due to some sensors/computer box issue with the heat. (Computer box located inside the car under the AC Unit/evaporator). really appreciate your help on this.

Thanks

Davy · November 5, 2014

Does the starter motor crank the engine or is it just a clicking or dead motor when hot?

My guess is that it's a connection issue somewhere. Most probably with a relay that refuses to switch on when hot. When the car refuses to start, open the bonnet and open the fuse box in the engine bay. Ask someone to start the car while you gently tap on the ignition relay (identified by a "key" symbol on the fuse box).

The Don · November 5, 2014

Davy sounds like the car cranks but doesn't start .....................

This is usually a fuel delivery problem (vaccume leak, fuel pump issue or blocked lines), since the engine is hot the engine being under compression (not usually this noticable in petrol vehicles) or an electronic issue (need to scan to find out).

shanakamm · November 5, 2014

Does the starter motor crank the engine or is it just a clicking or dead motor when hot?
My guess is that it's a connection issue somewhere. Most probably with a relay that refuses to switch on when hot. When the car refuses to start, open the bonnet and open the fuse box in the engine bay. Ask someone to start the car while you gently tap on the ignition relay (identified by a "key" symbol on the fuse box).

Thanks for the quick reply Davy . its cranking. and sometimes after 5-6 attempts engine starts. but like i said it will stop after few seconds. if i press the accelerator the engine wont respond to it. wont accelerate. sometimes engine sound like backfire. (not too hard/loud though). and the engine is vibrating/shaking during that few seconds and then stops. and the petrol smell. guess it’s because of the unburned fuel from tail pipe.

I will check relays and fuses as you mentioned and see any changes. But my concern is this is not happening while driving the car in traffic. Which is much hotter inside the engine bay than under the sun.

Edited November 5, 2014 by shanakamm

The Don · November 5, 2014

Thanks for the quick reply Davy . its cranking. and sometimes after 5-6 attempts engine starts. but like i said it will stop after few seconds. if i press the accelerator the engine wont respond to it. wont accelerate. sometimes engine sound like backfire. (not too hard/loud though). and the engine is vibrating/shaking during that few seconds and then stops. and the petrol smell. guess it’s because of the unburned fuel from tail pipe.
I will check relays and fuses as you mentioned and see any changes. But my concern is this is not happening while driving the car in traffic. Which is much hotter inside the engine bay than under the sun.

Could be your ignition system (ignition wires, electronic control or coil packs). Might be worth while scanning it and seeing if it indicates the problem.

shanakamm · November 5, 2014

Davy sounds like the car cranks but doesn't start .....................
This is usually a fuel delivery problem (vaccume leak, fuel pump issue or blocked lines), since the engine is hot the engine being under compression (not usually this noticable in petrol vehicles) or an electronic issue (need to scan to find out).

Could be your ignition system (ignition wires, electronic control or coil packs). Might be worth while scanning it and seeing if it indicates the problem.

already scan the car Don. no engine issues or warnings found. (This is OBD I) , and the 'check engine' light didnt came up during the starting attempts . Can this be the Distributor (capacitors and Coils) ? and how to check that ?

Edited November 5, 2014 by shanakamm

The Don · November 5, 2014

already scan the car Don. no engine issues or warnings found. (This is OBD I) , and the 'check engine' light didnt came up during the starting attempts . Can this be the Distributor (capacitors and Coils) ? and how to check that ?

The issue you have is its intermittent, else this could have been very easily found.

The key to finding out is reproducing the issue under controlled environment like at the garage. Then you can check if each cylinder is getting a spark. There are plenty of videos on youtube which explain how you can test a coil or coil packs. Check the wires also and the connections into the distributor if your coil packs are centrally located (not attached to the plug directly).

Davy · November 5, 2014

Looks like my previous guess is not a possibility, given the fact that the car sometimes starts and even manages to stay going with a bit of stepping on the accelerator. As The Don has said, the next thing to check is the ignition system. If you're can manage to check if each cylinder gets a spark when the car wouldn't start, it will be much easier to narrow down the actual problem.

Ignition systems do tend to fail when hot, but what's puzzling about the situation here is that the car is drivable even when the engine is hot.

shanakamm · November 7, 2014

I will check all 4 spark plug this weekend and let u know the results.. Thanks

shanakamm · November 8, 2014

Is it possible to start the car without any issue or any warning lights after removing Engine Main Relay ???. cause i just unplugged the engine main relay and tried to start. car started as usual. is this means its not working already??

Davy · November 8, 2014

Is it possible to start the car without any issue or any warning lights after removing Engine Main Relay ???. cause i just unplugged the engine main relay and tried to start. car started as usual. is this means its not working already??

You mean your car started without the main relay in place? That's impossible (unless someone has rewired your car bypassing the main relay somehow)!. The main relay usually controls the fuel pump, and injectors without it your car is going nowhere.

Wondering now whether my initial guess above is right. I had a similar experience with one of my old cars and it was a relay that had gone bad and stopped switching on when hot.

Edited November 8, 2014 by Davy

shanakamm · November 9, 2014

Yes Davy. started without main relay. heres my observations

Removed Engine Main Relay - Car started as usual, can hear fuel pump working for 3 secs before the start

Removed EFI/F-HTR Relay - No start. Crank only.

Removed Starter Rely - No Crank, No Start. can hear fuel pump working continuously.

so its seems like main relay is not working and bypassed somehow as you said. didnt have a chance to replicate my original issue. but im thinking i might need to check this relay problem 1st. i heard that toyota corolla and sprinters have separate fuel pump relay under the dash and tend go bad in hot conditions. but not sure if this model has a one or its exact location. if so its fits the symptoms, cause im facing this issue when the cars interior is hot and not having any problems while driving the car. (i always driving A/C ON). any ideas ???

Edited November 9, 2014 by shanakamm

Davy · November 10, 2014

Not sure what's up with your main relay, but I think you should first try to sort out your original issue.

To confirm whether it's the fuel pump relay, you need to park your car in the sun and bring it to a point where it doesn't start. When this happens, switch on the car and check if the fuel pump is operating. The pump should be located underneath the back seat. Placing your palm over the pump will tell you if it's working. If it's not, then it could be that the fuel pump relay is at fault. If the relay is inside the car as you say, then this may very well be the issue.

Watchman · November 12, 2014

My first bet is a fuel pump issue that Davy's describing.

My 2nd bet is a busted set of valves that arent sitting right. Hence till the engine heats up a bit (and the valve rods expand), there isnt enough compression building up for it to run on its own.

The Don · November 12, 2014

There is another way to isolate the issue to the fuel pump. I do not know if you get this in SL, but there is this spray called "cold start" which is basically an inflamable solution which you spray into the instake to get a non starting car to start. In SL people use a bit of petrol into the carb or throttle body, but this is a little safer. If you spray into the intake (you have to take the air filter off and spray into the air intake tube) and the car starts normally, but doesn't without the spray, its definitely an issue with the fuel pump.

You can of course use davy's method as well, but sometimes the issue is the fuel pump works, but is not delivering enough fuel due to a partial failure. Another way to check it is to take the petrol line off the fuel rail and take a fuel can, or a bucket and let the line rest inside the bucket so any fuel that comes out can be collected without spillage which can be dangerous. Then turn the ignition key to the on position, and fuel should come gushing out of the intake line (you can turn it to off position straight away if this happens). If it doesn't well.... the fuel pump has kicked the bucket.

Davy · November 12, 2014

Once my uncle's car died suddenly (in Melbourne) and I was with him at the time. After about 15 minutes of trying to get the car to start, he called his breakdown service. The guy turned up and the first thing he did was try to jump start. Then he took a small bottle with a pointed neck (bit like a silicone tube) filled with petrol, took off the PCV tube and asked me to start the car while he squirted some petrol into the PCV tube towards the intake manifold. The engine sputtered back to life (so it was a fuel pump issue which was sorted out later). I thought to myself that day what an innovative way that was to get some petrol into the cylinders without having to remove the air filters and stuff.

As for the fuel pump testing method suggested above by me, it can only be used to get to know whether the pump is getting power or not. Should be quite helpful to OP.

The Don · November 12, 2014

Once my uncle's car died suddenly (in Melbourne) and I was with him at the time. After about 15 minutes of trying to get the car to start, he called his breakdown service. The guy turned up and the first thing he did was try to jump start. Then he took a small bottle with a pointed neck (bit like a silicone tube) filled with petrol, took off the PCV tube and asked me to start the car while he squirted some petrol into the PCV tube towards the intake manifold. The engine sputtered back to life (so it was a fuel pump issue which was sorted out later). I thought to myself that day what an innovative way that was to get some petrol into the cylinders without having to remove the air filters and stuff.
As for the fuel pump testing method suggested above by me, it can only be used to get to know whether the pump is getting power or not. Should be quite helpful to OP.

Clearly the Aussie break down guys are a bit more innovative than ours, but these cold start sprays are off the shelf products and freely available

Your method works fine Davy, and even I use it, and in my case I kind of listen out and know when the fuel pump is on (it makes a distinctive hum). Listening out does not work if the sound insulation in your car is really good, or the pump is near silent.

Not all cars give you access to the fuel pump from inside the car though (its a really silly thing really) and require the fuel tank itself to be dropped down, as was the case with a 2003 Ford focus of a friend which suffered fuel pump failure due to the car not being used for over a year.

aps · November 14, 2014

check ur car injector seals,

btw how long you can run without main relay ?

shanakamm · November 16, 2014

Its very hard to replicate the issue in this rainy weather .

check ur car injector seals,
btw how long you can run without main relay ?

Injectors and seals are good. Tune up done recently.

Its been 3 years since i bought this car. used daily without any problems. so im not sure it is re wired to separate relay in somewhare else in the car.