Engine starting problem

Badmoon

Member +
Hi everyone!
I'm having an odd problem since the last time I rebuilt my engine.
I start the car, everything okay, drive the car for a while and park it. If I try to start the car again, say after 15/30 minutes from being parked, I doesn't want to start again unless I give it some pedal gas. I tried to adjust the idle screw in the TB to compensate this but if I do the idle RPM is just too high with the engine cold and also hot, so this isn't the right procedure to address the problem.
Have already checked all my vaccum lines and no leaks too. My coolant sensor is a new original part. I also have a new O2 sensor which I didn't install yet, it's a Bosch LS 01 which is supposed to be a compatible replacement for this engine. Could the O2 sensor be the problem or it doesn't play a part in this?
Please help me with your experience in this matter as I can't find the reason why this is happening, doesn't bother me too much but I would like to get this fixed.
Thanks in advance!
 

SKINY

Lifer
I ran mine daily 2 years with the O2 sensor disconnected and didn't cause that issue bud, its common enough and the answer is on here somewhere I just can't think at the moment :)
 

Badmoon

Member +
Have you checked the condition of your battery, starter motor and alternator?
The battery is around 6 months old, never failed so far and is reading 12,64 volts at the moment. The starter motor also never failed to spin and is very lively. The alternator, if it wasn't working properly, the battery wouldn't charge and I would have noticed not charging the battery by having low power in it or failing to start the car, it never occured.
When the problem happens all these components seem to be in top working order, battery does not fail and starter motor spins at its top speed, just the engine doesn't start until I press the accelerator pedal a bit.
If you think this problem could be related to one of these parts please tell me how I can troubleshoot them.
If needed I can record a video of the problem I mention as soon as I have a run in the car and park it for awhile.
 

Badmoon

Member +
I ran mine daily 2 years with the O2 sensor disconnected and didn't cause that issue bud, its common enough and the answer is on here somewhere I just can't think at the moment :)
So the O2 sensor can't possibly be the cause for this problem.
Thanks for your input!
 
check the 3 main points of reference for start ups. doubt the 02 would be the issue as the starlets stock run a closed and open loop detection.

Check Sensors. ie (electrical) coolant sensor green, tps, and iACV, then Ignition stuff, spark plugs, leads, distributor, and king coil pack. and lastly Fuel related, fuel filter, fuel pump.
 

Badmoon

Member +
check the 3 main points of reference for start ups. doubt the 02 would be the issue as the starlets stock run a closed and open loop detection.

Check Sensors. ie (electrical) coolant sensor green, tps, and iACV, then Ignition stuff, spark plugs, leads, distributor, and king coil pack. and lastly Fuel related, fuel filter, fuel pump.
The coolant sensor is a brand new original Toyota, the old one was working but I bought a new one just to be sure and nothing changed.
I don't know what I should look in the TPS as it was calibrated one time already.
The iACV you talk about is it the idle control valve? If it is then it was already opened up and cleaned. Nothing changed.
Spark plugs are 6 months old NGK BKR7E.
Leads are stock, tested their resistence and are all within minimal specs but waiting to get new Magnecor ones.
Distributor has new rotor and cap.
Also don't think its a problem from the king coil pack but how should I test it? I was having ignition problems but as soon as I swapped the old rotor and distributor cap it was okay again.
Fuel filter was also changed 6 months ago.
I already had a fuel pump problem last year and swapped for a Celica one (made a great difference from the tired stock one which was still working), maybe I'll buy a Walbro in the near future.

Another thing my car is a 4efte swapped Corolla E11. Could the original fuel regulator play some part in this problem too?

Appreciate your help buddy!

Edit: Actually the spark plugs are NGK BCPR7ES and I also have a new set of NGK Iridium BKR6EIX which I never used because of its heat range.
 
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The coolant sensor is a brand new original Toyota, the old one was working but I bought a new one just to be sure and nothing changed.
I don't know what I should look in the TPS as it was calibrated one time already.
The iACV you talk about is it the idle control valve? If it is then it was already opened up and cleaned. Nothing changed.
Spark plugs are 6 months old NGK BKR7E.
Leads are stock, tested their resistence and are all within minimal specs but waiting to get new Magnecor ones.
Distributor has new rotor and cap.
Also don't think its a problem from the king coil pack but how should I test it? I was having ignition problems but as soon as I swapped the old rotor and distributor cap it was okay again.
Fuel filter was also changed 6 months ago.
I already had a fuel pump problem last year and swapped for a Celica one (made a great difference from the tired stock one which was still working), maybe I'll buy a Walbro in the near future.

Another thing my car is a 4efte swapped Corolla E11. Could the original fuel regulator play some part in this problem too?

Appreciate your help buddy!
yes the iacv is the idle control.

starlets use 3 versions to maintain harmonic idle regardless of temperature.
#1 a Throttle screw which is a governed leak, RPMwise, out for higher, in for lower.

#2 a Throttle Stop screw, this can be set to allow or disallow air leakage, normally not overly used. and if wrong will mess with things. in the case of aftermarket ECU use, this can be used to idle the car.

#3 the iDle Air Control Valve, An in out Air cycle Actuator, very primitive in how it works and incredibly prone to failure.

the bottom of the throttle body has a second stage of Air leakage. For help in using the throttle Screw.
this is controlled via a small thermostat which when heated with the engines coolant will reinforce the amount of air allowed to leak out. if yours is dead this "could" be your issue. remove it, dissasemble it, and clean accordingly.
 

Badmoon

Member +
yes the iacv is the idle control.

starlets use 3 versions to maintain harmonic idle regardless of temperature.
#1 a Throttle screw which is a governed leak, RPMwise, out for higher, in for lower.

#2 a Throttle Stop screw, this can be set to allow or disallow air leakage, normally not overly used. and if wrong will mess with things. in the case of aftermarket ECU use, this can be used to idle the car.

#3 the iDle Air Control Valve, An in out Air cycle Actuator, very primitive in how it works and incredibly prone to failure.

the bottom of the throttle body has a second stage of Air leakage. For help in using the throttle Screw.
this is controlled via a small thermostat which when heated with the engines coolant will reinforce the amount of air allowed to leak out. if yours is dead this "could" be your issue. remove it, dissasemble it, and clean accordingly.
So, first the throttle screw, I already tried with this one and the problem can be eliminated with it but in the other hand the idle RPM is too high both in cold or hot engine situations, so not the way to go for solving this problem.
Second, the throttle stop screw you mention, never heard of this and don't know where it is located. Can you please help me with this one? I'm also using a Blitz ECU, could this be related to the problem? As I did a lot of work in the car and the ECU was one of the parts changed it can be the link to this. What do you think?
Third the idle air control valve, as I said it was opened and cleaned, what I can say is that before the procedure and after I didn't notice any difference both in idling or starting the engine cold or hot, everything remained the same.
Now that bottom of the throttle body you say, is it that part where some pipes connect to? Didn't want to be messing with that thing for now only after all other possibilities are exhausted.

Thanks again!
 
From what you say, the iacv is for now, not the issue :)
srdglkgr.JPG
So, first the throttle screw, I already tried with this one and the problem can be eliminated with it but in the other hand the idle RPM is too high both in cold or hot engine situations, so not the way to go for solving this problem.
Second, the throttle stop screw you mention, never heard of this and don't know where it is located. Can you please help me with this one? I'm also using a Blitz ECU, could this be related to the problem? As I did a lot of work in the car and the ECU was one of the parts changed it can be the link to this. What do you think?
Third the idle air control valve, as I said it was opened and cleaned, what I can say is that before the procedure and after I didn't notice any difference both in idling or starting the engine cold or hot, everything remained the same.
Now that bottom of the throttle body you say, is it that part where some pipes connect to? Didn't want to be messing with that thing for now only after all other possibilities are exhausted.

Thanks again!
The image above. 4e throttle body. red part us your throttle stop screw. well the backside of it anyway.


So, first the throttle screw, I already tried with this one and the problem can be eliminated with it but in the other hand the idle RPM is too high both in cold or hot engine situations, so not the way to go for solving this problem.
THIS is your issue. that narrows it down hugely. someones messed with the idle gear. maybe it came loose, or maybe someone bumped them. they can even IDLE loose.

adjust the rpm so the issue goes away as you did before. then check to see if the throttle blade IS fully closed, by removing the intake intercooler charge pipe. ( this will make your car Non turbo temporarily, so be careful. if so, and the issue is resolved, good. at this point you can mess around with said screws to allow for the idle to be "set" you need around 900 warm. any higher and the car will quite literally drive itself. any lower and the cars gonna hate you when cold.




the blue marked section refers to the thermostat, it can be serviced two ways. removed entirely OR the bottom part removed and checked.
be warned, if the seal is gone on the whole assy, you cant get another. you will have to make it.
 

Badmoon

Member +
From what you say, the iacv is for now, not the issue :)
View attachment 9061

The image above. 4e throttle body. red part us your throttle stop screw. well the backside of it anyway.



THIS is your issue. that narrows it down hugely. someones messed with the idle gear. maybe it came loose, or maybe someone bumped them. they can even IDLE loose.

adjust the rpm so the issue goes away as you did before. then check to see if the throttle blade IS fully closed, by removing the intake intercooler charge pipe. ( this will make your car Non turbo temporarily, so be careful. if so, and the issue is resolved, good. at this point you can mess around with said screws to allow for the idle to be "set" you need around 900 warm. any higher and the car will quite literally drive itself. any lower and the cars gonna hate you when cold.




the blue marked section refers to the thermostat, it can be serviced two ways. removed entirely OR the bottom part removed and checked.
be warned, if the seal is gone on the whole assy, you cant get another. you will have to make it.
Have checked the throttle stop screw and it seems to have never been touched only the top screw on the throttle body been used as I also did.
As for the adjustment you mention I have another problem... My RPM counter doesn't work very good it's always going up and down since I did the swap so I can't be really sure what RPM is the engine at for this procedure. And what should I do if the throttle blade is not fully closed after I adjust the throttle idle screw to the point the engine starts after being hot?

Thanks!
 
Have checked the throttle stop screw and it seems to have never been touched only the top screw on the throttle body been used as I also did.
As for the adjustment you mention I have another problem... My RPM counter doesn't work very good it's always going up and down since I did the swap so I can't be really sure what RPM is the engine at for this procedure. And what should I do if the throttle blade is not fully closed after I adjust the throttle idle screw to the point the engine starts after being hot?

Thanks!
on a stock engine, you ideally wish the throttle blade to rest Fully closed, using the throttle blade Stop screw. one a modded ecu, this can be a little annoying, especially with haltech gear. my rpm jumped all over the place.

To See your Main idle settings. simply start the car, cold or not, and see what she rests at, take note of this rpm number if the car is cold.

wait until the car warms up, and again, take note of the number, these 2 numbers are your "sweep" as the idle adjuster works by adjusting a zone of available air restriction. the amount is normally the same based on 4efte engines anyway. This will Always be a compromise, most opt for a slightly worse cold start, to achieve a very stable Warm condition idle


What tends to occur is the main idle screw has no real way of being "held" in place. often loosening and resulting in the issues you seem to have.
the smallest change will make the car upset. especially as the TPS, and Throttle stop are all preset to the old adjustments.

i had this issue. and i solved it. personally i had a tiny amount of sealant in the idle screw hole once it was adjusted perfect to hold it.
 

Badmoon

Member +
on a stock engine, you ideally wish the throttle blade to rest Fully closed, using the throttle blade Stop screw. one a modded ecu, this can be a little annoying, especially with haltech gear. my rpm jumped all over the place.

To See your Main idle settings. simply start the car, cold or not, and see what she rests at, take note of this rpm number if the car is cold.

wait until the car warms up, and again, take note of the number, these 2 numbers are your "sweep" as the idle adjuster works by adjusting a zone of available air restriction. the amount is normally the same based on 4efte engines anyway. This will Always be a compromise, most opt for a slightly worse cold start, to achieve a very stable Warm condition idle


What tends to occur is the main idle screw has no real way of being "held" in place. often loosening and resulting in the issues you seem to have.
the smallest change will make the car upset. especially as the TPS, and Throttle stop are all preset to the old adjustments.

i had this issue. and i solved it. personally i had a tiny amount of sealant in the idle screw hole once it was adjusted perfect to hold it.
The RPM problem I have is because my old engine used coils not a distributor, I always had this since I swapped to the 4efte and the ECU had no affect to this matter as I used the stock one, the stock with an HKS PFC F-CON and now a preprogrammed Blitz ECU, the RPM not being steady was always the same with any of these combinations.
 

SKINY

Lifer
Right, so.......
Finally remembered where I've came across this before
Head has been melted lately, apologies :)
On the older celicas we came across this issue with hot staring, it was narrowed down to old wiring between the ecu and the fuel pump relay with the wire basically being old and shit and dropping current, try a jumper wire from as far as long as you can to the relay. There is a "relay fix kit" for the celicas and seeing they are so similar in wiring respects I'd say it's doing the same ? Hmmmm
 

Badmoon

Member +
Right, so.......
Finally remembered where I've came across this before
Head has been melted lately, apologies :)
On the older celicas we came across this issue with hot staring, it was narrowed down to old wiring between the ecu and the fuel pump relay with the wire basically being old and shit and dropping current, try a jumper wire from as far as long as you can to the relay. There is a "relay fix kit" for the celicas and seeing they are so similar in wiring respects I'd say it's doing the same ? Hmmmm
No need to apoligize mate!
That's definitely something to be checked. I also noticed fuses inside the box that had better days... Maybe it's time to change some if not all of them. Tried to unplug the big EFI one and it broke.
Thanks for the suggestion!
 

Badmoon

Member +
Hi!
Sorry to bring up this thread again but today I found a broken wire in the TPS connector which I believe is either the one that goes to the Ecu IDL or PSW, its the bottom one if seen connected to the TPS.
Tomorrow I'm going to the mechanic and try to fix it. Let's hope the problem is really this!
 

Badmoon

Member +
Try a wee jumper wire on it 1st Bud, save time that needs spent on it :)
Don't have time to do it today I'm with my daughter. I already had scheduled to go to the mechanic tomorrow morning as my new set of tyres arrived friday so this will get fixed too.
 

Badmoon

Member +
Broken wire in the TPS plug fixed, also had a broken wire in the ICV plug, the 12v one, both fixed, what are the chances of it being both related to the car idling...
Anyway, the idling got better overall, I can hear the ICV ticking not a very loud noise, but the problem for which I created this thread is not... With the engine cold it starts up right away, with the engine hot also starts up right away but after being stoped around 15 or 20 minutes and I try to start the engine it cranks many times until finally it fires up, usually I press the gas pedal a bit because I don't like to force the starter motor so much.
So any more tips for this specific problem?
Also noticed that my thermostat (a bit more then 1 year old, around 5000kms on it) is stuck open as my temperatures take longer to rise and while cruising they drop significantly, with the lower temperatures felt around here latelly its more visible droping between 50 and 60 degrees while going down a mountain road for example. My mechanic said that it isn't that bad being stuck open and if he was in my place he would just take it out, stuck closed is much worse. I think I'm going to get a new one and change it when is time for the new timing belt and water pump in around 2000kms.What are your opinions on this matter?

P.S. - I didn't open and clean the waxstat yet, didn't really want to be messing with that thing but if anyone says it MUST be related to it, as a last resort I might do it.
P.S. 2 - This problem really doesn't bother me that much but if I can get rid of it I will.
P.S. 3 - A few weeks back I also noticed that some coolant has been thrown out from the overflow bottle, I topped out the radiator and it keeps throwing it out to a level where it just stays there and doesn't go down more then that, so I just keep watching the water level in the radiator to be sure it is at the same level before driving the car. I think it may have started when the thermostat seized.

Thanks to all of you!
 
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