AE86 Rough Start up

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

AE86 Rough Start up

Postby Swooki » Sat Jan 18, 2020 5:01 pm

I have a GTS 85 AE86, and whenever i start it, the car will crank a few times and struggle to start and will start but while it is cranking and starting the check engine light is flashing. After started, the car runs perfectly fine.
What could be the issue? why does it have a hard time starting and check engine light is flashing?
Please help.
Car runs fine when started.. just starting it has its issues. not smooth like other ae86s i have driven.

Disable adblock

This site is supported by ads and donations.
If you see this text you are blocking our ads.
Please consider a Donation to support the site.


User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Sun Jan 19, 2020 1:46 am

Does it still blow a cloud of white smoke when you start it up in the morning ?

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Sun Jan 19, 2020 5:52 pm

jondee86 wrote:Does it still blow a cloud of white smoke when you start it up in the morning ?

Cheers... jondee86


What do you mean blow a white cloud of smoke? like condensation?

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Sun Jan 19, 2020 6:40 pm

Sorry... got my posts mixed up :?

Is the battery getting weak... cranks slow until it catches ? Easy way to check is
to jump start your car using another car with a good battery as a booster. If the
engine starts easily without struggling then your battery needs load testing to see
if it is still up to the job.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Disable adblock

This site is supported by ads and donations.
If you see this text you are blocking our ads.
Please consider a Donation to support the site.


Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Mon Jan 20, 2020 10:16 pm

jondee86 wrote:Sorry... got my posts mixed up :?

Is the battery getting weak... cranks slow until it catches ? Easy way to check is
to jump start your car using another car with a good battery as a booster. If the
engine starts easily without struggling then your battery needs load testing to see
if it is still up to the job.

Cheers... jondee86


Brand new battery voltage 12.6 bought on 11/19. :( So i'm not sure what's wrong..
Any other ideas?..
someone told me cold start injector but im not sure where it is or if its true..

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Tue Jan 21, 2020 12:15 am

Cold start injector does not affect how fast the engine cranks. But if it is not
working it will affect how long the engine has to crank at normal speed before
it catches.

If you have a timing light you could check the ignition timing while the engine
is warmed up and idling. You should have around 16-17deg BTDC (reading from
the scale on the lower timing belt cover). Too much ignition advance will cause
the engine to struggle when cranking and even stop dead or kick back.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Wed Jan 22, 2020 2:16 pm

jondee86 wrote:Cold start injector does not affect how fast the engine cranks. But if it is not
working it will affect how long the engine has to crank at normal speed before
it catches.

If you have a timing light you could check the ignition timing while the engine
is warmed up and idling. You should have around 16-17deg BTDC (reading from
the scale on the lower timing belt cover). Too much ignition advance will cause
the engine to struggle when cranking and even stop dead or kick back.

Cheers... jondee86


so when it starts, it catches but struggles (with check engine flashing) then it starts up and runs perfect.

i'll look for timing..

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Wed Jan 22, 2020 11:47 pm

Any chance you could post a video of the car starting up ? Right from the
moment you switch the ignition ON and hit the starter would be great. Just
a vid of the tacho with the sound of the engine so we can hear/see what
you are hearing and seeing :)

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Davegt27
Club4AG Enthusiast
Posts: 94
Joined: Thu Jan 10, 2013 10:35 pm
Location: co

Re: AE86 Rough Start up

Postby Davegt27 » Thu Jan 23, 2020 2:09 am

Go for the easy fix first

Check grounds (that means clean grounds, take the ground wire and bend them back and forth to break up any internal corrosion)
Then reattach
Davegt27 Code One Racing

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Fri Jan 24, 2020 9:38 pm

Davegt27 wrote:Go for the easy fix first

Check grounds (that means clean grounds, take the ground wire and bend them back and forth to break up any internal corrosion)
Then reattach



which grounds are there that i can check..?

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Fri Jan 24, 2020 9:40 pm

jondee86 wrote:Any chance you could post a video of the car starting up ? Right from the
moment you switch the ignition ON and hit the starter would be great. Just
a vid of the tacho with the sound of the engine so we can hear/see what
you are hearing and seeing :)

Cheers... jondee86


Hello! I have a video.
https://streamable.com/yldo0

So in this video, it starts then idles super low before it catches..

Usually, it struggles like this and goes up but then drops almost to 0 and goes back up again.. then idles normal.

What could cause this?

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Sat Jan 25, 2020 12:44 am

Cranking speed sounds about normal to me. If you were to turn the engine off
straight after it started to run clean and smooth, and then start it again, would
it still struggle and shake, or would it start up like normal ?

I'm wondering if it is getting enough fuel for the first crank. If you have a fuel
pump test plug, try jumping the plug and turning the key to the ON position...
wait a few seconds (you should hear the pump running) and then crank the engine.
See if that makes a difference.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

totta crolla
Club4AG Pro
Posts: 528
Joined: Tue Mar 26, 2013 5:21 am
Location: Oxford U.K

Re: AE86 Rough Start up

Postby totta crolla » Sat Jan 25, 2020 10:38 am

It sounds like it is over fuelling but I'm not sure that there is an error code for that when the engine is first started as the O2 sensor is not reporting. Have you checked for stored error codes? Maybe try disconnecting the cold start injector to see if there is a difference?

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Sat Jan 25, 2020 10:46 am

jondee86 wrote:Cranking speed sounds about normal to me. If you were to turn the engine off
straight after it started to run clean and smooth, and then start it again, would
it still struggle and shake, or would it start up like normal ?

I'm wondering if it is getting enough fuel for the first crank. If you have a fuel
pump test plug, try jumping the plug and turning the key to the ON position...
wait a few seconds (you should hear the pump running) and then crank the engine.
See if that makes a difference.

Cheers... jondee86


If i start it again after shutting off, it would start up like normal (confirmed yesterday 1 try only though)

I don't have a fuel pump test plug nor know what it is, and don't know how to jump the plug either :(..

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Sat Jan 25, 2020 10:47 am

totta crolla wrote:It sounds like it is over fuelling but I'm not sure that there is an error code for that when the engine is first started as the O2 sensor is not reporting. Have you checked for stored error codes? Maybe try disconnecting the cold start injector to see if there is a difference?


I can check if there are stored codes...

Where is the cold start injector located?? sorry i am not very mechanically inclined..

totta crolla
Club4AG Pro
Posts: 528
Joined: Tue Mar 26, 2013 5:21 am
Location: Oxford U.K

Re: AE86 Rough Start up

Postby totta crolla » Sat Jan 25, 2020 11:17 am


User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Sat Jan 25, 2020 12:10 pm

https://www.club4ag.com/forums/viewtopic.php?t=11360

If you can find the "T" shaped plug, use a short piece of wire or even a bare metal
paperclip as a "jumper" to short or temporarily connect the two pins on the plug. Turn
the key ON while the pins are connected and you should hear the fuel pump run. Let the
pump run for 3 or 4 seconds. Pull the jumper wire out and then crank the engine... it
should start normally.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Sat Jan 25, 2020 2:17 pm

totta crolla wrote:23260 on this diagram. http://auto-kat.com/index.php?route=sal ... group=2211


Disconnected it and it still started rough.
I put a paper clip into diagnostic port and it did not flash codes, the light was solid.

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Sat Jan 25, 2020 2:19 pm

jondee86 wrote:https://www.club4ag.com/forums/viewtopic.php?t=11360

If you can find the "T" shaped plug, use a short piece of wire or even a bare metal
paperclip as a "jumper" to short or temporarily connect the two pins on the plug. Turn
the key ON while the pins are connected and you should hear the fuel pump run. Let the
pump run for 3 or 4 seconds. Pull the jumper wire out and then crank the engine... it
should start normally.

Cheers... jondee86


Hey, https://ibb.co/ZJrRF7V < photo
Followed these steps and saw the T shape plug and put a paper clip in and i couldn't hear the fuel pump run... but i let it sit for 3-4 seconds and disconnected it and it still started super rough. what do you think? (This time it started and will idle at 100 RPM for like 1.5 seconds before going up.)

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Sat Jan 25, 2020 4:17 pm

OK... we need to figure a way to get the fuel pump to run for a couple of seconds
before you try and start the engine. If shorting the FP test plug didn't work ( and it
should have) there is another way. You need to take the airfilter off your AFM (Air
Flow Meter) and while the key is ON, push the flap inside open an inch or so. This
should start the fuel pump and if it doesn't, get someone else to push the flap open
while you go round to the trunk and listen. It will not be very loud but there should
be a small whirring sound as the pump does its stuff.

Then, once the pump has run (how long does not matter but three seconds should
be enough) crank the engine as usual.

The object of this testing is to see if you are getting fuel draining back to the tank
overnite due to the check valve in the pump not holding pressure or some other
freak condition. If the car stuggles the first time but fires right up the second time
you start it, air in the fuel line would explain the difficult first start.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Swooki
Club4AG Enthusiast
Posts: 86
Joined: Wed Dec 21, 2016 1:48 pm

Re: AE86 Rough Start up

Postby Swooki » Sat Jan 25, 2020 9:44 pm

jondee86 wrote:OK... we need to figure a way to get the fuel pump to run for a couple of seconds
before you try and start the engine. If shorting the FP test plug didn't work ( and it
should have) there is another way. You need to take the airfilter off your AFM (Air
Flow Meter) and while the key is ON, push the flap inside open an inch or so. This
should start the fuel pump and if it doesn't, get someone else to push the flap open
while you go round to the trunk and listen. It will not be very loud but there should
be a small whirring sound as the pump does its stuff.

Then, once the pump has run (how long does not matter but three seconds should
be enough) crank the engine as usual.

The object of this testing is to see if you are getting fuel draining back to the tank
overnite due to the check valve in the pump not holding pressure or some other
freak condition. If the car stuggles the first time but fires right up the second time
you start it, air in the fuel line would explain the difficult first start.

Cheers... jondee86


https://streamable.com/wt2a2
Here's a new video.

So i noticed even if i start the car and then letting it run for 30 seconds or anything and i shut it off and try to start it again, it'll still struggle to turn on like this.

I will try the fuel pump tests again..

What would the solution be you think?

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Sat Jan 25, 2020 11:24 pm

This is a tricky one :? And because the problem only exists for a second or so when
starting, not easy to diagnose. I'm leaning towards a fuel supply problem but it could
also be an electrical supply problem. It's almost as if the car first starts on two cylinders
and then all four kick in and away she goes.

The flickering of the check engine light could indicate that the ECU loses power for a
moment when you crank. As soon as you let go of the key power comes back and the
engine catches and runs just when it is milliseconds away from stalling. To prove or
disprove this theory means monitoring the voltage of the power supply to the ECU
during cranking. If it drops down to 4 or %V during cranking, that's your problem.

Perhaps a first step would be to check the temperature of all the relays in the underhood
fusebox after the car has been running for a while. See if any one of them is getting
unusually hot to touch. You could also pull (extract) and then replace each relay and fuse in
the fusebox just to break up any surface corrosion that might be causing high resistance.

Also while you are under the hood loosen off all the ground straps and battery clamps,
give them a good twist from side to side to make sure they have a clean contact, and
then tighten. And (this is important) check that the ECU grounds (several brown wires
connected to a single brass ring connector) are bolted down,

Image

These are located on the intake side of the engine near the back and on top of the intake
manifold. The ring connector is usually bolted down under the bracket that holds the
wiring harness in place.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

totta crolla
Club4AG Pro
Posts: 528
Joined: Tue Mar 26, 2013 5:21 am
Location: Oxford U.K

Re: AE86 Rough Start up

Postby totta crolla » Sun Jan 26, 2020 2:40 am

With the diagnostic port shorted you should get a steady flashing of the engine management light (EML) on the dashboard, it should not be on solid. Jondee will chime in I'm sure but l think this could be a TPS problem where the idle switch is not engaged in the TPS, effectively the ecu looks at the wrong part of its calibration when starting. The solid EML is a clue to this.
Which engine do you have, 20v 16v MAP or AFM?

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Mon Jan 27, 2020 5:16 pm

I believe I have these correctly identified...

Image

... but by all means tell me if I am wrong so that I can change the diagram :)

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

totta crolla
Club4AG Pro
Posts: 528
Joined: Tue Mar 26, 2013 5:21 am
Location: Oxford U.K

Re: AE86 Rough Start up

Postby totta crolla » Tue Jan 28, 2020 1:18 am

Yes Jondee those are correct.

User avatar
jondee86
Moderator
Posts: 2540
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: AE86 Rough Start up

Postby jondee86 » Wed Jan 29, 2020 12:27 pm

totta crolla wrote:With the diagnostic port shorted you should get a steady flashing of the engine
management light (EML) on the dashboard, it should not be on solid. J?

Chances are the ECU was not in diagnostic mode... https://ibb.co/ZJrRF7V

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

totta crolla
Club4AG Pro
Posts: 528
Joined: Tue Mar 26, 2013 5:21 am
Location: Oxford U.K

Re: AE86 Rough Start up

Postby totta crolla » Wed Jan 29, 2020 1:57 pm

jondee86 wrote:
totta crolla wrote:With the diagnostic port shorted you should get a steady flashing of the engine
management light (EML) on the dashboard, it should not be on solid. J?

Chances are the ECU was not in diagnostic mode... https://ibb.co/ZJrRF7V

Cheers... jondee86


Oh... that'll do it :shock:

Disable adblock

This site is supported by ads and donations.
If you see this text you are blocking our ads.
Please consider a Donation to support the site.



Return to “TECH: 4A-GE ENGINE”

Who is online

Users browsing this forum: No registered users and 2 guests