Hyundai Forums banner
1 - 20 of 23 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
Replaced my 2.0T engine with rebuilt engine. New starter, crank and cam sensors. Keyless start. Have an intermittent rough starting with starting trying to re-engage causing grinding but will fail to start. Happens intermittently. When it starts, engine runs smooth, No failures codes present.
Traced start signal wire to relay when it wont start and the starter signal at the relay is high causing starter to re-engage. Took to Hyundai dealer to diagnose and they are telling me there is some incompatibility with engine and ECM. This makes no sense since it runs fine when it starts.
THinking it may be intermittent issue with ECM.
Looking for other suggestions.
 

·
Registered
Joined
·
3,883 Posts
So this must have a push-button start? Key- only would not try to restart. Did you fail to get this replaced under the lifetime warranty?
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #3 ·
So this must have a push-button start? Key- only would not try to restart. Did you fail to get this replaced under the lifetime warranty?
IT is a push button start, but the button appears to fire the engine every time. Engine has intermittent rough starting with starter grinding and then fails to start. Dont think its the push button start causing this
 

·
Registered
Joined
·
3,883 Posts
Have you had the battery load-tested?
 

·
Registered
Joined
·
2,744 Posts
What brand new starter?
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #9 ·
brought car to hyundai dealer. After 4 days, they gave up and could not find root cause. They are telling me the rebuilt engine may not be compatible to PCM program.. They are runs great once it starts. I asked service manager to give me an example of an incompatibility and he couldn't. Called engine rebuilder and he confirms it if a YF engine. THey provided a long block, i installed everything else from old motor except for new sensors.
 

·
Registered
Joined
·
2,744 Posts
Go to salvage yard and get a used genuine OE starter. Verify that it has a solid internal lever prior to installation.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
18,185 Posts
Traced start signal wire to relay when it wont start and the starter signal at the relay is high causing starter to re-engage.
Have you checked this start signal when the engine is starting normally? Does the power to the relay coil switch off as soon as the engine starts when the starter is working normally?

The high side (positive side) of the relay coil is controlled by the push button module. The low side (ground side) of the relay coil is also controlled, by the engine ECU. I'm just wondering if it's the high side that is causing the starter to reengage, or is it the low side. To figure that out you would need to monitor both the high and low side signals when the engine is starting normally. Then compare the normal signal behaviour to what happens when the fault occurs. Maybe the wire that controls the low side of the relay coil is intermittently shorting to the car body (ground) causing the starter to operate when it shouldn't.

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #14 ·
Have you checked this start signal when the engine is starting normally? Does the power to the relay coil switch off as soon as the engine starts when the starter is working normally?

The high side (positive side) of the relay coil is controlled by the push button module. The low side (ground side) of the relay coil is also controlled, by the engine ECU. I'm just wondering if it's the high side that is causing the starter to reengage, or is it the low side. To figure that out you would need to monitor both the high and low side signals when the engine is starting normally. Then compare the normal signal behaviour to what happens when the fault occurs. Maybe the wire that controls the low side of the relay coil is intermittently shorting to the car body (ground) causing the starter to operate when it shouldn't.

If I helped you fix it, why not...

Your support is greatly appreciated
I think the starter issue is collateral damage. The engine tries to fire and starts stuttering and the high side of the starter is being activated to re-engage since the engine is not fully started. The engine fails to start in this condition. I do smell fuel when this is happening. I at times press the button to stop the engine when its stuttering to avoid flywheel/starter damage.
 

·
Registered
Joined
·
3,883 Posts
Could you have low fuel pressure? HPFP possibly?
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
18,185 Posts
The engine tries to fire and starts stuttering
Is there any pattern to when that happens? If it stutters and you switch the engine off, will it start normally if you press the button again?
I assume the engine doesn't respond to the throttle when it's stuttering? So pressing on the gas wont increase RPM.

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #17 ·
Is there any pattern to when that happens? If it stutters and you switch the engine off, will it start normally if you press the button again?
I assume the engine doesn't respond to the throttle when it's stuttering? So pressing on the gas wont increase RPM.

If I helped you fix it, why not...

Your support is greatly appreciated
no pattern. sometimes starts fine for several times, sometimes stutters several times and wont start. engine does not respond to throttle when stuttering.
Handwriting Automotive tire Font Material property Writing
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
18,185 Posts
No "active" codes. So I wonder what the "inactive" codes were. I wish he had written them down for us.
And I guess he means it logged P0299 during the test drive, because P2099 is a fuel trim code and he said he inspected the trims.

engine does not respond to throttle when stuttering.
It sounds to me like the throttle is where the problem lies. My guess is the throttle is intermittently staying fully closed which is preventing air from entering the engine, causing the very low idle (stuttering). I wonder if the "inactive" codes the dealer tech found related to the throttle. I don't suppose you own a scan tool to check for codes yourself?

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #19 ·
No "active" codes. So I wonder what the "inactive" codes were. I wish he had written them down for us.
And I guess he means it logged P0299 during the test drive, because P2099 is a fuel trim code and he said he inspected the trims.


It sounds to me like the throttle is where the problem lies. My guess is the throttle is intermittently staying fully closed which is preventing air from entering the engine, causing the very low idle (stuttering). I wonder if the "inactive" codes the dealer tech found related to the throttle. I don't suppose you own a scan tool to check for codes yourself?

If I helped you fix it, why not...

Your support is greatly appreciated
Thanks for the feedback.
wouldn't a throttle trigger a code? also, why would the high side starter re-engage on low idle/no start ? why did the dealer label the P2099 as turbo underboost?
I am borrowing an autel scan tool to further isolate the issue. I had previously cleared all codes before going to dealer.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #20 ·
Thanks for the feedback.
wouldn't a throttle trigger a code? also, why would the high side starter re-engage on low idle/no start ? why did the dealer label the P2099 as turbo underboost?
I am borrowing an autel scan tool to further isolate the issue. I had previously cleared all codes before going to dealer.
Scanned all sensors with Autel. No codes. low pressure fuel pump tests fine.
I'm wondering if there is intermittent issue with ECU..
 
1 - 20 of 23 Posts
Top