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Discussion Starter #1
Ek K swap race car.
So after hours and hours of testing and checking stuff I hope someone here can help.
Last season on high load right turns the car would die for a second and then catch again, of course thinking that we didn’t have enough fuel and it was going dry was the first assumption! Filled it to the absolute brim and got one lap in and it did the same thing and then ultimately died for good ish. Now the car starts for 5-10 seconds and turns off. But wait ! There’s more, while it’s idling for those seconds it doesn’t fire injector #3. And then when it’s sputtering out it fires 3 along with the others.
So far have, changed computer,map,crank, have 12v at the Injector and the trigger side has no breaks in it, constant fuel pressure, swapped injectors,coils, plugs. Nothing looks fishy on the data log side either.
Does anyone have any ideas at all??
 

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Sorry no great answer here but on track in long hard right turns turn I have seen vtec cut out, possibly due to oil starvation. This happened with a full tank. Maybe more than one issue.
 

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Discussion Starter #5
So after a lot of thought I decided to rip every wire out of the car and start from scratch. I tore the harness down to absolute basics. There is not one wire in the harness that isn’t used.
Engine harness will be completely separate from chassis harness, on its own relay with its own grounds.
Chassis harness will consist of fuel pump,headlight/tail lights, brake lights and wipers.
No more insane fuse boxes and immense amount of unused wiring. I’m around 10lbs saved so far.
 

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Arouse the DAMPFHAMMER!
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Does anyone have any ideas at all??
Did you measure the signals of the ignition coil (primary side) and fuel injector? An oscilloscope would be fine for this to see what is happening there.

If only one cylinder isn't firing it isn't very likely of an general sync problem, but it is always good to know #1 is just right on time for the ECU and the crank/cam sensors. Other points are:
  • TPS
  • MAP sensor
  • IAT sensor
if fuel injectors and coils itself are already verified to be functional. Anyway, your analysis will make you to the captain of your boat, knowing his stuff finally :).
 

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Discussion Starter #8
Does anyone have any ideas at all??
Did you measure the signals of the ignition coil (primary side) and fuel injector? An oscilloscope would be fine for this to see what is happening there.

If only one cylinder isn't firing it isn't very likely of an general sync problem, but it is always good to know #1 is just right on time for the ECU and the crank/cam sensors. Other points are:
  • TPS
  • MAP sensor
  • IAT sensor
if fuel injectors and coils itself are already verified to be functional. Anyway, your analysis will make you to the captain of your boat, knowing his stuff finally
.

Haven’t checked the reluctor wheel yet or the ignition signals,
injector,coil, plug ,iat,tps,and map have been checked. Both wiring side and verified on hondata data logging.

What’s weird is that every time after 10 seconds ish when it starts to die it started to fires that cly also. It only doesn’t fire when it’s running lol. I’m starting to be leaning more towards a burnt mother board. It’s the only way to have such weird problems. It’s not a very complicated motor to keep running.
 

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Arouse the DAMPFHAMMER!
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Haven’t checked the reluctor wheel yet or the ignition signals...
Would be an option for failures...

injector,coil, plug ,iat,tps,and map have been checked. Both wiring side and verified on hondata data logging.
What about the fuel pump? Is fuel pressure consistent and constant? I just think on that when I read it dies after a few seconds. What does change after 10 seconds? Normally the ECU switches from start operation into idle mode and reduces according time and ECT or further parameters the fuel to map level. If fuel pressure is to low, exactly that enleanment to reference map can be an issue. Just a 2nd thought to yours of an dead motherboard.
 

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Discussion Starter #10
Haven’t checked the reluctor wheel yet or the ignition signals...
Would be an option for failures...

injector,coil, plug ,iat,tps,and map have been checked. Both wiring side and verified on hondata data logging.
What about the fuel pump? Is fuel pressure consistent and constant? I just think on that when I read it dies after a few seconds. What does change after 10 seconds? Normally the ECU switches from start operation into idle mode and reduces according time and ECT or further parameters the fuel to map level. If fuel pressure is to low, exactly that enleanment to reference map can be an issue. Just a 2nd thought to yours of an dead motherboard.
I’m pretty sure i checked that last season at the track. But I will absolutely re confirm that today. As for the maps I don’t have a cold start so i believe it should be on the correct one from the start. I like your thinking though. And thank you !
 

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Arouse the DAMPFHAMMER!
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I’m pretty sure i checked that last season at the track. But I will absolutely re confirm that today.
You have also a very good list, seems we can check all the points on mine :D!

As for the maps I don’t have a cold start so i believe it should be on the correct one from the start...
Don't you have a K-series engine? The cold start mode is an inherently part of the ECU SW, which consists of following modes:
  • start
  • idle
  • operation according map incl. open and closed loop cycle
  • safety modes like ign. retard to reduce knock a.s.o.
  • correction modes like lambda IAT compensation a.s.o.
  • and a few others
These are those you will find also on your ECU. Cold start mode means an time based enrichment to overcome the wall film build up and the highly transient temperature gradient, which makes fuel wall film build up also a transient. No matter if you have PNA, PRB, PRA, PNC or whatever K-series ECU, all have to challenge this in some way. Enrichment is the only way for multipoint fuel injection type, means external mixture build up before combustion chamber. A direct injection type Otto engine may have less demand on enrichment when the engine is cold.

The ECT sensor is one of the indicators for the ECU to calculate the amount of enrichment, if it has an offset or is dead the start fueling is likely wrong. Something can be annoying if you don't know it :D.
 

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Discussion Starter #12
I’m pretty sure i checked that last season at the track. But I will absolutely re confirm that today.
You have also a very good list, seems we can check all the points on mine
!

As for the maps I
don’t have a cold start so i believe it should be on the correct one from the start...
Don't you have a K-series engine? The cold start mode is an inherently part of the ECU SW, which consists of following modes:
  • start
  • idle
  • operation according map incl. open and closed loop cycle
  • safety modes like ign. retard to reduce knock a.s.o.
  • correction modes like lambda IAT compensation a.s.o.
  • and a few others
These are those you will find also on your ECU. Cold start mode means an time based enrichment to overcome the wall film build up and the highly transient temperature gradient, which makes fuel wall film build up also a transient. No matter if you have PNA, PRB, PRA, PNC or whatever K-series ECU, all have to challenge this in some way. Enrichment is the only way for multipoint fuel injection type, means external mixture build up before combustion chamber. A direct injection type Otto engine may have less demand on enrichment when the engine is cold.

The ECT sensor is one of the indicators for the ECU to calculate the amount of enrichment, if it has an offset or is dead the start fueling is likely wrong. Something can be annoying if you don't know it
.
I kinda under stand what you mean. Correct me if I’m wrong. But the way my tuner set up the car is full race car tune. There’s no cold start map of circuit. I have no 02 sensors. It runs in open loop always. I believe the only thing that can affect my tune is iat and ect.
 

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Arouse the DAMPFHAMMER!
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I kinda under stand what you mean. Correct me if I’m wrong. But the way my tuner set up the car is full race car tune. There’s no cold start map of circuit. I have no 02 sensors. It runs in open loop always. I believe the only thing that can affect my tune is iat and ect.
Mmmhhh...which ECU brand and model is it?
 

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Discussion Starter #14
I kinda under stand what you mean. Correct me if I’m wrong. But the way my tuner set up the car is full race car tune. There’s no cold start map of circuit. I have no 02 sensors. It runs in open loop always. I believe the only thing that can affect my tune is iat and ect.
Mmmhhh...which ECU brand and model is it?
Kpro prc
 

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Discussion Starter #18
Humm. Ok well he definitely doesn’t tune for it very well. Car runs terribly at idle. Always.
Does the engine setup have a non-VTEC cam? Could you please list the engine setup here?
Engine set up is super standard.
ips vtec Cams and with oem cam gear and drag cartel exhaust gear.
Aside from that bottom end is stock with the good oil pump.
 

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Arouse the DAMPFHAMMER!
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...ips vtec Cams and with oem cam gear and drag cartel exhaust gear...
Wow, those cams still exists?! There was once a Centerline issue with the SVMCAMS (IPS cams are made also by Nikos, the owner of SVMCAMS), which would come up if the engine was clayed. Was it clayed by the tuner?

Anyway, could you please send me the calibration and a start and idle log file to see what is done and happening there? I will PM you my email address.
 
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