Bogging down when trying to pull away quickly

kyle'87

Advanced Member
Messages
389
I have been having this problem for a while and it has got to the point I would like to try and get it fixed.

The problem manifest itself in the following way:

When attempting to move off quickly (in first gear) If I don't get the engine revs high enough (above 2500/3000) when I engage the clutch the engine bogs right down to below 1000rpms. If I keep my foot flat to the floor at this point the car will try to accelerate, it feels the same when you are going up a steep hill in 6th gear.

I'll try and get a video up to show what I mean.

No CEL codes at all.

so far I've thought/ read about the following:

  • Servicing the car (happening next month)
  • Changing the plugs (only been in 12 months)
  • Changing the ignition coils (expensive fix! not normally a problem part in Honda)
  • Changing the primary 02 sensor (current one only 18 months old, no CEL light yet)
  • Tightening the throttle cable (is already tight, may need replacing if stretched)
  • Investigate fuel delivery (change with OEM filter about 2 years ago)
  • Change ELD (Done this, no difference)
  • Change intake temp sensor
  • Potentially get my map looked at

This all started to become noticeable after I had a new clutch fitted. Would it be sensible to say that on the old clutch I would have had much bigger gap to get away with moving off quickly with lower revs where as now I need to be much more aware of the revs I engage the clutch with?

I plan to do some logging this weekend to try and see what the car is doing component wise when the car is bogging down.

Kpro dashboard log video
[youtube]https://www.youtube.com/watch?v=wJb4m26BDfY[/youtube]

you can see the first few launches may sound like I am dumping the clutch but I am not. The only way to get away quickly is to slip the clutch, which as Luke said, might be the way I need to learn to drive with a new clutch.

What I find odd is the MAP dropping to 0 when the clutch comes in, is that normal?

Something in my head says that the car is mapped based on the MAP readings. So, if the TPS was at 10% and the map when to 0 when the clutch comes in then the fuelling would be out hence the bogging.

Surely the MAP would only be at 0psi (even pressure between inlet pressure and atmosphere) when the throttle butterfly is fully open which is 100% TPS. This would correlate with having to have high revs to get away quickly because the MAP will not drop as the pressure difference will be as expected.

Secondly, why would the map drop so low when the clutch comes in?

Any ideas?
 

kyle'87

Advanced Member
Messages
389
Chris. said:
What clutch was put in and who did the work? Maybe the flywheel is past its best?
The clutch was a honda OEM one and it was replaced at TGM.

Didn't consider the flywheel, I will do some research, thanks.
 

MilanoChris

Advanced Member
Messages
5,649
I would have thought Tom or Lio would have mentioned if the flywheel was past its best. If it's happened since TGM did the work I would be giving them a call to see what they think the issue may be and if it could be related.
 

kyle'87

Advanced Member
Messages
389
Chris. said:
I would have thought Tom or Lio would have mentioned if the flywheel was past its best. If it's happened since TGM did the work I would be giving them a call to see what they think the issue may be and if it could be related.
I did think Tom would have mentioned it.

I will give them a call to see if I can get any advice.

Thanks Chris.
 

tricker_luke

Advanced Member
Messages
1,574
Maybe it is like you say, possibly the old clutch was slipping a bit so you had a bit of allowance but now it is biting more efficiently there is no slip.
 

Johngreen537

Advanced Member
Messages
1,474
If it's only started after the clutch replacement, give TGM a ring.

If you roll in 1st slowly, with clutch not depressed, then floor it, does it not down then? That would confirm the clutch is the issue, rather than engine or sensors.

Sent from my SM-G955F using Tapatalk
 

kyle'87

Advanced Member
Messages
389
Chris. said:
WTH that's seriously broken!


Sent from my iPad using Tapatalk
agreed lol

Johngreen537 said:
If it's only started after the clutch replacement, give TGM a ring.

If you roll in 1st slowly, with clutch not depressed, then floor it, does it not down then? That would confirm the clutch is the issue, rather than engine or sensors.

Sent from my SM-G955F using Tapatalk
If I roll in first and then floor it, it bogs down and eventually gets going. Other times it will just keep going and rpms never increase.
 

tricker_luke

Advanced Member
Messages
1,574
Could it be something silly like a vacuum hose been knocked off or something?
I can't think what else could have been disturbed during a routine clutch change!
 

Grano

Member
Messages
20
Hard to tell from the vid, but it looks to me like your TPS is sticking. I would do a datalog in Kpro, calibrate it first, the with ignition on but engine off go from off to full throttle and especially about 1/5th way down, check the TPS % is moving correctly with your foot position. Maybe it got a knock when the had the intake out to do shifter cables etc? It's acting like how mine did when the TPS was on the way out...
 

kyle'87

Advanced Member
Messages
389
tricker_luke said:
Could it be something silly like a vacuum hose been knocked off or something?
I can't think what else could have been disturbed during a routine clutch change!
I honestly don't know. I'm thinking I have some sort of vacuum leak but where from is anyone's guess. I think I might take off the RBC mani and check for cracks and while I'm at it replace the inlet gasket.

I will be calling TGM today to see if they can give me any advice, I also have the belief that a routine clutch change can't produce the symptoms I have. I think the clutch is maybe exaggerating a problem I wasn't seeing before the change.
 

kyle'87

Advanced Member
Messages
389
Grano said:
Hard to tell from the vid, but it looks to me like your TPS is sticking. I would do a datalog in Kpro, calibrate it first, the with ignition on but engine off go from off to full throttle and especially about 1/5th way down, check the % is moving correctly with your foot position. Maybe it got a knock when the had the intake out to do shifter cables etc?
The TPS was replaced about a year ago as it was knackered. I'm pretty sure the TPS is OK at the moment as it is something I regularly monitor (due to the nature of them). I do wonder if a stretch throttle cable can produce this issue. It doesn't seem stretch but then again I have no idea how to tell.
 

tricker_luke

Advanced Member
Messages
1,574
Maybe also check the 02 sensor is looking ok and has been reconnected. They would have removed the exhaust manifold to get the subframe off.
I suppose a number of things could have been disturbed but it's knowing what would cause those symptoms.


Ignore that, the manifold is above the subframe!
 

Grano

Member
Messages
20
Well you have eliminated most other things, but I doubt it would be the cable. But who knows? To me it seems like TPS or MAP sensor, or like has been said, a vacuum leak somewhere. Have you re-uploaded your .kal to eliminate a corrupt map?
 

kyle'87

Advanced Member
Messages
389
tricker_luke said:
Maybe also check the 02 sensor is looking ok and has been reconnected. They would have removed the exhaust manifold to get the subframe off.
I suppose a number of things could have been disturbed but it's knowing what would cause those symptoms.


Ignore that, the manifold is above the subframe!
I've had the 02 sensor off a few times while getting my solid fab manifold fitted. The 02 sensor throws a code once in a blue moon and it is only when reversing down my drive way. So I pout that CEL down to over/ under fueling while rolling back down the drive way.

Grano said:
Well you have eliminated most other things, but I doubt it would be the cable. But who knows? To me it seems like TPS or MAP sensor, or like has been said, a vacuum leak somewhere. Have you re-uploaded your .kal to eliminate a corrupt map?
I have a spare MAP sensor that I've tried and I get the same results :( I do however have a K-tuned V2 TPS to go on but my map is locked by the mapper and so I can't easily download, calibrate the Ktuned TPS (when i decided to fit it) and then re-upload.
 

kyle'87

Advanced Member
Messages
389
UPDATE:

I spoke with Tom at TGM and he was pretty confident that the clutch change wouldn't directly effect the manifold pressure when bring the clutch in, and to be honest, that makes total sense. Tom mentioned that it sounds like an issue in the map in one of the 0 degree tables. I'm thinking of taking it to a mapper and having it remapped again, I just didn't want to take an unhealthy car to get a remap.

I am going to strip off the inlet this weekend (weather dependant) and replace all gaskets to see if that helps.

Other than that, I think it is time for a refresh map.
 
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