Injector/Duty cutting out while driving

2000Accord5sp · Post by **2000Accord5sp** » Mon May 15, 2006 1:31 pm

Sorry if this is considered clogging the forum but I felt my other title was too ambiguous and now I have more detailed info that narrow this issue to this:

Car: 1993 Honda Civic DX
Engine: 2004 Acura TSX 2.4L
Transmission: 2004 Civic EP3 Civic Si
Engine Harness: 2004 Civic EP3 Civic Si
ECU: 2004 Acura RSX Type-S
Calibration: k24-tsx-stock.kal

This issue is very apparent in two situations:

Cold start:
I loaded the cold start data log where the car idles very rough (between 1300-1800rpm maybe?). If you look at the datalog, the injectors/duty are turning off and on very frequently...as the car warms up, this slows down until eventually it idles correctly and the injectors stay on.

WOT pulls:
I loaded a 2nd to 3rd WOT pull. During the 2nd gear pull, you'll see that the injectors just momentarily shut off briefly and come back. This results in a huge 'bogg' while accelerating.

Any suggestions as to what could cause this?

Post by **Spunkster** » Mon May 15, 2006 2:51 pm

Either the engine has a problem or you have a bad vacuum leak as you are only pulling about 14 inches of vacuum when idling...this gets slightly better as it warms up, but is still low.

2000Accord5sp · Post by **2000Accord5sp** » Mon May 15, 2006 3:03 pm

That's a great point. I didn't think about that. I DO have a few plugs that could have easily come off the intake manifold so I will check those. Thanks.

2000Accord5sp · Post by **2000Accord5sp** » Mon May 15, 2006 3:23 pm

If it is an engine problem, what is typically this a sign of? blown head gasket? ...etc? I really have no idea what could cause this if it's a bad engine.

To give a brief history of when it started to happen, I was taking off in 1st gear and hit redline, then the check engine light came on. It felt like the engine went into limp mode. I turned it off since I didn't have my laptop with me to see the error code. Once I turned it on, the engine light went away however ever since then, the bogging has started.

Post by **Spunkster** » Tue May 16, 2006 11:54 am

You may have bent a valve, or have a bad ring or problem with a piston.

2000Accord5sp · Post by **2000Accord5sp** » Fri May 19, 2006 7:15 am

Ok, followed instructions for FSM on checking the crank sensor...all steps pass...last step says to replace/upgrade ECU. Could my ECU be broken/messed up?

I'm going to take my car to the shop for any mechanical damage...if there is none, any other suggestions as to what might be causing this?

I also loaded the stock RSX calibration and then reloaded my TSX calibration to see if that helps...but no go.

2000Accord5sp · Post by **2000Accord5sp** » Fri May 19, 2006 7:02 pm

Okay...any suggestions would help. In my original post, I attached the cold idle datalog where the injectors and duty keep jumping between normal and 0.

Sooo, since I was trying to troubleshoot it, a fellow k swap guy came over and let me try his ECU. Started the car from cold start and no problem....idles perfect....plugged my ecu back in and it idles crazy with the same problem again.

WHAT could this be? Bad calibration or ECU?

Post by **Hondata** » Sat May 20, 2006 11:09 am

Well, try loading your friends calibration into your ECU. If it works, it is the calibration. If it doesn't work, then it is the ECU.

2000Accord5sp · Post by **2000Accord5sp** » Sun May 21, 2006 12:09 am

Okay, loaded my friends calibration (TSX tuned) and it still behaves the same. Do I need to send in my ECU if I feel it's bad or can I take it to a hondata certified shop to have them check it out for me?

I have a hondata certified shop really close so if I can do that, it would be a lot easier for me...but if i have to send it in to get checked, that is fine as well. Should I call to talk to you guys?

Post by **Hondata** » Mon May 22, 2006 9:16 am

The injectors are shutting off at idle because the idle speed is too high. At cold start the MAP reading indicates something is wrong - either tunign or mechanically. The AF is too lean which could be causing a lean cut at WOT. Get the car dyno tuned.

2000Accord5sp · Post by **2000Accord5sp** » Tue May 23, 2006 10:14 am

Thanks for the suggestions...will do that.

Out of curiosity (can't find any numbers in the manual or online), what numbers should I see for the MAP when not under load?

For me, I'm seeing 50-70 kPa on cold startup and as it warms up, going down to 37 kPa.

Post by **Hondata** » Wed May 24, 2006 8:50 am

Your MAP readings are a little high, but that could be tuning. 40 kpa after a cold start going down 30 kpa is normal.

2000Accord5sp · Post by **2000Accord5sp** » Wed May 24, 2006 2:27 pm

Okay, I know this is stupid...we're told over and over to check grounds. I have three grounds.

However, by suggestion from a mechanic, I used jumper cables from the negative battery terminal to the tranny and started the car up. idles perfect. MAP red around 42 and then once warmed up, went down to 37.

So I took sandpaper on all 3 grounds that were on the body and sanded everything to bare metal. Not sure if my ground wires are bad (two of them are original ground wires from the 93 civic) but it seems to idle perfect, I'm able to rev just fine without bogging.

Will try to drive tonight but I think everything is fixed now. I HOPE I HOPE I HOPE.

Thank you for your patience with me andsering my posts...

cxcivic · Post by **cxcivic** » Thu May 25, 2006 2:14 am

also at idle your tps is at 1%. might want to set it at 0%

2000Accord5sp · Post by **2000Accord5sp** » Fri May 26, 2006 9:29 am

Yea, I've been meaning to fix that. Just scared to tap too hard and break the TPS. :P

So I drove it finally and yes, everything is fixed. Drives perfect again and no bogging or odd issues anymore. Just my exhaust rattle on the heatshield. :P

Thanks again for your guys help. Hopefully getting it tuned Tuesday!