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Old 04-13-2009, 09:18 PM   #1
Max777
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Default Idle issues, Car runs better with BAC unplugged, stalls when coming up to a stop sign

Ok, this is a continuation of a previous problem.

The car starts just fine, then idles kinda high, and then the idle goes down and it stays idling. Sometimes the car will die if it isnt fully warmed up. When I try to press the gas at all, the engine just falls flat on it's face and dies.

I have now gotten an RTEK 2.0 for my car and took some logs, however the ECU will not let me disable the MOP for some reason (says "unsuported") for whatever reason.

Interestingly enough, I hooked up the stock ecu and the car started and ran, but would not rev, now that I finally hooked up the RTEK the problem remains. I got some data logs but i dont know how to upload them to the PC?

One thing I noticed is that the AFM air temps and IAT sensor aitr temps varied by 20*F. I dont know if this afects anything on this car.

Some things I did:

made sure there are no vaccum leaks when I reassembled the manifold the second time.

removed emissions, all new vaccum hose, put RTV and bought new gaskets for everything, ziptied vaccum caps, and just generally made sure everything is nice and good.

Tested TPS: on the bench it checked out ok, then I adjusted it with a self made TPS tester yesterday, it was way out...

Tested AFM, here are the results:

E2-Vs terminals: closed: .400K ohms open: 114 ohms

spec is:closed: 200-1000 open: 20-800

E2-Vc closed-open: 279 ohms value does not change between closed/open.

E2-THA: @ ~45*F I got 3,693 ohms, this in alldata specs is around ~32*F, so this value seems in spec.

I tested the TPS that originally came with the car and it checked out ok. I DID buy a new throttle body and another sensor that came with that was bad... so i put the OEM one on.

I will have more info in a bit.






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Old 04-13-2009, 09:47 PM   #2
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with as little time as you have I would be trying as many spare parts as I could... mainly afm, and tps.

obviously its not compensating for you pressing the pedal by adding fuel, so it doesn't know your pressing the pedal or doesn't know its getting air... If I remember correctly the car won't run at all with a bad MAF. Have you tested the tps sweep for dead spots? Tested resistance at the beginning and end of the sweep?

Are you 100% sure you don't have a ginormous vacuum leak?
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Old 04-13-2009, 10:11 PM   #3
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Did you hook up the primaries to the secondaries on the harness and vice versa not that I have ever done that before...
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Old 04-13-2009, 10:27 PM   #4
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Quote:
Originally Posted by vex View Post
Did you hook up the primaries to the secondaries on the harness and vice versa not that I have ever done that before...
is that physically possible?
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Old 04-13-2009, 11:42 PM   #5
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is that physically possible?
Yes
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Old 04-14-2009, 01:37 AM   #6
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I am pretty damn sure I did not hook them up backwards.

I have an S4 map sensor I borrowed, as well as my original CAS, the one in there right now came with the shortblock 13B I bought, and I was wondering if maybe that could be it?

Would a bad CAS cause this type of problem?

I will call Kevin, Chris Ludwig, Banzai, digital tuning, and a couple other places to check.

If I bought anew TPS, and it didn't solve the problem, can I return it? lol

Man, I really wish I knew how to diagnose stuff better, Tech schools can only each you so much in a semester...
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Old 04-14-2009, 03:13 PM   #7
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Ok, so I spoke to Chris Ludwig, who sold me the RTEK, and it turns out that the unit he sold me was actually an older unit that did not have the MOP feature available. I explained to him how I blocked off my MOP, and trimmed the plug off the harness, and he told me that this might be my problem.

I called DTI, and sure enough, the unit is one of the earlier models which does not feature the MOP delete option. Fortunately, I can order an update chip for $10 and then it should be up to date on all the specs, including the MOP option.

This has given me much relief, and is very likely all that there is to my problem, however this also means that I will not be able to drive to DGRR this year.....

Oh well, there's always next year, and apart from this little issue, which was out of my control, I kept my promise to get it done and running by DGGR!

If there are still issues after I install the chip, I will update this thread again.


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Old 04-14-2009, 04:58 PM   #8
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Here's a video of the car running, sorry for the bad quality, i took it with my cellphone.

http://www.youtube.com/watch?v=4rV8dKq7ALw
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Old 04-14-2009, 05:19 PM   #9
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strip the harness back and splice in the wires!!! I'll send you a pigtail if you need it...
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Old 04-14-2009, 05:51 PM   #10
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Worst video evar.

Seriously, that's not limp mode. Vac leak is what I would guess.
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Old 04-14-2009, 09:43 PM   #11
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i know it sucks.... oh well, I ordered the chip... (it was only $10 to update)I'm going to get a can of propane or something to test for leaks.... and get a better video camera.
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Old 04-15-2009, 05:12 PM   #12
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Yeah dude, splice the OMP back in, tie it back and roll on!!!
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Old 04-15-2009, 05:36 PM   #13
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Ok, so if it's not a ginormous leak (at the intake tube) then look at your spark to make sure the leading coil is firing right....I was just twlling someone else about the spark and thought about your problem max....

This is a tough one.
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Old 04-15-2009, 07:54 PM   #14
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Ok, so if it's not a ginormous leak (at the intake tube) then look at your spark to make sure the leading coil is firing right....I was just twlling someone else about the spark and thought about your problem max....

This is a tough one.
I think that isn't the problem. He said the Rtek will not let him disable the OMP, so that part of the ECU requires it to be there.

Without an OMP plugged in- no go!
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Old 04-15-2009, 08:04 PM   #15
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but it'd go into limp mode without the OMP, no?
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