M20 will not rev past 3,000rpm

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ivprodigy
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M20 will not rev past 3,000rpm

Postby ivprodigy » Sat Mar 29, 2014 3:08 am

I realize I'm a noob but this is something I can't even wrap my head around.

I'm running the diypnp ms2 on the stock 2.5i with a mild cam and valve springs.
The car idles well at 1100rpm and ~13afr.
Engine revs up ok until it hits 3000rpm where it just cuts off and will not rev any further.
The fuel, ignition, and afr maps I think are pretty straight forward.

I took a quick video of what I'm talking about.

I can really use your input to get past this 3k ceiling


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Last edited by ivprodigy on Sat Mar 29, 2014 1:45 pm, edited 1 time in total.
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Re: M20 will not rev past 3,000rpm

Postby M20_fever » Sat Mar 29, 2014 5:20 am

Fixed you video, you just put the string after the last '=' in the embed.

Is this one of Whodwho's PnP's? I had a very similar problem with my MS3x and it was a wrong jumper on JP1 and J1
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Re: M20 will not rev past 3,000rpm

Postby ivprodigy » Sat Mar 29, 2014 1:53 pm

Thanks!

So as the story goes I got the car from Alabama just about a year ago. It came with just about everything except the engine was in pieces.

I spent the better part of my free time putting it all together. I think I'm car savvy but putting something together not having done it before or taken it apart before to see how it was supposed to fit together was a challenge.

The ms is the kit from DIYPNP Bosch 55pin Unassembled Kit that the po put together. I think it's this http://www.diyautotune.com/catalog/diypnp-bosch-55pin-unassembled-kit-p-385.html.

This is what it looks like inside (I don't remember seeing any jumpers aside for the boot one):
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Re: M20 will not rev past 3,000rpm

Postby M20_fever » Sat Mar 29, 2014 3:09 pm

Your MS2 should be similar to my MS3x, but I'm not super familiar with it. Read this, Chris gave me some great things to check before I found my problem.

http://www.e30tech.com/forum/showthread.php?t=100756
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Re: M20 will not rev past 3,000rpm

Postby ivprodigy » Wed Apr 02, 2014 2:44 am

I too thought it may be on of the jumpers or the 18k ohm resistor on VR+.
I took the box apart. The VR+ wire actually broke as I was pulling the boards apart so I soldered it back in.
I'm still having a hard time syncing with my computer in addition to the inability to rev past 3k rpm and it seems that there still some wiring issues with the MS unit...
The quest continues...
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Re: M20 will not rev past 3,000rpm

Postby M20_fever » Wed Apr 02, 2014 1:31 pm

You should send Whodwho on e30tech (maybe r3v too?) An email. He's a serious expert on ms2.
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Re: M20 will not rev past 3,000rpm

Postby ivprodigy » Wed Apr 02, 2014 2:31 pm

My computer gets disconnected from MS constantly which may be due to the loss of the rpm signal which is causing MS to un-sync itself from tunerstudio (and it may be the reason why the car will not rev)

I'm talking to Matt at DIYAutoTune right now and he's trying to narrow down why the rpm signal is getting dropped.

I've read many of WhodWho's threads and he'll be my next stop for sure.
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Re: M20 will not rev past 3,000rpm

Postby M20_fever » Thu Apr 03, 2014 1:55 am

I had the same sync problem when I wasn't getting full rpm range. Do you have a stim to test the unit with?
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Re: M20 will not rev past 3,000rpm

Postby ivprodigy » Thu Apr 03, 2014 3:06 am

I don't have a stim. I may have to look into getting one...
I was able to run the car without getting a sync error (disconnecting completely) to get a tooth log and sent it to Matt.
I was going to try using the noise filtering feature but the car may be flooded (if that's possible) as it won't start. I think I loaded the wrong tune trying to sort out VE table.
I'm tired and its cold so it'll have to wait until monday (spending the rest of the week in the city).
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Re: M20 will not rev past 3,000rpm

Postby Yoshi » Thu Apr 03, 2014 11:11 am

I remember doing all this BS with my MS. Sometimes the starter overheats or the battery just gets tired. You do too. I'm glad you got the sync errors gone. that's the majority of the problems I had. Mine were mostly due to wrong settings thankfully.
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Re: M20 will not rev past 3,000rpm

Postby blasphemy101 » Thu Apr 03, 2014 2:59 pm

ivprodigy wrote:I was going to try using the noise filtering feature but the car may be flooded (if that's possible) as it won't start. I think I loaded the wrong tune trying to sort out VE table..


Doubt that's the case. I realize you're just trying to get everything working correctly to get the car started.

Once you do get it started, if you have trouble getting it to idle, take a look at your VE table. I imagine it's going to run seriously rich and might idle super low or refuse to idle at all.

I second the recommendation for asking whodwho for some help. He was a great help even though I did not buy my MS unit directly from him (he built it, but I bought it second-hand and broken). He's also on r3vlimited.
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Re: M20 will not rev past 3,000rpm

Postby ivprodigy » Thu Apr 03, 2014 4:31 pm

The car normally idles ok. Its idling kind of high at ~1100rpm but afr is in the 13-14 and kpa is in the 60-70 range so it's a decent start point (would like it to be lower but I'll take it for now).
The car wasn't running well last night because I was stupidly trying out different base tunes I found around the forums which made things worse. I gave up and will be picking things up monday.

Since the MS is from DIYAutoTune, I started talking to Matt (Cramer i think is his last name).
I've given him the tooth log file and still waiting on some of his feedback.
I don't want to bug whodwho yet unless things dont go well with Matt.
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Re: M20 will not rev past 3,000rpm

Postby M20_fever » Thu Apr 03, 2014 4:52 pm

Matt is a good guy, he shoukd be able to get you fixed up.
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Re: M20 will not rev past 3,000rpm

Postby ivprodigy » Thu Apr 03, 2014 5:08 pm

He just got back to me saying that I'm getting noise pulses through where there should be a missing tooth. I'll have to try a larger resistor or a 10K resistor in series with the existing resistor at vr+

Yes he's been very responsive
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Re: M20 will not rev past 3,000rpm

Postby M20_fever » Thu Apr 03, 2014 6:49 pm

Very common problem. I thought the thread I posted covered that?
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