The 5K stutter cutout misfire stumble breakup Thread [Merged 7-8]

[Newlogics]

My project 92 Talon just wouldn't be nice to me.

I figured that my smoking problem was due to my turbo leaking oil, since upper IC pipe had whole bunch of oil in it.

Now more porblems arize....

1st: It wouldn't idle normally, instead it revs up to 2K and drops back to 1K every like 2 sec. if idle is adjusted to be lower then 1100 rpm

2nd: When rmp reach 5K under WOT, it hesitates violently. As soon as rpms drop a bit, it's fine again.

(The good thing I fix the unlock buttons, 'cause it had shaved handles and you couldn't get inside by any means except a trunk....)

 

[cmjdskates]

To sum up:
1) Swapped in larger turbo
2) Raised fuel pressure to stock level
3) Replaced front O2 sensor
4) Started dicking around with dsmlink
5) RESULT while gently accelerating to 5Krpm I lean out and bog

I recently swapped out my 16G and installed a 60trim. Before the swap I wasn't having this problem.

In every gear as I'm gently accelerating in closed loop operation with my wideband reading 14.8:1 I find the car losing power at about 5Krpm. When this happens the wideband leans out until it's off scale and the car bogs down. If I go WOT at this point things return to normal with the wideband richening up to 11:1 and car feels strong.

After the swap I started retuning with my dsmlink and this problem arose, but I haven't correlated it with any specific change that I made. I adjusted fuel pressure a bit as it was too low on my previous tune (about 41psi on my 2G). I raised fuel pressure to 43.5psi and reset global and dead time.

I then started having problems related to fuel that turned out to be a bad front O2 sensor. I replaced that and now only have the 5K issue.

Thanks for the help

 

[cmjdskates]

The problem was with dsmlink. I got this reply on the dsmlink forum:

"Probably needs tuning to bring the LTFTs in line. Even though the ECU may stay in closed-loop above 4500 rpm, the 2G ECU stops using the LTFTs at that rpm. Where it might have been using a high positive LTFT Mid of +12.5% at 4490 rpm, the ECU will suddenly stop using the +12.5%, leaning out the mixture by 11%. It might also temporarily reset the STFT to zero at at that point.
Dave"

I reset the dead time and global and the loss of power at 4k rpm disappeared and the run is running MUCH better.

 

[JayRolla]

I was about to say your lo throttle is real lean.

 

[DsM KiD4]

heres the story.. My car was not boosting past about 5k. i looked for boost leaks and i found a huge crack on the underside of my stock 1g manifold. after i found that crack i bought an evo 3 16g and a evo 3 manifold. i put it all together and im still getting the same problem. the car bogs out around 45k - 5k rpms and only boosts up to 11psi. i also replaced my plugs (BRP8ES) NGK, and stock wires. other than a boost leak what could it be? i tried spraying soapy water onto my stock mesh licp but it soaks into the fabric to quickly and i cant see if bubbles appear. other than a boost leak, what do u guys think it could be? fuel cut? my only fuel mod is a 255lph walboro i put in a long time ago and didnt have a problem with it before when the car did run properly. any ideas?

 

[boostnhard]

do you have a AFPR if not that might be your problem!
when people run 255's they must install an AFPR

 

[DsM KiD4]

no i dont have one yet. but a while back when i first installed i had no problems. thats y i dont think its the 255. however, ive read its not good to have a 255 w/o an afpr but wouldnt the problem have happend rite after i installed the 255?

 

[TiradoCC]

yea you need to get a AFPR with that 255 fuel pump

 

[DsM KiD4]

ok but like i said. i didnt have these symptoms right after i installed the 255. would my ecu need time to recognize that its getting to much fuel? how long would it take to realize?

 

[turbosax2]

From what I've seen, only guys making big hp are using BRP8ES. Switch them back to 6's or maybe 7's and see if that helps at all.

 

[DsM KiD4]

ill switch em out with some 6es tomorrow and see if that works

 

[phreak965]

hi guys, i just bought a COMPLETLY stock 98 gs-t and it seems to lose alot of power (push ya back in the seat) @ 5k, is this normal for a stock eclipse? i tested for boost leaks and there was none, also changed the oil, and spark plugs since i just seafoamed the engine. thanks!

 

[BoostFrenzy]

hi guys, i just bought a COMPLETLY stock 98 gs-t and it seems to lose alot of power (push ya back in the seat) @ 5k, is this normal for a stock eclipse? i tested for boost leaks and there was none, also changed the oil, and spark plugs since i just seafoamed the engine. thanks!

Its the stock turbo. the T25 was being pushed pretty hard from the factory so there isn't really anything much left in it.

 

[Defiant]

Not so much that the T25 is being "pushed hard", but more that it's a street turbo. For street driving, it's pretty-well matched. It runs out of wind around 5K, depending on the immediate circumstances. But on the street, you should be shifting around there, which will put your revs back down where the T25 is at its best.
In fourth at fifty, the T25 does very well. Which is where a lot of real-world power can be used best.
If you want racing, you'll want something else. And as in racing, you'll be paying for it.

 

[crimsonGST]

my car is sputterin at 4k but REALLY bad at 5k. i think it might be a clogged injector? ive used that whole "injector cleaner" bs from local part stores...is this my problem? if so ill get 550cc's over here asap. please help.

 

[Shadow98]

Lol, what exactly do you plan on controling those 550's with..? Dude, you've got A LOT to learn. First of all, if you're car is running bad, you need to fix it before even thinking about going turbo. You're problems WILL only worsen once you go turbo. I remember you saying $2000 was to much for a turbo kit... So, stick with your stock injector, since all you'll need is a 255lph fuel pump and 12:1 FMU for your fuel system on 8-9psi of boost.

Now, the sputtering check you're wires, plugs, and coil pack. It might be eletrical.

 

[crimsonGST]

haha i know, i DO have alot to learn and thats exactly why im wasting away a perfectly good wednesday night talking to you guys (= i hope to learn more than just what ive learned screwing around with my car. and ive changed my wires and plugs so i know its not that. the turbo isnt going to come for a while (im only 17, part-time job in between football practice) so im not really worried about that rite now.

if its not my coil pack, what else could it be?

 

[Shadow98]

I'll warn you before a Mod does. Use capitalization and spell words fully/correct. Try swapping your coil pack with a friends (if your lucky enough). Other than that, you can test the coil pack. I'll post up what the resistance is supposed to be at later.

 

[crimsonGST]

Oh, okay, I'm sorry and thanks. How do I test my coil pack? I only have one friend with a DSM and his is a 1g turbo. Thanks for the help.

 

[Locke]

Primary coil resistance should be 0.51-0.61 ohms.
Secondary coil resistance should be 11.5-13.5 ohms.

Make sure your plug gaps aren't beyond 55 mils.

 

[crimsonGST]

Okay, and all I'll need to check them is an OHM meter?
I know how to check my spark plug gap
I'm serious when I said that I am just learning more than the basics.

 

[Locke]

Where the harness plugs into the coil-pack is the primary side of the coil. There will be three pins, the one in the centre is the B+, and those on either side are signal wires from the ECU. You will to use your Ohmmeter (or VOM/DVOM/whatever) to check the resistance between the B+ and either of the signal wires.

The spark plug wires plug into the coil's secondary circuit. The two terminals at the rear (left and right) are on one coil, and the two near the front are for another. You will check the resistance between the towers of each coil. For example, the terminals numbered 1 and 4 are on one coil, and the resistance should be checked between them. Then again for the #2 and #3 terminals.

 

[crimsonGST]

One word. Wow. I was definitely headed in the wrong direction and I really do appreciate the help. I've been wanting to get this fixed for a while, but with my limited knowledge, I didn't even know where to begin.

 

[Locke]

One word. Wow. I was definitely headed in the wrong direction and I really do appreciate the help. I've been wanting to get this fixed for a while, but with my limited knowledge, I didn't even know where to begin.

If you use first the search feature of this site (as you always should) and don't find what you are looking for, or don't understand it, ask away.

If you don't have a Chiltons or Haynes manual, it would be in your best interest to pick one up. Back in the day, I would keep 3 or 4 of them in the magazine rack next to the toilet as bathroom readers.

Casually reading the posts around here will benefit you as well.

 

[crimsonGST]

Okay I'll try that first next time.
and yes, I do have a chiltons book. I run to it all the time. Its just not very clear sometimes on trouble shooting things like this.

As for the forums, I LOVE reading them. Just everything about the dsm attracts me, so I'm learning as much as I can.

 

[Defiant]

For a 5K miss, start with wires. Then, plugs.