Stutter at low rpms?

[AWDTSIer]

Ok i just swapped a 6 bolt motor into my 1Gb, fresh rebuild and still on break in time. But at low rpms it acts as if it studders until it hits 3000 rpms then runs fine. I am running it with the boost set to 10 lbs for the break in time. Anyone have any clue what could cause this? Also iam am running a 2G mas with a 3" intake pipe, but when i disconnect the mas plug nothing changes, it has me stumped!

Here is a list of my mods:
MHI 16G turbo
2G mas with 3" dejon intake pipe
3" turbo back thermal exhaust
.20 over pistons, stock comp
Magnacore wires with iridium plugs

 

[boostngsx]

What do you have for fuel mods?

 

[2GAWD4U2NV]

You may be running bad rich and the higher rpms are able to use up most of that fuel allowing it to run properly.... Or you have air that has not been compensated for and your A/F ratio is off. I had a loose UICP and was still able to run WOT just fine. Taking off was the problem. I would check the couplers on the intake-turbo side, air filter to maf, then maf to intake. If that all checks out, check your LICP and then your UICP right around the BOV. After that it's up to the TB elbow. You should invest in some type of logging system. Ex. (DSMLink, AEM EMS, GReddy E-manage) Personally I'd go with DSMLink. I hope this helps.

 

[AWDTSIer]

I have no fuel mods, also i just ordered a fmic kit that will be here on friday so all my IC pipes should be fine once i replace everything. I just got done removing the TB elbow any the body itself, it needed a cleaning bad! . But still no change. Another thing, when i bought the shell they had a DSM chip installed in the ecm and the harness before the ecm is a little hacked up. Idk what to think of that? Anyways i put a stock ecm in from a 92 1Ga thinking it would help but didnt.

 

[2GAWD4U2NV]

By the way it sounds, if a replacement ecu of the same make/model didn't fix it, depending on how bad they "went to town" on the wires that could possibly be your problem, that is once you check all your ICP. If it still does it with a 100% satisfaction on your ICP, you may need a new engine wiring harness. I've never had to rewire mine, but it probably wouldn't be a very fun replacemnt.

*Make note to really really inspect A/F wire going into the ecu. Here is a reputable site with the ecu pinout. Find the corresponding wire and MAKE sure it is not hacked up. If it is, that will make your car act up, as on my first A/F guage I messed mine up and just so happen had a spare harness and swapped the wires out. They may have had one and when they took it out they didn't do a good job repairing it.

*Site: 1G ECU Pinouts

GOOD LUCK! Let us know how it's going!

 

[AWDTSIer]

Ok thanx for the info, im kinda new to the DSM life, . I will check this out and let ya know how it works out for me tommorow!

 

[AWDTSIer]

Okm i just got dne going over my wiring going into the ecu and it really wasnt as bad as i thought. Here is a list of what i found hacked:

pin 3 - Turbo gauge
pin 101- Ground
pin 109- Ignition pulse detect

 

[2GAWD4U2NV]

Hmm.. I don't think any of those would effect it. Sounds like it may have been loose ICP. To fix the wires though, you could wire cap them. That way you know they are getting a good connection. That's what I do when I splice into any electrical wires on my car. Inexpensive and they work amazing. Keep us updated.

 

[98gst14b]

Dont get mad for me asking but have you tried a boost leak test? I had similar symptoms from leaks in the ic piping.

 

[AWDTSIer]

This car has me clueless...i just went over all of the piping and clamps. All were good and tight! But still when i unplug my MAS it doesnt effect the car at all? That is not normal, heck i can even take the MAS off and it will run with just the intake pipe.

 

[AWDTSIer]

No i havent done a boost leak test, I have went over every inch of all the piping and havent found anything that would make it leak?

 

[2GAWD4U2NV]

If you unplug the MAS and there aren't any problems, it sounds like they had an Air/Fuel Controller. Ex. S-AFC, or possibly a MAF Translator. Possibly an Eprom ECU with configured settings for a blowthrough set-up. I'm not for sure how to fix that problem other than get your own and tune it right.