Boost issues after 1st gear

[xyexz]

So just finished up a project build (91 TSi AWD 5Spd) and after replacing some electronics I've gotten down to what I think is the last issue with my build.

Engine has maybe 40 miles on it, all forged internals, balance shafts removed, head is ported polished with 1mm oversides valves, stock cams for now stock springs as well (wanted to break it in with mostly stock head and not spend so much money on head until I knew the car would be worth it haha).

I saw this thread here:
http://www.dsmtuners.com/forums/new...ut-no-other-gears-hold-boost-help-please.html

But it didn't get any responses that were really helpful.

So I'll ask here and hope I get some better responses.

Main Issue:
I have a full exhaust and dump tube, 14b turbo nothing fancy and when driving under normal driving conditions I get nice smooth boost in 1st gear but any other gears barely get any and smashing the gas down to the floor results in me maybe getting to 50mph in any 3-4th.
I once let 1st gear get up to 4500 rpms and when I shifted to 2nd some black smoke came out the back but I think this may have been some excess fuel buildup since the car sat for a couple of months and when I tried to start it today the ECU had gone bad, but after replacing ECU today she started right up but just the power issue is plauging me.

So I need some ideas on where to look because I honestly haven't the slightest clue where to look after what I've already looked into.

I did a full boost leak test with tester @ 10psi, used soapy water on everything I could find and found no bubbles/leaks and I've tried 3 different throttle bodies all for my make/model to no success (tried these because I've read that the seals can go bad in them and cause nice giant boost leaks).

I've removed all of the crap for being environmentally friendly following guides on here and what my friends did with their running talons.

Gas is new and fuel filter isn't that old, injectors were pulled from running car and still nothing.

Spark plugs looks decent and wires are newerish, battery is charging 14.5v @ idle.

The other thing about my car is it idles way to freak'n high, around 2500-3k. I've used the BIS screw and it didn't make hardly any difference and the car is in time.

So please I hope someone has some suggestions for me, I'll try whatever doesn't matter to me as I'm not in much of a rush.

Thanks,
Brian

Edit: Did a compression test and that isn't the issue either, all were over 160

 

[dented_coffee]

ISC also known as the IAC. That could be bad. Did you test it with an ohms's meter? Did you take the proper steps in adjusting the BISS on the TB? When you don't adjust the BISS properly it can lead to the ISC getting burned out really fast in a big old hurry! Also your MAF might be bad as well. Try unplugging your MAF and see if the problem persists. If it does then it's probably bad . If you need a MAF I have one for really cheap that is in great condition and I have a current vid to show of it just PM me. I put a 2G MAF in my 1994 Talon because it was given to me and I didn't have the air tube for the 1G anymore .

The ICS has a single harness plug with 6 wires that plugs into it. It is mounted directly on the TB toward the bottom on the passenger side of the car. They usually have a tan or black plastic cover on a small aluminum body and 2 small bolts that hold it to the TB.

When you unplug the ICS test it like this and make sure that all the OHMS readings are within 28-33ohms. I would take it out of the car and clean the end of it off because it will have a bunch of black residue on it. The tip of it is plastic so don't go grinding on it . A small bristle brush and some mineral spirits will do fine. Test it while its out and install it when it's all dry.

If any of the readings are out of the 28-33 ohms then your ICS is going bad and if you get no reading at all that means that its completely burned out. I have rebuilt the ICS before because mine was bad. I wasn't gonna buy a new one with a price tag as high as it is. I bought a used one and it was bad as well. Lucky it was only one pack that was bad just like my original one was.

CONNECTOR DIAGRAM

TOP
1 2 3
4 5 6

TEST SEQUENCE's
1-2
2-3
4-5
5-6

HERES HOW I FIXED MY ICS
1. I took all 3 philips head screws off the plastic cover.
2. Pulled it off the aluminum housing carefully.
3. Flipped the plastic cover over to get to the 6 tabs that are soldered to the packs inside the ISC motor.
4. De-soldered all the tabs on both the ICS's.
5. Tested all the packs from both ICS's and picked the 2 that were all in spec.
6. Placed the packs in the correct order and re-soldered the connections with new solder.
7. Cleaned up the rubber gasket and inspected it for any damage then placed it back on the plastic cover.
8. Then re-assembled the ICS and put blue locktite on the 3 screws.
9. I tested everything again to make sure that everything was perfect still.
10. Finally I put it back in my 94 talon and set the BISS screw and shes been running perfect ever since.

 

[xyexz]

Ok thanks for that I will test it... I'm assuming you're thinking iac/ics for the idle issue and not the boost issue?

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