5KTQ broken when Ice racing now fixed

[Nate Stuart]

Timmmy said:
> Hi ALL
>
> way back when it was still snowy I managed to do something to my 5KTQ
> while ice racing that caused it to not build any boost , and not rev past
> about 3.5K.
>
> After much investigation I could not find the issue, gave it to Chris at
> Force5auto, and he had it for ages and couldnt find the problem either.
> Between us we checked just about everything. Then Chris had a flash of
> inspiration and found the problem.
>
> Melted the new 3" highflow cat, so bad it blocked the exhaust to the point
> it could not exhaust enough gas to let the engine build boost.

Yup, that'll do it. :)

> Have since fixed it, put and AR gauge on it and it was definately running
> lean. Anyone out there have any recommendations for additional injectors I
> can trigger with a couple of boost pressure switches. I would like to only
> use one or 2 if possible. Has anyone ever tried using the cold start
> injector to add additional fuel at high boost.

No, no way, don't do it. It's been hashed over time and time again here.
Don't use the cold start valve for fuel enrichment under boost. With the
added boost you have now, your fueling accuracy is even more critical.
Just dumping more fuel in is not the answer, and will most likely lead to
more problems than solutions. You need to either figure out if the CIS
system can be adapted to supply more fuel/less timing to match the boost
you are running, use a 3rd party secondary fuel system to add fuel when
needed, or go whole hog and put a complete EFI system on the car. Trust
me, there's no going back once you've seen what an opened up I5t will do
with a good engine management system and some room to breathe. Javad has
both the summplemental systems, and the full EFI ecu's availible at
http://www.034efi.com . No affiliation, just a happy customer, and the
034's probably have the largest active I5 base around. More info on my
website (in dire need of updating) at  http://www.motorgeek.com/90tq and
our forums at http://www.motorgeek.com The 034IIc Ran my 10vt engine
without even trying, and now it's running the V8 I have in there
perfectly.

>
> I intend to add a granger valve to the computer line to allow me to boost
> past the hard fuel cut at 1.9bar, but I definately need more fuel at the
> top end now.

Ick, you can do that, but if you're already running lean you need to get
that fixed first, then think about running the boost up.



On a completely seperate note..... you gonna be making the Maine Forest
Rally this year? There may be a group of Audi nuts from ME/NH/VT there on
dirtbikes when we're not watchin the races.....


Later!
-Nate
'89 90v8q
http://www.motorgeek.com