240: penta swap issues

[swedishK]

I have a 2.5L penta block underneath a b21ft head (t cam), running turbo LH2.2, turbo breakerless, 19t and redtops.

it feels like the physical timing is off, no power under 2k, then it wants to boost hard. if i put my foot down over 2k, it'll start bucking over about 5psi. i've tripled checked the timing belt, and as far as i can tell, everything is lined up right. if i drive immediately after starting, it will feel normal for maybe 30 seconds before it starts behaving this way. it will also idle very smoothly initially, but after driving it will start to rev between 400 and 1200 rpms.

not sure where to start before firing the parts cannon. i feel like i'm missing something obvious.

[VB242]

What are the red tops rated for flow wise?

[swedishK]

315cc/min according to fcp.


Edit: it wouldn’t build any boost on the drive to work today.

Update: WG actuator rod came apart

[VB242]

I was running brown tops with lh2.2 they are about 367 cc/min.

[culberro]

Double check ignition timing.
Then do a boost leak check.
Then check fuel pressure (I had a tear in the intake hose that caused all sorts of weird running issues that were not consistent.. not even with the fuel tank level)
Then check MAF.
Then check coolant temp sensor.

[LC4CARL]

It's often convenient if we can go back to the last change when things were ok, but this sounds like a major update.

You wouldn't happen to have an AFR gauge would you? Not sure how long the cold start enrichment stays on, but the fact that it seems to run better with more fuel is interesting.

Turbo spins freely?

Idle surge is interesting. I have green tops on my 10 psi, B21FT.

[MrBrown]

Don’t laugh but mine did this same thing. Guess what it was? A rag in the inter cooler piping I forgot to take out when I was working on it. I would have never believed it. When someone suggested to look, I wasn’t even offended at that point. That dude was right.

All I am saying is try and check the piping and see if something is in there you may have forgotten and sucked in.

[sbabbs]

Yeah sounds like big air leak. Does it run real good with no boost at all or same thing, runs bad? Unhook wastegate so it stays open and drive it around see if it does the same thing. IF it does then run great maybe it is spark blow out with the boost.

[swedishK]

Update:
I am certain there are no vac leaks, I’ve tried a few different 007 AMMs (including a programa reman which prevented the car from even starting(would NOT recommend)), new o2 sensor, AEM wideband, just did the fuel filter and swapped in a kjet main pump, already have the ipd intank upgraded pump, newish FPR. Still behaving the same way. The idle is more consistent now. Wideband shows 14.7 on startup, but quickly and smoothly climbs up past 17 to show ———. So either I have a bunk wideband, or I’m leaning wayyyyyy out even at idle. Are my injectors simply too small for a 2.5L? Or have I done something else stupid?

[Harlard]

What kind of shape is that wiring harness in? I have had pins that would back out when installing connectors, which would cause all sorts of weird problems tvery similar to what you describe

[ZVOLV]

Originally Posted by Harlard

What kind of shape is that wiring harness in? I have had pins that would back out when installing connectors, which would cause all sorts of weird problems tvery similar to what you describe

Ha, that is a problem I sometimes see on NEW cars that I work on.

I have the special tools to DRAG TEST for loose terminals.

[swedishK]

Update:
Played with ign timing, and it feels much more responsive out of boost. But now I get det around 3-5 psi. Put in a new sensor, and the WB actually reads now. Running stoic at cruise, leans out on light accel, will run rich when I put my foot down hard, but still det at low boost. Current plan is bigger injectors (440cc) and ezk. Anyone have any better ideas?

[Harlard]

Microsquirt

[swedishK]

That is a better idea. But also more money and work. Gonna try this first unless there’s a good reason not to.

Perhaps the breakerless dizzy diaphragm is bad and not getting retard under boost? I do have a spare turbo breakerless dizzy. Try that first?

[sbabbs]

Welp there is always a chip for the 2.2 fuel ecu and chip for the 2.2 ezk if you wanna go that way instead of the brokeless distributor. You can even program your own ignition curve if you want..

http://forums.turbobricks.com/showth...ighlight=simon

http://forums.turbobricks.com/showth...ighlight=simon

http://forums.turbobricks.com/showthread.php?t=268066

[swedishK]

Might take you up on the ecu chip. Need to see which box I have.

[swedishK]

installed some 440 injectors today. much better afr numbers, 11-13 under boost, but still getting det at low boost. so probably ignition right?

[Harlard]

Could be overadvanced ignition, could be oil getting into the combustion chambers

[swedishK]

didn't think about oil. might be it.