legacycentral bbs

OK kids....

Its 7:45 pm. The hood is up.

I am pulling my old intake manifold and swapping in a ported manifold with a knife edged throttle body valve.

Trick is that I have to swap over EVERYTHING off my old manifold onto the new.

Start your watches!

Yeah, I am taking pictures.

Here is what I did.

Kelley and Brydon polished it to start.



Then I ported the throttle body area manifold trunks

Its off.

Ready to swap parts

manifold stripped

Not fair... I want a place I can work on my car at this time of day.

wiring, gasline and what not swap complete.




Now knife edging the throttle body butterfly valve.

ok, issues have started. meaning, I am swearing and ran out of Sparks.

solution

get more Sparks and swear more while not touching anything.

reason #? for wearing glasses.

Gasoline in the eye.

IT LIVES!!!!


But....

The IAC from the 90 NA manifold and the ? turbo manifold are different ....2 versus 3 wire.

so it doesnt idle worth crap.

But it does drive....

You've got some of the oddest shit in your car I've ever seen, but it's cool as hell.

Back from the test run to my favorite bar and back.

First off, the butt dyno says +20 hp. No shit. But then again, it is a butt dyno. But it does seem to be faster than it was.

But............
.......
....
..
.
It does not like to idle very well. I suspect the main factor in this is the fact that I swapped over a 3 wire into a 2 wire IAC. I cut the wire that wasnt used on the 2 wire, but I really havent had time to play with it.

Also, while on boost, it sometimes cuts out for a split second, then come back on. And not a full second, thats along time, just a 1/10th of a second or so.

But all in all, the motor is a lot stonger it seems.

I need to check ALL my vacumn lines, all my wires and what not in actual good daylight!

Bang!

Oh yeah, I have pictures for all my posts. I will update tomorrow.

sounds like fun. gotta see those.

For sure post the pics when you get a chance.

I'm ripping off my intake manifold today. I doubt your record will be in jepordey!

Wait -- you switched from[i/] a 3-wire IAC valve to a 2-wire IAC valve?

I thought 90-91 5MT NAs came with 2-wire valves stock.

If it is in fact the other way around, I might be able to help you with a little wiring that might make it more workable. But why not just switch your original valve over to the new manifold?

No, I HAD a two wire IAC. But the new one is three wire. BUT the harness has three wires no matter what. So I cut the third wire in case it did something it wasnt supposed to. But I will splice it back together if neccessary.

And why didnt I use the old IAC valve? Because location of the actual hole on the turbo manifold is higher than the NA manifold and is not modifiable (read as grindable). So for the moment I am stuck using the 3 wire IAC from a 1991 NA Automatic.

Ah.

Okay.

Hm.

To know exactly what to do, I need more information. In particular, I could really use the "Engine Electrical" diagram from the FSM's "Wiring Diagram and Troubleshooting" section. Maybe PM Josh to see if he has time to see if he has a copy?

But failing that, here's what I say to do:

Start the engine and let it warm up.

Disconnect the IAC valve's electrical connector.

Only the two outside wires of the connector are used, right? Use a voltmeter to figure out which one of these has +12v on it at all times. This is the "hot" wire.

Shut the engine off and disconnect the battery.

Swap the "hot" wire with the middle wire of the connector. If you use a flat-blade jeweler's screwdriver you can actually release the contacts from the connector and then stick them back in in the opposite positions.

Hook the battery up and try starting the car. It won't run right, but it should run okay, with a higher-than-normal idle. If not, try swapping the outside two contacts of the connector (leaving the "hot" wire in the middle) and try again.

Then report back.

OK, went out to check over all my vacumn lines. THEY were fine, but I did find that I FORGOT to put the hose back on the IAC valve! HAHA, thats what you get for drinking Sparks and spashing gas in you eye!

Anyway, this new IAC valve has a larger hose outlet than the old one and so my current hose wont fit so I was unable to fix it in the driveway.

And on another note, I started the wagon and it idle, but not great of course, and I unplugged the IAC valve and BAM, dead. So it does work somewhat. Lets hope actually plumbing it in helps!

OK, some good stuff and some problem stuff.

Good stuff first.

It runs! It has more power (butt dyno proof only). Better throttle response. Looks cool. Idle is acceptable because it is better than worse.

Problem stuff second.

Idle is not acceptable because it should be better.
I am now running leaner than before AND I get a weird horrible miss while just cruising and sometimes while on boost which IS NOT SMT6 related. The miss I am pretty sure is fuel related because whenever I miss while cruising, the Perfect Power program shows me spiking lean.

Now this could be possibly due to the fact that maybe, just maybe, I have the fuel injector clips reversed. I neglected to mark them when they were removed, so they may or may not be on the right injector. I don't have my manual at home so I cant compare wiring colors. Poop.

Try my suggestion about the IAC valve wiring.

As for injector clips matching, just unplug one of them with the engine running, and then see which trouble code the ECU throws. If you unplug #1 and it throws a code for #3, you got them switched.

I will do both. Thanks

Oh Yeah, I "adjusted" my idle for now by just cranking the IAC valve all the way around as far as it would go to bring the idle down. While not the right way, it works for now. About 900-1000 rpm versus close to 2000.

I milled an adapter plate out of 3/16" aluminium and installed the old 2 wire IAC. At first it still idled 1500-2000. Then a day or so of driving later, it dropped down to 1000-1200. Now it regularily idles at 800 or so. It might have just took the ECU some time to learn the new air flow.