my LeMons car

[KPLAFIN]

Originally Posted by Joe Perez

The 24 Hours of Lemons can be a somewhat rough-n-tumble endurance race. You remember the final scene in Mad Max Beyond Thunderdome?

I'm guessing they're putting it there to keep it out of harm's way, as a busted radiator due to a front-end collision would pretty much end your day.

I can only imagine how un-goddly hot it's going to be in that car for an extended period with the rad ~1 foot from you. Guess you have to make sacrifices though...

On a side note....should I be embarrassed that I've never seen Mad Max?

[eyesoreracing]

Have you ever been to Thunderhill in December? Our car will be the most comfortable place for 100 miles in any direction.

-D

[eyesoreracing]

Fired her up for the first time today. No turbo at first, onaccounta I got the wrong thread pitch for our turbo oil line fitting.

Click on the fireball for a video and at least a little sound...




I think the little white sparky things in the fireball are dead spiders. The exhaust spent the last 4 years in the back yard...

-D

[JKav]

Here's what the exhaust looked like after it was dug out of the backyard, a small pile of dirt shaken out, and installed:

[JKav]

One thing we noticed while running the engine for the first time--during warm idle, the idle would intermittently drag down every few minutes, and then recover, like some big load just switched on.

Electrical accessories are minimal on our car. No HVAC, just the gauge cluster. Its not the radiator fans cycling on and off because we installed a switch override and were running them constantly. Stock 1.6 ECU, injectors, etc. Harness is from an auto trans 1.6; we now have a 5spd manual.

Any ideas on what to check?

[hustler]

Originally Posted by JKav

One thing we noticed while running the engine for the first time--during warm idle, the idle would intermittently drag down every few minutes, and then recover, like some big load just switched on.

Electrical accessories are minimal on our car. No HVAC, just the gauge cluster. Its not the radiator fans cycling on and off because we installed a switch override and were running them constantly. Stock 1.6 ECU, injectors, etc. Harness is from an auto trans 1.6; we now have a 5spd manual.

Any ideas on what to check?

o2 sensor open/closed loopage shenanigans?

[eyesoreracing]

Originally Posted by hustler

o2 sensor open/closed loopage shenanigans?

Well it was all happening at idle, so that seems unlikely. Unless there's some strange open-loop idle thing I don't know about.

-D

[DragonsMaw]

Originally Posted by eyesoreracing

Well it was all happening at idle, so that seems unlikely. Unless there's some strange open-loop idle thing I don't know about.

-D

I've got the same thing with a stock car and also no idea what's going with it. My plan is just to go standalone and see if it still happens.
Or swap engines.

What did you guys end up deciding for engine management?

[eyesoreracing]

We've got a fuel pressure regulator and a magic spark box. Tomorrow we try it. Wish us luck...

-D

[eyesoreracing]

baseline run, no turbo. First time this pile of parts has done anything under load. Not bad at all.

[eyesoreracing]

Much progress...

Little things, like the oil feed line, finally.



And the downpipe support brace (Hood hinge on the engine side bolts to a parking brake cable bracket on the exhaust side)

[eyesoreracing]

And the big exciting things, like this intercooler. It came from a blue car.

The inlets and outlets weren't where we wanted them, and we have no aluminum welding skillz, so we gave it to a homeless guy to weld for us.



Then we used some of these



and some of those



to put it in the car.

[eyesoreracing]

Words are unnecessary...

[eyesoreracing]

And now the problems...

1: pinhole leak in the brazing where we attached a -4 AN fitting to the stock Mexican Dodge oil line. Observe wet frame rail and active mopping operation...



2: Wacky fuel pressure.
In naturally-aspirated form, the fuel pressure was running a near constant 47 psi. it should go down with manifold vacuum, but it didn't. It waggled around a little on transients, but didn't really behave correctly. A/F on the dyno was still a happy 13:1.

We noticed the periodic idle stumble a couple of times, but not while we had the fuel pressure gauge hooked up. We're starting to think there's a relationship...

At one point (still before the fuel pressure gauge) the car died, and there was this strange thump-thump-thump-thump sound coming from under the car. Just before I turned the key off, Sarah spotted the fuel line pulsating in time with the noise.

Periodically there's a strange low buzzing noise that sounds like its coming from under the dash (only audible from the driver's seat) that corresponds with weak fuel pressure and a familiar idle stumble. I can best describe the sound as similar to bubbles rushing through a small, orifice. Yea, I know, no hydraulics or fuel lines under the dash, I'm just sayin that's what it sounds like...

And, with the turbo in place, (and a bipes box installed and possibly wired correctly), fuel pressure drops to nearly nothing (10-20 psi) and the car dies as soon as it sees any load (like trying to pull off the lift and drive over to the dyno)

Now that I'm fed and watered and sitting comfortably on my ass, this all clearly points to the fuel pressure regulator. Probably operator error. Anyone know which way the fuel flows in these things? I assumed it flowed out of the stock regulator, into the center of the vortech, out the side of the vortech, and back to the tank. Did I do it backward? Seems like that might explain a lot of what's going wrong.

-Dave

[eyesoreracing]

Yup. That was it. Just looked up some instructions for a Vortech Mustank supercharger that uses the same regulator. I got my in and my out mixed up. Things should run better tomorrow...

101hp ain't bad with your fuel pressure regulator hooked up backwierd!

-D

[samnavy]

Hmm... I've been saving this one for a special thread.

[curly]

sigh...when I sold you that vortech, I was hoping it would go to good use, not be installed incorrectly.

kudo's on the intercooler though, keep us posted on fixing that leak, I'm thinking goobs of jb weld

[eyesoreracing]

I guess you should have thrown in instructions for another $5...

fuel pressure regulators for dummies.

-D

[turbobluemiata]

I really like your purple vacuum tubing

[curly]

read the greddy turbo faq newb! haha! omg jk hic lolz hic...