Lean at idle and rich on throttle, custom VK1000 turbo utility sled

[lshobie]

Hey guys, here is the sled Ive been working on for fun, I'm have some issues and hoping someone here can help me out.

This is a video of the sled running without the intercooler on it.

Ok, so at idle it runs rough, backfires and lean lean on the AFR, like anywhere from 17 to 22. Choke makes no difference - the afr gets better but still runs bad.

On throttle it gets very rich and runs very bad - misfires, and afr is as low as 10. I did manage to get it wound up to 8 pounds of boost on a slippy spot on the floor.

If I remove the intercooler it runs fine, just like normal.

Specs:
-borg warner new turbo, internal wastegate and BOV
-oil pump on separate reservoir for turbo
-fuel pump with reg, i dont have a pressure meter but adjusted it up and down with no difference noticed.

-4 nipples on carb adapters t'd into each other - hose to BOV
-Carb T's on back of carb closest to driver hosed to charge tube with 600 main on it - tried a 300 with no difference.
Carb T's closest to intercooler plumbed to the intercooler.
Fuel regulator hosed to intercooler.

Slides move freely up when blowing in hose.
carbs cleaned with new needles and seat, with aluminum covers and came off a running turbo sled.
running C14 VP fuel


Help would be appreciated.

Thanks!

Louie

 

[RED]

Lets see some pictures of the sled with the intercooler installed.

 

[lshobie]

Ok Ill get some, its the bender air to air intercooler, same configuration - mounted the same as in the RX1

 

[RED]

I watched your video's. Bender turbo's were not very common out west. So I don't know very much about them. But I searched this site & there is a lot of older info about them on here. Typically 100% of the time when they don't run well its from install issue. Did this kit come from the donor RX1 in the video? If so did it run good before? Or did you get the kit in pieces? How is it plumbed? Is the intercooler sending a signal to the fuel pressure regulator? Do you have the restricted orfices installed in the plastic T's?, which then goes to the intercooler.

 

[lshobie]

The kit came off a running RX1. but, i used a different turbo, I used the new borg warner instead and a set of carbs off a working RX1 bender turbo kit.

The reg kits signal from the intercooler.

Does the signal have to be restricted from the t's to the intercooler? I suspect they already are since they came off a running turbo sled.

I've got another fuel reg that I'm going to try today.

 

[givemeaboost]

How long did it sit since it was running last ? These carbs are famous for plugging the pilot jets.


Ken........

 

[lshobie]

It ran at the start of the season - it runs fine with the intercooler off it. I think it has something to do with the float bowl pressure - will try today.

 

[lshobie]

Fuel pressure is 4.5 at idle, I pressure tested from the exhaust side and have some leaks, will tidy those up next week. I'm suspecting the leaks might be throwing off the AFR at idle, I'll tackle the rich spot after that and run it up on the hoist.

 

[RED]

Like Ken suggested, have you cleaned the carbs? Your problem is ahead of the cylinder head somewhere, not behind it. Hard to tell from the video's, is the turbo supported? If not, it would be a good idea to make something up.

 

[lshobie]

Yes the carbs are clean, it runs perfectly with no intercooler on it. The turbo is supported yes. The difference I'm pretty sure is the float bowl pressure, I've got an adjustable pitot so I will try that to see if I can figure it out. The leaking exhaust will explain the high afr reading - but it is still popping and blowing fire out the exhaust once it gets warm.