Curious Diagnosis and Intake Tubing Question

[JFBrink]

Hey, there,

I've been driving my swap around a bit, now and then, but all the trips had to be short, as it would stall out once it got to temperature and the fan turned on. I haven't had a lot of time, but I've been slowly checking possible problems: bad ground or power connections, bad relays, bad temperature sensor, bad fan motor... I had basically run out when, one day during testing the problem seemed to go away.

After 4 successful fan cycles, I thought "hey, great. it cured itself." But as I was putting down the hood, it happened to enter another fan cycle and the car stalled. Okay, hood back up, another cycle with no problem. Hood down again, stall again. Fan on: hood up, hood down, hood up, hood down. The HOOD was stalling out the car! As I was checking for mechanical or electrical interference around the hood, my MAF caught my eye.



It's temporarily mounted with some JY tubing and no filter, sitting more or less even with the face of the radiator on the passenger side. In an a-ha moment, I slid my hand slowly over the intake and it stumbled just like it did when the fan turned on. So, I fabbed up a quickie deflector, to isolate the MAF inlet from the front of the radiator & the problem went away.

So, it seems that the air rushing laterally past the MAF into the radiator was going too fast for the engine idle suction to pull it in. Wild.

My question is: Does anyone have a good, cheap source for new intake/turbo hose/tubing? The best I've found is http://intakehoses.com

Thanks,

Jesse.

[Kevin Desirello]

Hey Jesse,
Yes the cooling fan is causing turbulance in the area you have the maf located.
looks like in the pic there is and open nipple on the hose from the tbody to the maf.
This could also be causing you some problems.
If it is not plugged it will suck unmetered air the ecu will not account for and stall the engine.
You may have a combination of problems with the hose and the fan causing turbulance in the maf.
You could put a 90 degree hose or pipe on the maf and route it to the left of the car and then put a good k&n filter on it this should cure your problems.
If not you can then build a shroud behind the filter to deflect the draw/turbulance from the fan.
Any good muffler shop can get you some mandrel bent tube or sorce out some siliconehose.
I have had good luck on ebay just type in turbo hose.
Hope this was some help.
I have done several sr20det swaps if you would like to talk on the phone pm me and I will give you my number.
Are you going to the JCCS show
See Ya Kevin D.

[JFBrink]

Kevin,

Yes, the turbulence was definitely the problem.

The photo is old: that nipple was plugged before the car was started & I installed a shield yesterday that protects the MAF from the effects of the fan & it works great.

Thanks for the eBay tip; that didn't even occur to me. Everything I was looking for is there, cheaply.

Best,

Jesse.