DFlintstone

What's yours? I'm thinking about just canning mine and putting in a 200 ohm resistor. Thoughts?

DFlintstone

Guess you can't back probe it running, at least not with my meter. Longer story shorter, it was about 19K starting out. It settles around 550, 650 running/ operating temp. Sitting hot, as the heat migrates to it, it drops down to the 400 range, was even hitting 3 something when I came in.

So because of the dynamics of the air flow, it never reports operating temp to the ECU, running. I suppose they designed for that?

Here in the fourth one down it has the chart..https://www.cherokeeforum.com/f51/he...ix-links-1397/

Radi

What results are you hoping to achieve by replacing it with a resistor? Is the sensor bad?

cruiser54

What did you do? Cook a fish on your intake manifold heat shield one time?

But yeah. Why?

Bustedback

I relocated mine to the air cleaner housing, it stays cleaner there and gets a more accurate air temp reading than in the intake manifold, I also noticed a very slight performance gain.

offroadordnance

IAT is used inconjunction with MAP sensor in a speed density based system to calculate airflow and adjust correct injector pulse width. You might screw up A/F and maybe damage the cat, burn a valve, etc putting a fixed resistor in there.

Edit: By fixed resistance I'm referring to the 200 ohm resistor the OP wants to replace his IAT with. Relocating the IAT wont cause the potential issues mentioned.

Bustedback

I checked the fuel trim before and after the relocation and did not notice any change. The injector on time is the same as before too.

DFlintstone

I make allot of short trips and am hoping to do anything I can to bump my mileage up. I want to at least rule out that this thing isn't missleing me!
With the coolant running into my bottle at 194*, with the engine running the resistance was up over 550. 185 @ 212* and, 450 @ 160* are the specks. So right now, it's "reporting" temps well under 160*, while my coolant is at temp. I didn't think to bring it in and put it in water with a candy thermometer. Sometimes one little thing turns out to be "the ticket"..Idk. Maybe I'll brush up on my resistor color codes and do an experiment.


Close! , a lizard. (I even make my own Salsa). All my tools, chainsaws, generators, latters, everything even small stuff here, has that paint mark.

OK...so maybe it's a little cooler there, giving you plenty of fuel...

Good point....I don't think I'll worry about my cat, but if I WERE to end up too lean I suppose there could be a valve issue. Up at temps that might burn a valve though, I'd hope it would be down at lower resistance anyway.

Interesting...yea, I had wondered about that. Inside the manifold, surrounded by hot metal it's exposed to the radiant heat there, where out in the plastic you might think that would be less.

Well it IS functioning. it would be nice to know what someone getting 18+ MPG is seeing from it. I just got off the phone with my Napa (to price it), they couldn't find it.

I was partly fishing to see if someone would pipe up, "it's toast dude!", your numbers are too high!

jakbob

the IAC has been discontinued if i recall correctly.

another thing... why would the air in the intake be as hot as the coolant? i know air absorbs thermal heat pretty fast but i wouldnt think the air in the manifold would be the same temp.

DFlintstone

Yea! Darn good point. Just because it shares a chart with the CTS, doesn't mean it should read the same. I had seen this thing routinely get over 20 mpg, and now 16 is more normal. I'm being somewhat methodical, gradually going through trying to see if I can find something...without missing something. CTS is next. (a little more straightforward, being IN the coolant)

cruiser54

Relocating the IAT to the air cleaner housing does give a small boost in power and no loss in economy. I think it will probably live longer in that environment.

Don, the use of oxygenated fuels in summer blend gas could cause your fuel mileage drop. Check craigslist in your area and see if you can find a Yugo for those short trips.

DFlintstone

Yea, it's the darn law. I can see paying regestration for a car that just sits, but it burns me I have to pay insurance when I can only drive one at a time. Another $300/year, insurance (+registration), and I'd drive my 74 Celica.

I have my old 750 Honda, for sunny days anyway. ($75/yr insurance, $81! to DMV.)

It's raining, and my Jeep is sort of drippy even when it isn't, but I'm going after the CTS right now...

I'd thought maybe SOMEBODY, might have checked their IAT.....

DFlintstone

What's yours? ( Renix IAT resistance? Went at the COOLANT sensor. With the frame up, axle hanging, STILL! sheez. Plenty difficult. I found a "fat 1/16th", nail, would fit snugly enough, into "pins" on the sensor connector. I suppose it might not be imposable to hold regular probes in there, and read the meter, while getting meaningful readings, but I put alligator clips on the nails in the connector. Then I watched it.

Started out very high , 38K or so. It dropped down under 400 soon enough. Here is the catch. It would bottom around 315, then cycle up to 380, then back. The thermostat fluctuating I suppose. So that's not "in spec". I didn't specifically check here, but this (same meter, $20 HF), does therm's, and I'm getting a consistent 195*.

Rockauto shows $20 to $60......For a CTS. Without making a graph from the temp chart, I can see my numbers are high for 195*.

Guess since nobody here with a Renix Jeep knows the resistance or any of there temp sensors, I could just go buy a new one and run a few tanks through there and see if it helped. Lol!

Maybe I'll just put 200 ohm resistors on them both! (my first 10 minutes is usually steep down hill)....

Radi

Ouch.
I drove one of those things when they first started appearing here.
It was the *worst* vehicle I have ever driven, before or since. And I've owned a Pinto Wagon. With woody sides.
Q) Why do Yugo's have heated rear windows?
A) To warm your hands while pushing it.
Q) Did Yugo's have an anti-theft device?
A) Yes. The nameplate.

DFlintstone

HA! We finally put the "3rd generation" engine in the Vega GT hatchback. With the right sleves, AND, (crucial), the added coolant passages right up by the gasket, it still sit's here with 206K on it. (GF melted it with a blown heater hose), "I was only a mile from home when the light came on". That mile climbs almost 1000 ft...