cal questions

[shelby zed]

im running a cal with a 21 psi cutout and its running 16 psi right now, under boost or part throttle i get check engine light, codes are 12 23 33 34 and 55, checked ais plugs and they are good, any ideas?

[cordes]

Have you checked the charge temp sensor yet?

[moparzrule]

Yup the code 23 (charge temp) is your issue. The 33 and 34 won't affect how the engine runs, but the 23 will.
You'll have to get a new charge temp sensor from a vendor, don't get one from the parts store because they give you a coolant temp sensor which is made of metal and will heatsoak bad. The stock one is made of plastic-
http://turbosunleashed.com/shop/product_info.php?cPath=67&products_id=255

[shelby zed]

it is a new one however its from a parts store. it didnt do it before the cal, is that normal?

[cordes]

it is a new one however its from a parts store. it didnt do it before the cal, is that normal?

Check the resistance across the pins of the CTS to see if it is any good.

[moparzrule]

I've had ones straight from the parts store that were bad. But regardless, having a coolant temp sensor in place of a real charge temp just doesn't work well.

You can also verify the voltage with the key on-
0 deg = 4.70 volts
20 deg = 4.47
40 deg = 4.11
60 deg = 3.67
80 deg = 3.08
100 deg = 2.51
120 deg = 1.97
140 deg = 1.52
160 deg = 1.17
180 deg = .86
200 deg = .65
220 deg =.48
240 deg = .35
260 deg = .28

Here's the coolant temp range-
Coolant Temp Sensor Response Chart
110 degs = 4.20 volts
120 = 4.00
130 = 3.77
140 = 3.60
150 = 3.40
160 = 3.20
170 = 3.02
180 = 2.80
190 = 2.60
200 = 2.40
210 = 2.20
220 = 2.00
230 = 1.80
240 = 1.62
250 = 1.45
Temperature to Resistance
32 degs = 30 - 35 K ohms
77 degs = 9 - 11 K ohms
212 degs = 640 - 720 ohms


As you can clearly see, the coolant temp sensor is different voltages than the charge temp, not even close actually! Yet the stupid parts stores give the same part number for both....:mad:

[shelby zed]

sorry i was asleep when i replied, i thaught you said coolant temp not charge temp. my car doesnt have a charge temp sensor but i guess the cals probly do, any way to eliminate it?

[cordes]

What year electronics and cal?

[shelby zed]

89 and 89

[moparzrule]

Why not just add it? It's 1 wire into the large connector.

[cordes]

I agree that it is pretty easy to just add it in. However, I believe that you can take the CTS tables down to zero if you don't have one. I have read that this is what the factory did for the non-CTS enabled cals.

[moparzrule]

If you are burning your own cal there's a table down there to disable the charge temp anyway.
Even if you don't want to drill/tap the manifold on the car for the sensor, just hook up the wiring and let the sensor dangle in the engine bay. No harm done.

[risen]

As you can clearly see, the coolant temp sensor is different voltages than the charge temp, not even close actually! Yet the stupid parts stores give the same part number for both....:mad:

The resistance of the 2 sensors is the same at a given temperature as they are the same sensor internally. This has been repeated to me many times over. The 2 sensors do have different casings, as you previously pointed out.

Now, the voltage drop is different for the 2 sensors due to the bias resistors being used. Also, if you were to test in-car, there is a point where the coolant temp sensor has it's bias resistor swapped out to "increase" the range of the sensor (I believe it's around the 110 degree mark).

[moparzrule]

The resistance of the 2 sensors is the same at a given temperature as they are the same sensor internally. This has been repeated to me many times over. The 2 sensors do have different casings, as you previously pointed out.

Now, the voltage drop is different for the 2 sensors due to the bias resistors being used. Also, if you were to test in-car, there is a point where the coolant temp sensor has it's bias resistor swapped out to "increase" the range of the sensor (I believe it's around the 110 degree mark).

Sooo what was the point of your post? OK so they are the same, but not the same? LOL

If they give off different voltages at the same temp then they are not the same to me, and should not be used in the same application of charge temp and coolant temp.

[risen]

Sooo what was the point of your post? OK so they are the same, but not the same? LOL

If they give off different voltages at the same temp then they are not the same to me, and should not be used in the same application of charge temp and coolant temp.

False.

The bias resistor is in the LM/SMEC. Keep that in mind and re-read my post.

[moparzrule]

False.

The bias resistor is in the LM/SMEC. Keep that in mind and re-read my post.

Ahh, now it makes sense.

OK but even still, I definitely don't agree with having the charge temp sensor made of metal, heat soaking very badly and giving false readings. So use the factory Mopar plastic one anyway!

[shelby zed]

ive heard of drilling and tapping it while its on the car using a vaccum? anyone done this?

[moparzrule]

The little pieces of aluminum wouldn't hurt anything anyway. They will blow right out on startup pretty much, in and out.

[Tony Hanna]

If you're worried about it, just mount it in your upper intercooler pipe instead. Easier to take off than the manifold, and you can be sure you've got all the shavings out.

[moparzrule]

If you're worried about it, just mount it in your upper intercooler pipe instead. Easier to take off than the manifold, and you can be sure you've got all the shavings out.

Yup, plenty of people have done that too.

[t3rse]

Those little bits of AL will ---- ---- up. Put it in the charge pipe or let it dangle.

[moparzrule]

Those little bits of AL will ---- ---- up. Put it in the charge pipe or let it dangle.

I've done it 3 times already there big shot. So what do think it will do?

I've had a lot worse things go through an engine than bits of aluminum too.