Well I've still been fighting with electrical gremlins an sensor issues. I've been looking into some how wiring in a gm 2 bar map sensor in place of my factory boost sensor since every one that I've bought has turned out to be a paper weight. Would it be possible to put a gm 2 bar in place of a n318 sensor? From the things I've found it might be close in voltage output, but without having one to play with I'm not sure weather it would worth the trouble to swap to a 2 bar or keep hunting for a factory boost sensor.
Here's the specs for a 2 bar - - - V
Manifold Pressure 2 Bar MAP Output
(relative sea level / absolute)
14.31psi / 29.01psi 4.90V
14.00psi / 28.70psi 4.84V
13.00psi / 27.70psi 4.67V
12.00psi / 26.70psi 4.50V
11.00psi / 25.70psi 4.33V
10.00psi / 24.70psi 4.16V
9.00psi / 23.70psi 3.99V
8.00psi / 22.70psi 3.82V
6.00psi / 20.70psi 3.47V
4.00psi / 18.70psi 3.13V
2.00psi / 16.70psi 2.79V
0.00psi / 14.70psi 2.45V
Factory would fall about here
5.00inHg / 12.24psi 2.03V
10.00inHg / 9.78psi 1.61V
15.00inHg / 7.33psi 1.19V
20.00inHg / 4.87psi 0.77V
25.00inHg / 2.41psi 0.35V
29.10inHg / 0.40psi 0.02V

If memory is correct the factory n318 should see 2.0 - 2.5v at 3.9inHg, so would it possibly work?

Where I found the info on the map sensors http://www.robietherobot.com/storm/mapsensor.htm

 

So do you have a full voltage table of the stock 2 bar (Turbo) sensor to compare? Some sensors are nominally labeled as "2 bar" but actually read higher. The FD MAP sensor maxes out around 17psi.

What problems are you having with these used sensors? How do you know they are bad?

 

I wouldn't even know where to start to look for a voltage table for a stock sensor. The used sensors that I've picked up have all been out of specs per FSM. According to FSM at 3.9inHg of vacuum the sensor should show 2.0-2.5v, an all 3 that I've had have been way outside of specs. Plus on the Rtek it always shows 19.5-20.0 on the map sensor when running and off.

 

We've already looked into this. They don't match up.

 

Have you found the code in the stock ECU for the MAP sensor scaling? Then you could just adjust the transfer function and use whatever sensor you want after you calculate a scale and offset.

 

I thought I had a spreadsheet with that data but only found the ATP sensor data so I might be mistaken.

 

So a stock boost sensor would pretty much be my only option then.

 

The ATP sensor is going to have a much different range than the MAP sensor, so if you have it in real values (not some hexadecimal or other machine code) it won't be too hard to figure it out.

 

where do they differ? here ive been using a stock map sensor with my haltech for years. I thought it was a standard 2 bar. from the logs, it seems pretty close to what my boost gauge says

 

Is it possible for the diaphram inside the sensor to be damaged depending on the shiping method, like by air mail or how ever some places like to ship long distances?

 

************************************************** ****************************Plus on the Rtek it always shows 19.5-20.0 on the map sensor when running and off*********************************************** ************************************************** *********************************************

I'd be wondering whey the RTEK does the above instead of looking for another boost sensor. Just an opinion.

 

Yeah I didn't see that originally but Hailers has a point.. It's more likely your wiring/connection to the ECU, not the sensor itself. The ECU will default to a value if the sensor is not there or is out of range. I bet there is an error code for your map sensor.

I believe the FSM has a procedure for checking the voltages at the plug.

 

If memory serves correct you two helped with info when I first started looking into this issue. Maybe I should have sent my ecu to DTI over the winter while I was rebuilding the transmission.

 

WAIT, doesnt our rteks show the MIL codes on them under diagnostics?

 

yessir

 

So if I sent my ecu in to have the 2.1 put into it, would it get inspected to make sure everything is working properly like when they're first sent in? I'm more than comfortable to put the chip in myself it's just to have it checked out to make sure there isn't something wrong with the ecu. An how long would it take to have all this done

 

You can't install the 2.1 yourself.

We do not check out the ECU other than make sure it boots before and after the install. We highly recommend you send us a known-good ECU that came out of a running car or you'll be paying to have the rtek transferred to a good ECU. (It's happened before when people send us untested junkyard ECUs)

Turnaround is typically one business day.

 

I suppose it's none of my business...................but there is NO response from the thread owner in reference to my last post on this thread. I'd suggest reading my last post before this one and take action.

 

turbo2ltr - If I can't install the 2.1 myself then why does dti list one of the options as a self install? The ecu is/was a good ecu when it was in the car, it ran with no problems. The only time the rtek ever showed any error codes was when I first tried to start it an it showed something with the trailing coils, issue ended up being some wires switched around for them.
Hailers - I have no idea what to do next, since all the wiring has tested ok to what fsm an you guys had told me to check.

 

Please show me where it says the stage 2 can be self install.

 

When I remove the plug from the boost sensor on my 87 Turbo car, the RTEK defaults to 15.8.......somewhat close to your figure.

I'd suggest unbolting the pressure sensor and leave its elect plug on it. Then backprobe all four wires in that elect plug with key ON, and see if the BLACK/WHITE wire has batt voltage....................the BROWN/WHITE has approx 5vdc.....................with meter on ohms, the BLACK (might be brown/black on earlier 87) reads less than one ohm................the BROWN/RED reads 2.3 to 2.7 vdc.

IF those read right........go to the ECU's middle plug and backprobe the pin at 2B (still BROWN/RED) and see if it reads 2.3 to 2.7 vdc (it should read exactly what you read on the BROWN/RED in the paragraph above).

All elect plugs should be connected up to their units when doing the above.

I'd also idle the engine til warmed up. Then pull the vacuum line offf the boost sensor and make SURE it's pulling vacuum off the intake. If you feel no vacuum............fix it til it does.

Your 19-20 is offf a bit from the 15.8 I see when my boost sensor is disconnected. The 15.8 sounds like a figure it should default to if the input to the ECU from the boost sensor is not there.

The 15.8 is close to one atmospher or 14.7.

 

t2 - Is this not for the chip or the firmware for the palm? http://www.pocketlogger.com/?pid=s4t2v2update
The way it's listed it makes it sound like it's for the update chip.
hailers - looks like I'll have to tear into my wiring once again.

 

For what it's worth...............I went to my other TurboII and pulled it's boost sensor plug off. It defaults to 20.

My 86 non turbo defaults to .09 which is not related to your car at all. Just FYI for anybody else reading that has a non tubo. Odd 'cause I don't think the Training manual listed that figure for the default.

So I'm saying your ECU is not seeing a connection to the boost sensor on 2B....if series four.

 

Something else that I forgot is this still dont help with the availability of a good boost sensor, cause I've been hunting like mad for a good sensor to no avail.

 

a GM 2 bar map sensor should be very close match. im running the stock boost sensor with a haltech e6k set to "GM 2 bar map" and comparing the haltech readings with my boost gauge, they are identical throughout the entire range. not sure why turbo2ltr says the stock sensor reads different. The ecu even provides the 5V needed by the GM sensors