I need to know at what temp does a 95 xj go into closed loop? I need to know exactly or if you know what the coolant temp ohms is, that would work too. I need to force my ECM into open loop from my Hobb switch. I tried using the TPS voltage which works but it also forces a downshift.
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closed/open loop coolant temp?
- Thread starter CSaddict
- Start date
I've been monitoring CL/OL transitions with other OBD2 data such as fuel trims, rpms, map, but not with coolant temp. I'll check it out, but it'll be from a 96. I need my OL to start at 2700 instead of 3000+/-, so I can richen up the mixture, so I've thought about forcing it into OL.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
How?
- Location
- WA state
Typically you can wire in a resistor which makes it read a lower temp. A lot of times they are wired in with a switch so you can turn it off.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
That won't do what he intends to do. He wants to change the RPM it changes from CL to OL, not keep it thinking it is in CL.
I haven't come up with a game plan yet. I'll monitor tps values while monitoring rpms and cl/ol transition and hopefully determine a tps value where the pcm goes into ol. I will then want that tps value to be happening earlier, which will mean modding the tps values(I hadn't planned to modify the cts values as CS is intending). It's too bad the psc1 can't modify two signals at once, cause that would be the easiest way to mod the tps values.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
That is one thought I had, modifying the TPS signal. However, you couldn't use a simple device such as a Map adjuster. You would need something that would jump the out put ar certain RPMS. As you said the PSC1 would work if it could modify two different signals. Using another device similar, but simpler such as an Apexi is one idea. However, if you have an automatic transmission I don't know how it would react to such a mod. There maybe more drawbacks that I can't think of though. When I frequented JU there was a member that used an Apexi to modify the O2 sensor values and he reported good results. I don't see how that would work though, and I wouldn't consider his mod and findings concrete.
-Chris
-Chris
I know how it reacts. I have a hobb switch that bypasses my TPS when in boost and sends a modified signal through a rheostat back to my ECM that simulates WOT. The problem is that my truck then wants to downshift. I am now planning on bypassing the ECm control of my AW4 and making a shifter with switches to control the tranny and converter lock up.
The TPS trick works. I know because we also run the same setup in my buddy's turbo wrangler that is a 5 speed and it works great. I just need to get it to work in my turbo Cherokee with the automatic.
I had an APexi AFC in my truck with the first turbo set up. You can not get it inline with the factory map sensor at all. Anyway the stock MAP can't read boost so its useless anyway. Its not compatible no matter the settings. So I took it out and my 36# injectors and went back to a stock injector with an FMU and a booster pump.
The TPS trick works. I know because we also run the same setup in my buddy's turbo wrangler that is a 5 speed and it works great. I just need to get it to work in my turbo Cherokee with the automatic.
I had an APexi AFC in my truck with the first turbo set up. You can not get it inline with the factory map sensor at all. Anyway the stock MAP can't read boost so its useless anyway. Its not compatible no matter the settings. So I took it out and my 36# injectors and went back to a stock injector with an FMU and a booster pump.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
I figured it would do somethign stupid like that
I and others run the Apexi devices with out issue. I have an SAFC II and it works fine. Perhaps your in and out setting were incorrect? Doesn't matter any how as it isn't the best for a forced induction application. The hardest part for my install was finding a RPM signal wire (98+ don't have a tach signal going to the dash)
What was your in/out? I couldn't get it mimic mine exactly and well it doesnt work in boost anyway. (I'm a Honda guy and our stock map sensors read up to 11psi roughly.)
It was weird monitoring the ol/cl and cts during warm-up: It kept switching from ol->cl from 50*C until it hit 85*C(185*F), when it stayed in cl(I'll have to check again, as the lm-2 could've been acting up with the new obd2 info I requested from it). Dunno if that helps, but makes me leery of having a 180* t-stat in there(I had one in there prior to the stroker, as rec'd by Jet for the stage2 chip, but now it's a 195*).
So after the previous post, I went and hung out w/ a friend for a little over an hour. I restarted the Jeep and it was reading 55* and was in cl already, so that further confirms my sketchy feeling about the results from the previous post. I'll report back with the results from tomorrow's warm-up. . .
Edit: I replaced my gauge temp sender a while ago and noted that the temps stayed a little to the right of the 210* mark(whereas it was a equally to the left on the old one--no biggie, just noted/referenced). This ~215*F on the dash is 86*C(187*F), according to the lm-2 that is scanning the pcm. The cts has tolerances as well, so can actually be +/- that, but is definitely more accurate than the sender/dash gauge combo, .
Edit: I replaced my gauge temp sender a while ago and noted that the temps stayed a little to the right of the 210* mark(whereas it was a equally to the left on the old one--no biggie, just noted/referenced). This ~215*F on the dash is 86*C(187*F), according to the lm-2 that is scanning the pcm. The cts has tolerances as well, so can actually be +/- that, but is definitely more accurate than the sender/dash gauge combo, .
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Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
IIRC it was 01 to 01... but I have also heard 13 to 13 works on the older rigs.
wahoo50
NAXJA Forum User
- Location
- Eufaula, Al.
Am curious if you figured it out. I have also turboed my XJ, at zero inches of mercury, the motor starts bucking off and on. So I know I need to address the MAP. I also added a 7th injector plus have added alky. Runs good only need to get past the cutting off part. Got any ideas for me?
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
Do you have a wideband? Any piggy back computer? what MAP sensor are you using?
wahoo50
NAXJA Forum User
- Location
- Eufaula, Al.
No wideband or piggyback. Just factory ECM. Turbo and most other parts came off my Grand National Buick, am using a 3 bar MAP for activating my alky. The original factory 1 bar is still connected to the engine. I do have a MAP adjuster I could install if it would help. Thanks for your reply.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
The stock map bar won't tell the PCM that there is pressure and to add more fuel.. it think you need to smooth things out with the PCM with a piggy back from there before you destroy your engine. A MAP adjuster will do you no good. You need a piggy back and a MAP that can detect pressure to feed tot he ecu to feed more fuel to the stock injectors and keep the PCM happy.
What it seems to me that you PCm is doign is having an issue with teh MAP and cuttign the stock injectors off.
What it seems to me that you PCm is doign is having an issue with teh MAP and cuttign the stock injectors off.
