problems after Pi motor swap

[rockyracoon]

well the motor swap is done.but I do have some problems.

first of all my cooling fan is not coming on,even if I turn the A/C on.

secondly the car stalls out when I put in gear,this seems to happen only when the car is warmed up.The IAC is brand new (motorcraft)

third,when I hooked up my code reader,and checked the data stream it showed the B1s1 sensor fluctuating voltage,however none of the other 3 have any voltage at all,just all zeros.
the reader shows that the engine cooling temp is 87-90 C which seems about right,so the ECT sensor seems to be working,I thought that may have been the cause of the fan not coming on.

the only code prevalent was P1401 DPFE sensor high voltage,but it seems that the connector was not pushed in all the way,however after I pushed it on all the way the car still was stalling out when I put it into gear.

 

[wmburns]

I had a 1996 that was very difficult to drive after the battery was disconnected. The PCM had not yet re-learned the idle trim values. The car was impossible to drive until the idle re-learn procedure was performed. Alllow to idle one full minute in neutral with the AC off and your foot on the brake. Repeat with the AC on. What is the IAC duty percent?

What is the PCM operating mode (open or closed loop)?

However, if your O2 sensors are not working, the PCM will stay in "open loop". If stuck in open loop, I suspect that the idle trim values are NOT been learned. Which may explain why the car is not learning new idle trim values even after extended driving.

Start by inspecting the O2 sensor wires to the front driver's O2 sensor. Ensure that the connector is fully inserted. Again the O2 sensors that are important are B1S1 and B2S1.

Note, the rear O2 sensors are NOT turned on until closed loop operation begins. So the fact the rear O2 sensors are not producing data is not unexpected under open loop mode.

On the cooling fan, what is the Fan mode as reported by the scanner (off, low, or high)? Also, the ground back from the fan (corner engine bay). Also, there are several small connectors that run under the intake tube. Check that they were re-connected after the swap. Check the several small connectors under the battery tray (easy to over look after engine swap).

 

[fast97gt]

ive just done the pi swap in my 97 this weekend, went off without a hinch, not even a cel, all systems work great and car runs well. my question is did you drill and tap the intake coolant runner of the pi motor to except temp switch for the drivers side sensor, if not then do it. this sensor operates the fan mode regardless of a/c on or not, it works in conjunction of the o2 sensors as mentioned above for the closed loop operation. with this sensor unplugged the fan wont work automaticly and the car will run very rich. if the car being an auto it may have to be tuned?

 

[rockyracoon]

yes I did drill and tap,so youre saying that the sensor I added operates the fan ? I thought that was just for the gauge.

oh one more thing,not sure if it could be related to the fan problem,but I have an idiot light lit for the charging circuit,however the voltmeter in the dash reads good, 14 volt range

WMBURNS so youre saying since im not getting into closed loop the rear O2S will not show any voltage but that doesnt explain why B1S2 is showing no voltage,you think it may be wiring related.
I dont think my reader will show fan information or IAC as well,its a pretty cheap one from evil bay.

 

[wmburns]

Did you re-connect the ground strap from the left hand motor mount to the frame rails?

On your fan problem, the fact that the fan does not come on when the AC is turned on IMO says that it is not a sensor problem.

Check ground G103 front right engine compartment. Check Ground G104 near the battery. Ensure clean and tight. Check the 60 amp Fan fuse in the engine compartment fuse box.

Disconnect the fan connector. Measure the resistance of the black wire back to the battery negative (key off) (post). Turn the key on, engine on, AC on. Measure the voltage at the fan connector to a known good ground such as battery negative (post). Jumper the fan directly to the battery and confirm that it actually does work. The high speed is O/LB and the low speed is R/O. The ground is black.

The idot light is actually a better indication of the health of the charging system. What is the voltage at the battery? What is the voltage at the alternator? Are all of the wires connected to the alternator? Engine ground? Check I/P fuse 18 (20a). Confirm the LG/R wire is connected at the alternator.

Confirm the operating mode of the PCM with the scanner (open/closed loop). Don't guess. O2 sensors generate their own voltage. If no voltage, the O2 sensor is bad or the wiring/connector is bad. Recommend concertrating on getting both front O2 sensors working. Worry about the rears later.

 

[fast97gt]

yes the dtivers side sensor operates the fan etc. the pass side operates the guage. this baffles me, if the car good even ok, when you got done it shouldve fired rite up and ran perfect. im not bragging but mine roled over 4-5 times and wala not one problem.

 

[rockyracoon]

im going to check out the resistance in the fan wiring tomorrow.
in regards to the fan switch that I drilled and tapped for,I dont think it matters but I ended up breaking the one that was in the non PI intake so I just used the one that was in the PI manifold originally on the other side.so I have the green one on the passenger side and the gray one from the PI manni on the drivers side.

 

[fast97gt]

not the same sensor, the pi motor sensor is sending mixed signals to the comp. and could be the cause of the whole situation. because that sensor from the pi motor operates the fan switch, thermostat, etc. its not the same as the npi sensors, so get one to replace the one you broke and see if that may fix it and let us know.

 

[rockyracoon]

I went to autozone .com.and the part number for the sensor is the same for a 96 GT and also for a 2001 gt.

 

[rockyracoon]

ok I got around to checking some things,and I did notice that when the car is up to temp if I remove the plug from the coolant sensor the fan will come on,but as soon as I plug it back on the fan will stop.

the other thing I noticed is that the scan tool says that the fuel sys is in closed loop-fault.

the moter runs pretty smoothe however if I rev it up It pops when I let up off the gas,does that just sound like an exhaust leak,or maybe a miss ?

 

[wmburns]

What are the signals from the front O2 sensors? Did you resolve? If not, this is likely the source of the "closed loop-fault". IMO, the popping is likely cause by the fact the motor is still operating in "open loop" mode.

Possible bad temperature sensor. Note, the PCM knows when the sensor is disconnected. Likely the fact that the fan kicks on is part of the failure mode "limp in". In other words, when the temperature sensor fails outright, the PCM responds by forcing the fan on to keep the car from overheating. Consider getting a temperature sensor that is designed for your application.

It sure would help to ask the PCM what it thinks the coolant temperature is.

Does the AC actually work when it is turned on? Is everything hooked up? Does the compressor clutch actually engage? There is an AC high pressure cut off switch (C128) that if not re-connected looks like it could cause your symptom. C128 is located front center engine compartment. Also check connector C167 located right rear engine compartment on the receiver/dryer.

It sure sounds like CCRM is not getting the signal indicating the AC is on. Was any work done to the CCRM module?

Are all of the grounds hooked back up? There is a ground in the front right hand side engine compartment (G104) used by the CCRM. A bad ground could also cause the fan problems.

 

[patman0911]

If you disconnect the coolant sensor (the one on the passenger side for the PCM) the PCM assumes the car is running hot and turns the fan on to be safe. It may stay in closed loop but it reverts to safer timing and fuel maps, cutting timing and adding fuel to cool down things down.

What temps does the scan tool report? Warmed up it should be somewhere in the neighborhood of 92C/195F

 

[rockyracoon]

the code reader says the engine temp is around 90*C when warmed up.

The A/C does not work I suspect the freon level is low but I will have to verify .

The B1S2 is not reading any voltage.

wm burns, wouldnt the fact that the fan is coming on when the connector is dis connected rule out a bad ground ?

the black wire on the fan connector ohms out at around 54.

the drivers side sensor( ECT) ohms out at around 34 when the engine is warmed up.

 

[fast97gt]

Patman your wrong about the sensor on the passenger side that one operates the temp gauge, has nothing to do with the fan. The deivers side sensor does.

 

[patman0911]

My bad, I did get them swapped around in my head somewhere along the line.

Passenger's side = sending unit for dash gauge
Driver's side = ECT sensor for PCM

 

[wmburns]

the code reader says the engine temp is around 90*C when warmed up.

90*C=194*F not high enough for the PCM to even call for the fan to run. OBTW, are you sure there are no trapped air pockets in the crossover? This will cause the sensor to read low.

How many full heat/cool down cycles since the coolant system last opened?

OBTW, does the car overheat if driven?

The A/C does not work I suspect the freon level is low but I will have to verify.

Reviewed the 96 wiring diagrams. The system is very smart in that it only calls for the fan to run when the AC actually engages. So if low on Freon, the same low pressure switch that keeps the AC compressor from running will also keep the high speed fan from being called for.

Try jumping the AC low pressure on the receiver/dryer. The AC clutch should engage and in a few seconds the high speed fan should run.

The B1S2 is not reading any voltage.

B1S2 is a rear O2 sensor. Please look at B1S1 and B2S1. IMO, the motor will never run correct while remaining in "open loop" (or "closed-loop-fault").

wm burns, wouldnt the fact that the fan is coming on when the connector is dis connected rule out a bad ground ?

Great call! On retrospect, I agree.

the black wire on the fan connector ohms out at around 54.?

54 Ohms from the Black fan connector back to battery negative seams very high to me. Was the key off and the fan removed from the circuit? Not that it really matters as I think if there is a problem it is in the control circuits.

the drivers side sensor( ECT) ohms out at around 34 when the engine is warmed up.

Did you take the measurement with the engine harness electrical connection removed?

 

[rockyracoon]

No I really did not check for trapped air in the x over.

I believe there has been 3 heat/cool cycles.

Im not sure if it would overheat,as I never let it get to that point.

I thought B1S2 was a front sensor.BTW is B1S1 the drivers side front?

I think the key was off when I probed the sensors,the connectors were removed.

I think im going to gonna replace that ECT sensor and hopefully in doing so I will belch the trapped air pocket that may be there. im also going to try and get the A/C running ill probably jump out the psi switch and try adding a can.

 

[wmburns]

O2 sensor numbering

I thought B1S2 was a front sensor.BTW is B1S1 the drivers side front?

The first number is the bank. Bank1=right side. Bank2=left side. The 2nd number is the "function". 1=front, 2=rear.

Therefore:
11=right hand front
12=right hand rear
21=left hand front
22=left hand rear

We regards to the fan problem. Is it possible that you do not have a problem at all? Could you have assumed there was a problem when the fan did not kick on with the AC? The numbers being reported by the scan tool look reasonable to me.

OBTW; 3 full heat/cool cycles should be enough to purge the cross over on a 2V SOHC (assuming the system is tight). Note, the DOHC will not self purge.

 

[rockyracoon]

I think there is a problem.when the engine is first started there are no idiot lights on,but when the car warms up to normal the little icon that looks like a fan will come on. then if I shut the car off for a while and start it back up that light will stay out until I reach normal operating temp.

Im anxious to see what happens when I jump out the A/C PSI switch.I will report back with my findings.

 

[wmburns]

The yellow warning light that looks like a fan is a low coolant level in the de-gas bottle. The level is low enough to cause the warning. As the motor heats up, the coolant expands the level rises. It rises to the point where the warning goes off.

Add some coolant.

OBTW; the float doesn't work as well if the coolant doesn't have enough anti-freeze.