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2001 Deville
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37 Posts
Discussion Starter #1
I did rear valve cover and manifold gaskets drove car around about 15 minutes cars started surging bucking and reving extremely high i checked pelleum for vaccum leaks none put new maf and map sensor P0101 keeps returning with high idle
 

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2001 Deville base
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26 Posts
A good place to start would be to look at the wiring harness for frayed/exposed wires. I had to install a new connector to the MAF and splice the wires because some of them were exposed. I did it with a crimping tool but you can use heat.
I would also clean the connectors with electronic connector cleaning spray. If all parts checks okay, it might be an electrical problem.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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67,158 Posts
As posted, P 0101 points to MAF performance. Make sure there are NO air leaks into the intake ducting at or after the MAF.

Also, check the vacuum systems for leaks, when was the last time the TB and IAC were cleaned ? If the PCV dirty air line is broken/cracked that's a large vacuum leak directly into the intake manifold, passenger end tunnel.

Intake manifold bolt torque is only 7.5lb/ft - hope you did not crack a port bolt boss -

Here's your vacuum diagram - click to enlarge, use the < > to scroll - click the little grid bottom right to see the full pictures.

2002 vacuum.gif Intake-PCV end.JPG Intake-plenum end.JPG Intake silicone seals2.JPG
 

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2001 Deville
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37 Posts
Discussion Starter #4
A good place to start would be to look at the wiring harness for frayed/exposed wires. I had to install a new connector to the MAF and splice the wires because some of them were exposed. I did it with a crimping tool but you can use heat.
I would also clean the connectors with electronic connector cleaning spray. If all parts checks okay, it might be an electrical problem.
Thanks for comment i was leaning towards that so i ordered a new connector examining the old one after i cut it i saw there was some play in the yellow wire
Im also looking into my alternator ground to body wire it is loose
 

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2001 Deville
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37 Posts
Discussion Starter #5
As posted, P 0101 points to MAF performance. Make sure there are NO air leaks into the intake ducting at or after the MAF.

Also, check the vacuum systems for leaks, when was the last time the TB and IAC were cleaned ? If the PCV dirty air line is broken/cracked that's a large vacuum leak directly into the intake manifold, passenger end tunnel.

Intake manifold bolt torque is only 7.5lb/ft - hope you did not crack a port bolt boss -

Here's your vacuum diagram - click to enlarge, use the < > to scroll - click the little grid bottom right to see the full pictures.

View attachment 574782 View attachment 574783 View attachment 574784 View attachment 574785
Thanks for the comment i just changed those manifold and rear valve cover gaskets along with a new pelleum and plugs i put a good tightening on those manifold screws with my regular ratchet what id didnt do was tighten down that throttle body enough so when i drove it to pick up my wife it started the high reving and jerking ,stumbling at stops so i managed to make in back home used throttle cleaner and found that vaccum leak around the throttle body then tighten them down sad to say the problem been every since then the p0101 and extemly high idle
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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67,158 Posts
I hope you used the correct torque setting for the composite intake manifold bolts. They WILL crack the manifold if too tight.

If there was a leak at the TB-to-water crossover joint then it's possible the new plenum is faulty. 3 long bolts, specific torque settings.

Did you correctly tighten the new plenum band clamp ?

You cannot guess at procedures and torque settings on these engines - do it by the book or you have all sorts of problems. ".... i put a good tightening on those manifold screws......" is VERY wrong.

Plenum 5.JPG Water crossover assembled.gif
 

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2001 Deville
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37 Posts
Discussion Starter #7
I hope you used the correct torque setting for the composite intake manifold bolts. They WILL crack the manifold if too tight.

If there was a leak at the TB-to-water crossover joint then it's possible the new plenum is faulty. 3 long bolts, specific torque settings.

Did you correctly tighten the new plenum band clamp ?

You cannot guess at procedures and torque settings on these engines - do it by the book or you have all sorts of problems. ".... i put a good tightening on those manifold screws......" is VERY wrong.

View attachment 574790 View attachment 574791
True i sprayed for vaccum leaks none found since i tightened the 3 bolts on tb
 

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2001 Deville
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37 Posts
Discussion Starter #8
I have replaced my pcm im thinking that is could be the culprit purchased from Ls1 after my original pcm crapped out have a lifetime warranty so if the new maf connector dont get it done then ill be sending the pcm in to be checked
 

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Registered
'93 SedanDeville 60 Special
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186 Posts
I would use a OBD-II scanner
Look to see that intake and coolant sensors are reporting correctly
Maybe one of their wiring connectors came off and once getting up to around 3,000 RPMS the PCM cannot adjust correctly
Look at the long term fuel trims and see if they are reporting too rich or lean
See if reporting excess misfires or engine knock
Look at MAF PIDs, a about idle MAF should be reporting around 2,700 Hz and maybe about 2 lbs/min air
ANY intake or exhaust leaks can full PCM and blame the MAF
Check to see if the front O2 sensors are showing balanced values left right (B1/B2) once engine goes into closed loop when coolant is at least about 140 degrees

The powertrain control module (PCM) uses that reading along with other sensor parameters to ensure proper fuel delivery at any given time for optimum power and fuel efficiency.

Basically this P0101 diagnostic trouble code (DTC) means that there is a problem with the Mass Air Flow (MAF) sensor or circuit.
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined expected range of the calculated MAF value.
Note: Some MAF sensors also incorporate an air temperature sensor, which is another value used by the PCM for optimal engine operation.

Ring out the MAF wires, there would be a ground, 1 wire is getting voltage, and 1 wire is the output of the MAF

If MAF is a 5 wire model then there is 2 wires for internal IAT sensor and if MAF only has 3 wires then there would be a external IAT sensor in air bridge.

Is it possible 1 sparkplug wire is not firmly connected
 

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2001 Deville
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37 Posts
Discussion Starter #10
Put on my new 5 wire maf connector no change today im unhooking tge positive and negative battery terminals to try a hard pcm reset i ordered the tech 2 should be here Wednesday spoke with the company i purchased my pcm from if all fails thurday i will be sending my pcm out
 

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'93 SedanDeville 60 Special
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186 Posts
Without the OBD-II scanner you may be throwing money and parts and not solve the problem

At the least verify the MAF wiring and its pins are not the problem
Use a multi meter and with the wiring connector off the MAF tuen the key on, engine off (KOEO)
Use the image I supply below and assure each circuit is functioning
You may need to hold probes onto test points while wiggle the wires to see if bad pins on wires

Look close and MAF has pin markings and by viewing the face of connector locations
Pins A and B are for the IAT sensor

575056
 

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2001 Deville
Joined
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37 Posts
Discussion Starter #12
Without the OBD-II scanner you may be throwing money and parts and not solve the problem

At the least verify the MAF wiring and its pins are not the problem
Use a multi meter and with the wiring connector off the MAF tuen the key on, engine off (KOEO)
Use the image I supply below and assure each circuit is functioning
You may need to hold probes onto test points while wiggle the wires to see if bad pins on wires

Look close and MAF has pin markings and by viewing the face of connector locations
Pins A and B are for the IAT sensor

View attachment 575056
Ok
 

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2001 Deville
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37 Posts
Discussion Starter #14
Here are some pics of what my little old code reader picked up
As for tge pins on the new maf connector everything check out ok
 

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'93 SedanDeville 60 Special
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186 Posts
Very hard to do diag with snapshot of screen with that type of scanner

Can it do recordings and then export the PID values to a .CSV file so I could analyze data in Excel
was weather about 50 deg
MAF in grms/sec says that is only about 1 pound/min yet the LTFT and STFT are reporting -10% too rich
and timing is odd at only -5 deg, thus if this was running in idle be more like 17 degrees

Is this engine, PCM and the tune totally stock

At only 1 lb/min airmass and fuel trims that rich, something is making the PCM think there is a lot more air so it is commanding the fuel injector ON time width higher then needs to be

Maybe best to private email me with a phone number to discuss as this way gains little info as to real problems
 

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'93 SedanDeville 60 Special
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186 Posts
Here are some pics of what my little old code reader picked up
As for tge pins on the new maf connector everything check out ok
If this was at idle, does that scanner show the MAF in Hz, if so it would be about 3,500 Hz
I would suspect unmetered air after the MAF so it cannot report what it cannot see thus check again
for ANY type of air leak, couplers, airbridge to TB, PCV or EVAP hose off, leaking

Check for leaks or bad vacuum hoses and your scanner reading should be when engine is in closed loop ( scanner show that PID ? (engine loop) if so is engine in closed loop and ECT showing 180-220 deg ?
Also see it reports MAP at 57 KPA, if that is at idle that is too high and being vacuum is inverse of that means low vacuum,
If at idle and IF your around sealevel I'd expect MAF at idle to be around 35-38 Kpa
You check that intake manifold it torqued down but again check all vaccum lines
 

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2001 Deville
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37 Posts
Discussion Starter #17
If this was at idle, does that scanner show the MAF in Hz, if so it would be about 3,500 Hz
I would suspect unmetered air after the MAF so it cannot report what it cannot see thus check again
for ANY type of air leak, couplers, airbridge to TB, PCV or EVAP hose off, leaking

Check for leaks or bad vacuum hoses and your scanner reading should be when engine is in closed loop ( scanner show that PID ? (engine loop) if so is engine in closed loop and ECT showing 180-220 deg ?
Ok here is my email [email protected]
 

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'93 SedanDeville 60 Special
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186 Posts
Jerry nice talking to you on phone
Go back as we discussed, find what the bolt pattern and toque down is for your intake manifold and while at it
recheck all vacuum hoses connected and not broken

Here is an example from a Corvette of bolting down order of the intake manifold bolts

575066
 

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2001 Deville
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37 Posts
Jerry nice talking to you on phone
Go back as we discussed, find what the bolt pattern and toque down is for your intake manifold and while at it
recheck all vacuum hoses connected and not broken

Here is an example from a Corvette of bolting down order of the intake manifold bolts

View attachment 575066
Thanks for the information also found the sequence and 89 ft lb specs on line plan to tackle the issue tomorrow
I will keep you posted

Thanks for the information also found the sequence and 89 ft lb specs on line plan to tackle the issue tomorrow
I will keep you posted
 

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