91 740 non-turbo....just pulled codes
#1
07-08-2010, 07:02 PM
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91 740 non-turbo....just pulled codes
got the following codes:
Fuel System Diagnostics-
2-3-2 (Lambda Adjustment - Check Intake Manifold & Fuel Pressure) Fuel Pressure Regulator or Fuel Relay ???
1-2-2 (Air Temp Sensor Signal - Check Sensor) MAS Air Flow Meter or EGR Temp Sensor or Air Charge Sensor or some other sensor???
i believe EGR and Air Charge are the same...one located in the EGR valve or the other one in the EGR Pipe???
2-3-3 (Idle Valve - check intake manifold & check idle valve) Idle Air Control Valve??? (and where is it located??)
Ignition System Diagnostics-
1-4-3 (Knock sensor signal) Knock Sensor??? and location???
your thoughts???
Fuel System Diagnostics-
2-3-2 (Lambda Adjustment - Check Intake Manifold & Fuel Pressure) Fuel Pressure Regulator or Fuel Relay ???
1-2-2 (Air Temp Sensor Signal - Check Sensor) MAS Air Flow Meter or EGR Temp Sensor or Air Charge Sensor or some other sensor???
i believe EGR and Air Charge are the same...one located in the EGR valve or the other one in the EGR Pipe???
2-3-3 (Idle Valve - check intake manifold & check idle valve) Idle Air Control Valve??? (and where is it located??)
Ignition System Diagnostics-
1-4-3 (Knock sensor signal) Knock Sensor??? and location???
your thoughts???
#2
07-09-2010, 02:37 AM
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2-3-2 is a O2 sensor code, when you have both a MAF code and and o2 sensor code usually your ECU is bad...easiest way to diagnose is if you had an extra ECU that you knew was good and plugged it in, drove for a while and then rechecked codes...if they come back then you know you have a bad ECU...if you don't have another ECU then you can test the O2 sensor and MAF with a multimeter preferably a Fluke 88 and see if they are indeed bad or not...but without know how or proper tools your shooting in the dark...but I can tell you from my many years of experience if you have that many codes there is a REALLY GOOD chance your ECU is bad...also, is your check engine light on?
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07-09-2010, 07:45 AM
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#4
07-09-2010, 11:27 AM
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#5
07-12-2010, 05:45 AM
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Sorry for the double-posting...here is a copy from my 1st post, describing what is going on.....
so i can track everything in just one post..
If the ECU is bad, would the car run at all??
[From 1st post]
91 740, non-turbo...
think i may have a couple issues here...
recently, the car has been getting harder to start...have pretty much determined that i have to crank it for 2-3 seconds, shut off, and repeat this process 3 or 4 times and it finally starts...
secondly, after getting it started, if i step on the gas, the car wants to die, unless i quickly feather the pedal and build the rpms up....once the rpms get up, car drives fine..until you stop, then have to feather the pedal again...
few things i have done:
replaced Mass air meter (or whatever they call it on volvos)
removed air intake hose to throttle body, also removed throttle body and gave it a good cleaning. gave valve cover/oil breather cap a good cleaning. put new spark plugs and wires in it back in november.
after doing all this, the car is still having the above mentioned starting issues but runs great after it starts, no hesitation when steeping on the pedal...ran great like that all day yesterday, with multiple starts/stops...started hesitating again last night...
few things i have been thinking of:
FPR (looks new)
fuel pump relay (the white one behind the ashtray??)
one of the fuel pumps (has 2 right? probably the one in the tank)
fuel pump check valve??
fuel filter??
also to note, i am not getting a check engine light on the dash.
your thoughts or suggestions?
[End of first post]
bad ECU??
if the ECU is gone, then the engine wouldn't run at all would it??
so i can track everything in just one post..
If the ECU is bad, would the car run at all??
[From 1st post]
91 740, non-turbo...
think i may have a couple issues here...
recently, the car has been getting harder to start...have pretty much determined that i have to crank it for 2-3 seconds, shut off, and repeat this process 3 or 4 times and it finally starts...
secondly, after getting it started, if i step on the gas, the car wants to die, unless i quickly feather the pedal and build the rpms up....once the rpms get up, car drives fine..until you stop, then have to feather the pedal again...
few things i have done:
replaced Mass air meter (or whatever they call it on volvos)
removed air intake hose to throttle body, also removed throttle body and gave it a good cleaning. gave valve cover/oil breather cap a good cleaning. put new spark plugs and wires in it back in november.
after doing all this, the car is still having the above mentioned starting issues but runs great after it starts, no hesitation when steeping on the pedal...ran great like that all day yesterday, with multiple starts/stops...started hesitating again last night...
few things i have been thinking of:
FPR (looks new)
fuel pump relay (the white one behind the ashtray??)
one of the fuel pumps (has 2 right? probably the one in the tank)
fuel pump check valve??
fuel filter??
also to note, i am not getting a check engine light on the dash.
your thoughts or suggestions?
[End of first post]
bad ECU??
if the ECU is gone, then the engine wouldn't run at all would it??
Last edited by mrdjflores; 07-12-2010 at 05:49 AM.
#6
07-12-2010, 01:39 PM
Banned
Sorry for the double-posting...here is a copy from my 1st post, describing what is going on.....
so i can track everything in just one post..
If the ECU is bad, would the car run at all??
Yes just poorly....and giving incorrect codes...
[From 1st post]
91 740, non-turbo...
think i may have a couple issues here...
recently, the car has been getting harder to start...have pretty much determined that i have to crank it for 2-3 seconds, shut off, and repeat this process 3 or 4 times and it finally starts...
secondly, after getting it started, if i step on the gas, the car wants to die, unless i quickly feather the pedal and build the rpms up....once the rpms get up, car drives fine..until you stop, then have to feather the pedal again...
few things i have done:
replaced Mass air meter (or whatever they call it on volvos)
removed air intake hose to throttle body, also removed throttle body and gave it a good cleaning. gave valve cover/oil breather cap a good cleaning. put new spark plugs and wires in it back in november.
after doing all this, the car is still having the above mentioned starting issues but runs great after it starts, no hesitation when steeping on the pedal...ran great like that all day yesterday, with multiple starts/stops...started hesitating again last night...
few things i have been thinking of:
FPR (looks new)
fuel pump relay (the white one behind the ashtray??)
one of the fuel pumps (has 2 right? probably the one in the tank)
fuel pump check valve??
fuel filter??
also to note, i am not getting a check engine light on the dash.
You won't with a bad ECU...
your thoughts or suggestions?
[End of first post]
bad ECU??
if the ECU is gone, then the engine wouldn't run at all would it??
so i can track everything in just one post..
If the ECU is bad, would the car run at all??
Yes just poorly....and giving incorrect codes...
[From 1st post]
91 740, non-turbo...
think i may have a couple issues here...
recently, the car has been getting harder to start...have pretty much determined that i have to crank it for 2-3 seconds, shut off, and repeat this process 3 or 4 times and it finally starts...
secondly, after getting it started, if i step on the gas, the car wants to die, unless i quickly feather the pedal and build the rpms up....once the rpms get up, car drives fine..until you stop, then have to feather the pedal again...
few things i have done:
replaced Mass air meter (or whatever they call it on volvos)
removed air intake hose to throttle body, also removed throttle body and gave it a good cleaning. gave valve cover/oil breather cap a good cleaning. put new spark plugs and wires in it back in november.
after doing all this, the car is still having the above mentioned starting issues but runs great after it starts, no hesitation when steeping on the pedal...ran great like that all day yesterday, with multiple starts/stops...started hesitating again last night...
few things i have been thinking of:
FPR (looks new)
fuel pump relay (the white one behind the ashtray??)
one of the fuel pumps (has 2 right? probably the one in the tank)
fuel pump check valve??
fuel filter??
also to note, i am not getting a check engine light on the dash.
You won't with a bad ECU...
your thoughts or suggestions?
[End of first post]
bad ECU??
if the ECU is gone, then the engine wouldn't run at all would it??
#7
07-12-2010, 07:58 PM
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#8
07-13-2010, 02:03 AM
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which number do you have and what is the color of the label? Is it a 951 or 933??There are some that interchange and some that are used both in the 240's/740's and 940's...
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07-13-2010, 07:04 AM
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#10
07-13-2010, 05:13 PM
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#11
07-14-2010, 08:52 PM
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#12
07-15-2010, 02:25 AM
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think your looking at the wrong box...the ECU you need is most likely one of these a Bosch 556,933 if your car has EGR or 951 it is a metal box with a label on it. Lable will be pink, white, etc..it will say BOSCH or if replaced may say PROGRAMMA...last three numbers will be one of the above...all of these should work on your car but only 933 will work if you have EGR...look on Ebay there are tons... type in search Volvo ECU 933/951/556
Last edited by volvoguy2323; 07-15-2010 at 02:28 AM.
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07-15-2010, 05:49 AM
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07-15-2010, 07:29 AM
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#16
07-15-2010, 12:59 PM
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07-15-2010, 05:08 PM
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think your looking at the wrong box...the ECU you need is most likely one of these a Bosch 556,933 if your car has EGR or 951 it is a metal box with a label on it. Lable will be pink, white, etc..it will say BOSCH or if replaced may say PROGRAMMA...last three numbers will be one of the above...all of these should work on your car but only 933 will work if you have EGR...look on Ebay there are tons... type in search Volvo ECU 933/951/556
not behind the ashtray...not under the passenger side dash...can't see anything similar underneath the hood...
confused
how many different ECU's are in this car??
#18
07-15-2010, 06:28 PM
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07-15-2010, 07:04 PM
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so is the general consensus still a bad ECU...or all those other sensors???
again, no check engine light....have already replaced the "unit" between the airfilter box and the throttle body...Mass Air Flow Meter, Air Temp Meter, or whatever it's called.
also, what/how do you determine what fuel system this car has....been told it's Regina...also have been told it's not....
or just douse the car in gas and have a big bonfire
again, no check engine light....have already replaced the "unit" between the airfilter box and the throttle body...Mass Air Flow Meter, Air Temp Meter, or whatever it's called.
also, what/how do you determine what fuel system this car has....been told it's Regina...also have been told it's not....
or just douse the car in gas and have a big bonfire
#20
07-15-2010, 07:47 PM
LH systems are made by Bosch,Regina fuel systems are made by Bendix.
Just by looking at your under hood pic it's easy to spot.First thing is the coil and power stage are one unit,next it uses a map sensor not a maf sensor.
(The "unit" between the air filter box and the throttle body that you were referring to is the Intake air temp sensor.)
I've worked on a few of these systems and they are a P.I.T.A.
Have you cleared the codes?
If you have,are the same codes coming back?
Pour at least two gallons of gas on the car,light and enjoy.
Dan
Just by looking at your under hood pic it's easy to spot.First thing is the coil and power stage are one unit,next it uses a map sensor not a maf sensor.
(The "unit" between the air filter box and the throttle body that you were referring to is the Intake air temp sensor.)
I've worked on a few of these systems and they are a P.I.T.A.
Have you cleared the codes?
If you have,are the same codes coming back?
Pour at least two gallons of gas on the car,light and enjoy.
Dan
Last edited by TURBO 245; 07-15-2010 at 08:20 PM. Reason: info change