940 turbo sluggish take off and stalling when turbo engages

steve smith · Post by **steve smith** » 19 Oct 2009, 07:03

Hello I am new to the world of volvo's.I have recently purchased a 1993 940 turbo sedan love the car but having problems and need answers please.When in normal driving speeds 35 to 60 it seems ok till you try to accelerate to obtain higher speed and then it starts bucking misfiring and sounds awful when it engages the turbo(when idiot gauge on dash goes from black to grey for turbo) also when the car is sitting at stop light it is fine idiling but when you try to press the gas to move from light it dies or you feather gas it will eventually move on out.Now I have learned from this site how to read the codes on the computer it is throwing a 151 code on the one marked A on the number three portand a 122 code out the one marked b ont he number two port can someone please tell me what these codes are tanks in advance to any response i get

Post by **billofdurham** » 19 Oct 2009, 12:08

Welcome to Matthew's Volvo Site.

I have deleted your later post as it was asking the same question.

Diagnostic box B isn't used for engine or transmission fault finding. However, B2 is used for the cruise control. 1-2-2 indicates that the speed was below minimum/no signal and is set as soon as the ignition is switched on. It will remain stored until the vehicle speed exceeds 22mph for at least 15 seconds. The test for B2, therefore, is different from other tests as it must be done after a drive where the speed exceeded 22mph for at least 15 seconds and the engine must not be turned off until the diagnostic test is completed. If 1-2-2 is still showing after the road test, before switching off the engine, the unit isn't receiving a signal.

Diagnostic A3 is ABS. 1-5-1 is an open circuit or shorted to supply on the left front wheel sensor. The ABS light should be on.

Engine diagnostics are carried out on box A port 2 for the fuel system and port 6 for the ignition. What codes, if any, did you get on these?

Bill.

steve smith · Post by **steve smith** » 21 Oct 2009, 06:18

Thank you Bill for your first response. I went out and checked port 2 on side A and is throwing two codes the first code it gave me is 121 and then I pushed the button again like I was supposed to and it gave me a 113 code. Port 6 did not give me any code except 111 which I believe means it is normal correct?Thank you in advance for any response I recieve

Post by **billofdurham** » 21 Oct 2009, 12:36

1-2-1 is a fault in the Mass Air Flow (MAF) meter which is mounted on the fresh air intake near the air filter. Often the MAF becomes dirty and can be restored by spraying it with a proprietary cleaner available from car parts stores. If that doesn't solve the problem the MAF needs to be tested.

To test the MAF
1) Remove rubber sleeve from airflow meter to uncover wire
connector. DO NOT disconnect connector. Using a voltmeter, backprobe
connector terminals. Connect voltmeter leads between ground and
terminal No. 5 on mass airflow connector. Voltage reading should be 12 volts.
2) Connect voltmeter leads between terminals No. 1 and 5 on mass airflow connector. Voltage reading should be 12 volts.

1-1-3 is a short term fuel problem which has probably been triggered by the MAF code. The Electronic Control Unit (ECU) takes information from many sources to determine the amount of fuel to put into the engine. If the MAF is sending spurious info the ECU will put in the wrong amount of fuel.

Try cleaning the MAF, erase the codes and see how it goes.

1-1-1 is no fault codes stored.

Bill.

steve smith · Post by **steve smith** » 21 Oct 2009, 23:43

Thanks Bill for your help I cleaned the maf with maf cleaner reset the codes and now she runs like brand new and there are no codes stored or popping back up so far

Post by **billofdurham** » 22 Oct 2009, 12:01

Let's hope it continues. Thank you for the update.

Bill.