1990 740 GL w/ regina f-i. Intermittently stalls out

evolvo · Post by **evolvo** » 02 Jun 2008, 05:55

Hi Folks, I have a 1990 740 gl with the regina fuel inj system. The vehicle intermittently stalls out and starts very hard. Codes are 321, 221 121. I have replaced the sensor in the tube from the airbox, I replaced the MAF by the brake booster, cleaned the throttle housing, put in a new fuel filter, checked all the electrical connections-good. I traced each wire from the computer harness to each individual connection-all good. Checked ground-good. I am at my wits end. The car once started will run and idle perfectly. Then at a stop light it will almost completely cut out and then regain itself and run good for awhile and then the process starts all over again. I had it to my mechanic who ran the codes and put in the above items and traced all the wires and he is stumped. If there are ny suggestion oout there I would definately be appreciative. The only good thing about this is I get to drive my 1971 fully restored 142s around.
Help< I am losing hair over this and I do not have much to lose!!
1990 740 gl 135,000 miles

DeRail · Post by **DeRail** » 02 Jun 2008, 17:23

Code 2-2-1, correct me if I'm wrong is: Heated Oxygen Sensor

BillofDurham mentions code 121 can be caused by a fuel pump relay going sour, in another thread.

Maybe someone can chime in on 321.

You might try a new fuel pump relay or check inside and make sure everything is looking good -- there's a thread on repairing them.

evolvo · Post by **evolvo** » 05 Jun 2008, 04:55

Replaced The pressure regulator. put in a different fuel pump relay and she is still acting up. Hard to start and almost cutting out and then runs fine and the process cycles again.

. Would the oxygen sensor make the vehicle cut out? Any info is greatly appreciated. Thanks you for your help.

DeRail · Post by **DeRail** » 07 Jun 2008, 12:11

I would think that an O2 sensor may cause it to run strangely if it's not reporting the correct numbers to the injection system, but you might want to wait for someone else to chime in with a more definitive answer. Nothing's worse than swapping out all of these parts only for it to be unnecessary.

Cheers

briguy1960 · Post by **briguy1960** » 12 Jun 2008, 11:36

Re Regina FI

Do the codes mean the same thing as the Bosch FI. I also have a 740 with this system and there does not seem to be much info on them. What percentage of 740's came with this system. Why were they used at all?
I find my 740 is pretty hard to start in the morning. Once it does start it runs ok all though very sluggish up until about 15 mph.

Any links/info appreciated

B

Ron Richison · Post by **Ron Richison** » 05 Jul 2008, 09:46

to evolvo:
did you ever solve your problem? I had the exact same symptoms and was very frustrated. I did quite a few things and spent a bunch of money.
It ran better, then acted up again, now has developed another problem that may be related. I'm curious to know how your problem ended up???