1989 bmw 325i no Injector pulse

10

Asked by Oct 04, 2013 at 10:00 PM about the 1989 BMW 3 Series 325i

Question type: Maintenance & Repair

Car will run good all day on ether but will not start without .Obcc gives fault code 1252 - Fuel Injector #2 (single or group). Crank sensor was replaced, main relay seems ok, feul presure good, just no pulse going to the injectors. Any ideas ? I'm at a lose, mechanic couldn't figure it out either..

7 Answers

91,005

Recheck all of the ECM powers and grounds, remember that the injectors are triggered by a negative pulse, so one side is battery voltage and the other side is the trigger signal negative pulse, so usually if you loose the injector pulse then it is most likely the computer but make sure you have all of the necessary power and ground pathways, a service manual with wiring diagrams will really help with this.

10

all the grounds have been checked, they are good. Mechanic said he checked the computer it seems to be ok, only thing I can think is maybe the chip blew, I don't think he pulled the computer.

91,005

He needs to check for the injector pulse at the ECM, if it is there and not at the injectors then a wiring problem needs to be sorted out, if it is not at the ECM then the problem is in the ECM.

1 out of 1 people think this is helpful.
10

can you tell me the procedure for checking injector pulse at the ECM?

1 out of 1 people think this is helpful.
91,005

You need to find the injector driver wires coming out of the ECM, a wiring diagram should help with the color and location, once you locate the wires then using a low draw test light, led is preferable or a "noid light" this will prevent and injector driver damage due to high current draw, tap into the driver wire with one end of the light and put the other on a positive power source, crank the engine, the light should flash rapidly, if it doesn't then the usually the ECM needs replaced or rebuilt. If it does then you need to trace out the wiring until you find the broken circuits. Of course all of this is assuming that all of the power and ground pathways and sensors have been check and found to be good.

10

thanks for the info I'll besure to check

10

I found another ECM, confirmed good, and installed it .. still nothing. Any other ideas?

Your Answer

Add photo

Related Questions

  • bmw 320d 6 answers

    hi i have a bwm 3 series ..havent long bought it ...its started to lose power then when i reacted my location was off a cylinder black smoke from exhausted leaving black make on the ground ...when u...

    2002 BMW 3 Series 320d

    -

    Maintenance & Repair

  • BMW 2001 530i engine not recieving fuel 31 answers

    I know what the problem is but not what to replace or repair. My engine is not receiving any fuel so it won't run for more than 2-3 seconds. My father sprayed starting fluid in a spot that now slip...

    2001 BMW 5 Series 530i

    -

    Maintenance & Repair

  • DSC and Amber break lights 3 answers

    Driving along and the front right brake will pulse and then the two lights come on DSC and the amber brake light.took to BMW dealer could not find any thing wrong.Lights are gone after restart vehi...

    2001 BMW Z3 2.5i Convertible

    -

    Maintenance & Repair

  • NO INJECTOR PULSE. Please help !! 1 answer

    I bought a 89 Ford Bronco 2 2.9 knowing it didn't run. We got it cheap hoping it's just a small issue. The motor was recently rebuilt. It fires on starting fluid. It has 40psi of fuel pressure. ...

    Maintenance & Repair

  • fuel injector pulse signal 1 answer

    got a '91 tuned port.had sat for 7 years.replaced the fuel pump and filter,ign.module and ecm.cranks and dies.fuel pressure and spark are fine but injector pulse fades away.checked all ecm power and g...

    1991 Chevrolet Corvette Convertible

    -

    Maintenance & Repair

3 Series

Looking for a Used 3 Series in your area?

CarGurus has 33,573 nationwide 3 Series listings starting at $1,000.

ZIP:

Search BMW 3 Series Questions

BMW 3 Series Experts

#1 Tom Demyan
Tom Demyan
Reputation 4,550
#2 Robert Charlson
Robert Charlson
Reputation 1,530
#3 Matt Mankinen
Matt Mankinen
Reputation 1,180
View All

Related Models For Sale

Used BMW 5 Series
505 Great Deals out of 15,608 listings starting at $2,499
Used BMW M3
38 Great Deals out of 1,687 listings starting at $4,544
Used Ford Mustang
388 Great Deals out of 47,511 listings starting at $1,800
Used BMW 6 Series
74 Great Deals out of 3,267 listings starting at $6,995
Used Chevrolet Camaro
147 Great Deals out of 32,614 listings starting at $1,729
Used Honda Accord
769 Great Deals out of 88,118 listings starting at $1,150
Used BMW 7 Series
184 Great Deals out of 6,076 listings starting at $2,999

Used Cars For Sale

2017 BMW 3 Series For Sale
47 Great Deals out of 8,303 listings starting at $27,996
2016 BMW 3 Series For Sale
139 Great Deals out of 3,419 listings starting at $19,995
2015 BMW 3 Series For Sale
16 Great Deals out of 942 listings starting at $15,999
2014 BMW 3 Series For Sale
201 Great Deals out of 4,418 listings starting at $11,980
2013 BMW 3 Series For Sale
80 Great Deals out of 2,817 listings starting at $11,950