Car is doing the Stutter Step?!

[zerokid5555]

Need help with stutter step! Car is a 1989 325i 5 speed...car's engine totally loses's power for a second than cuts back on while driving! Lights and tach still work when this occurs. Only the engine completly loses power for a second and than it will jerk rite back on. It mainly happens when i get on the car /go heavy on the gas..sometimes jerking the car a few times(on, off, on off). The car drives fine when light on the gas shifting at a lower rpm. Anyone know what might be causing this?

[xwill112x]

maybe a maf?

[Bimmerista]

TPS sensor perhaps

[jlevie]

Does the tach drop when the engine cuts out more than would be appropriate for the slight loss of road speed? If so the CPS, main relay, or fusible link are the prime suspects. If the tach remains constant but the econometer drives towards zero the fuel system or fuel pump relay become the prime suspects. A bad spot in the AFM's resistance trace can also cause this, in which case the tach and econometer are usually unaffected except that the econometer may drive towards 40.

[zerokid5555]

Does the tach drop when the engine cuts out more than would be appropriate for the slight loss of road speed? If so the CPS, main relay, or fusible link are the prime suspects. If the tach remains constant but the econometer drives towards zero the fuel system or fuel pump relay become the prime suspects. A bad spot in the AFM's resistance trace can also cause this, in which case the tach and econometer are usually unaffected except that the econometer may drive towards 40.

Appreciate the feedbacks. Just took her for a fast spin around the block...At first she didn't want to start stutter stepping i eventually got her to sutter. The results of my laps were the tach does seems appropriate for the slight loss of road speed. The econometer does infact drive towards 40 when stuttering.

[jlevie]

Then I'd look to the AFM and TPS.

[zerokid5555]

does my 89 have a fuel pump relay?

[zerokid5555]

Never mind 98% sure its fixed! Went outchecked the fuel pump relay and it was extremely loose. Put her back in solid and took her for a test run...No Stutter Step! Thanks again for all your help!

[Hey_You]

Good to hear! Mine did the same thing (although a m10) so I just went ahead and replaced the whole fueling system almost. Cleaned the contacts on my Fuel Pump Relay and regapped my plugs, no more stutter stepping for me either!

[zerokid5555]

^ Nice! I have that kevlar emblem in ur avitar on my car :pimp:

No Stutter Stepping and it feeels so good!

[Alpine30 Wolf]

i'll have to check mine too after reading this because ive had this problem for a while now.