Skipping a beat in full pull through second

[Zreberlcoe]

Whenever I start a full throttle pull from the low rpm in second gear to almost red line around 2500 rpm I feel a small jerk like a cylinder isn't firing and again sometimes somewhere between 3800 and 5000 rpm. I first thought it was the jerkiness of going over a bump while in high rpm but I noticed its consistency. Any ideas?

[603Racing]

Fuel starvation? Weak spark causing missfire under load?

[Zreberlcoe]

Fuel starvation? Weak spark causing missfire under load?

How could I test these two things?

[dnguyen1963]

1. Tee in a pressure gauge.

2. Watch this video

http://www.youtube.com/watch?v=q2DNJ8t7mzU

[Larzzz]

I think i have the same thing in my 86 325es. Mines in 1st 2nd and third gear, well actually all gears. it has a jerking feeling. Like not getting fuel or something. Mines between 2K and 4K rpm. Could it be a bad fuel filter?? i already relplaced spark plugs, air filter and some fuel hoses.

[Cabriolet]

your Kps is going bad

http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=12-14-1-720-852-M85&catalog_description=&Position%252FRPM%2520Sensor%252C%2520%2533%2532%2535i%252Fis%252FiC%252FiX%2520%2528from%2520%2530%2539%252F%2538%2537%2529%2520%2520%2520

[Larzzz]

What exactly is that?

your Kps is going bad
http://www.pelicanparts.com/cgi-bin/...2520%2520%2520

[LJ851]

What exactly is that?

Crank Postion Sensor and it's a good guess.

[FLG]

Think he meant cps and it very well could be.

See if ohms to spec, won't be definitive test though. I personally would replace it on these cars with an oem unit from the dealer, don't get aftermarket they're junk. After 20 years they are somewhat a time bomb

Sent from my SCH-I545 using Tapatalk 2

[Larzzz]

I work at a BMW dealership as a detailer/lot porter and get discounts in parts. Tomorrow ill go to parts and have them look it up! Thanks!

Think he meant cps and it very well could be.

See if ohms to spec, won't be definitive test though. I personally would replace it on these cars with an oem unit from the dealer, don't get aftermarket they're junk. After 20 years they are somewhat a time bomb

Sent from my SCH-I545 using Tapatalk 2

[Zreberlcoe]

Think he meant cps and it very well could be.

See if ohms to spec, won't be definitive test though. I personally would replace it on these cars with an oem unit from the dealer, don't get aftermarket they're junk. After 20 years they are somewhat a time bomb

Sent from my SCH-I545 using Tapatalk 2

The previous owner put in new spark plug wires. I'm thinking fuel filter is where I should start because who knows the last time that was changed.

[Cabriolet]

Think he meant cps and it very well could be.

See if ohms to spec, won't be definitive test though. I personally would replace it on these cars with an oem unit from the dealer, don't get aftermarket they're junk. After 20 years they are somewhat a time bomb

no, e30s dont have CPSs - this forum misuses it
CPS = Cam position sensor
KPS = Crank position sensor

[TobyB]

or your flapper door's not flapping correctly...

ohm out your AFM and see if there are irregularities in its resistance.

t