Author Topic: engine has flat spots (Read 4768 times)

xsjado · « **on:** September 19, 2007, 10:45:02 AM »

i dismantled my manifold to check my temp sensor.put it back and now the car idles roughly...during hard acceleration it bogs down during midrange...i dunno what happened.is it the dme?the sensors or a vaccum leak.please help.

christophbmw · « **Reply #1 on:** September 19, 2007, 07:15:12 PM »

check the basics first, check for a vacuum leak (check all hoses), check all sensors, see if anything got lodged in the intake system (like a rag), check fuel presure (is there a engine code?). post back with your results.

g0dspeed · « **Reply #2 on:** September 20, 2007, 03:58:30 AM »

Quote from: xsjado;33971

i dismantled my manifold to check my temp sensor.put it back and now the car idles roughly...during hard acceleration it bogs down during midrange...i dunno what happened.is it the dme?the sensors or a vaccum leak.please help.

bro.. have u tried to plug in the Modic to verify the fault?... i've experienced the flat spots... but i did check all the hoses...leakage...before using the Modic...it detected my knock sensors were faulty... prob solved after i changed them....

xsjado · « **Reply #3 on:** September 20, 2007, 09:23:48 AM »

hehe i've ordered the knock sensors...but then takes 3 weeks to arrive...maybe by then all my problems solved.thanx yall!!!

Vladi · « **Reply #4 on:** September 20, 2007, 03:42:59 PM »

How do knock sensors go bad, exactly? I mean, why? Just like that?

g0dspeed · « **Reply #5 on:** September 20, 2007, 10:52:36 PM »

Quote from: Vladi;34092

How do knock sensors go bad, exactly? I mean, why? Just like that?

frankly speaking... i really dun have the exact answer... i thought it was due to wear n tear.... after some time the sensors will become faulty.....others might have better answer...

xsjado · « **Reply #6 on:** September 22, 2007, 09:17:34 AM »

hmmm heat age wear and tear...old age maybe...mines off too...hooked up the engine to a laptop and it sez knock sensornerror...gets really frustrating when u floor it.....it retards ignitions...feel like it tho..it bogs down

christophbmw · « **Reply #7 on:** September 22, 2007, 03:38:30 PM »

Quote from: Vladi;34092

How do knock sensors go bad, exactly? I mean, why? Just like that?

volvo knock sensor fail ALL the time (and theirs are made by bosch too).

Vladi · « **Reply #8 on:** September 22, 2007, 03:43:53 PM »

Bogs every time at the same rpm or random? If let's say it bogs when you hit 2100rpm now, when you get to 2100rpm the next time will it bog again or not?

xsjado · « **Reply #9 on:** September 27, 2007, 11:16:55 AM »

bogs down during wot, at the same range...far beyon 2100 i feel.no tacho...

badboypolar · « **Reply #10 on:** September 27, 2007, 01:15:48 PM »

91 318's with the M42 engine don't have knock sensors.

If you took your intake manifold apart, then the problems arose, i'd get you have vacuum leaks.

xsjado · « **Reply #11 on:** September 28, 2007, 12:45:22 PM »

i have an e36 m42 engine in my e30...vaccum leaks are possible though

xsjado · « **Reply #12 on:** September 30, 2007, 11:24:49 AM »

bye bye flat spots....after a 7 hr battle with the manifold and array of sensors,not to mention bloody knuckes!!

g0dspeed · « **Reply #13 on:** October 10, 2007, 03:00:47 AM »

yuppp... u've nailed the culprits... godspeed xsjado...!