Rough Acceleration
03-30-2015, 10:59 PM
#1
Pro
Thread Starter
Rough Acceleration
Ok I am so close, I can taste it. Trying to get my car back on the road ofter the winter refresh.
Symptoms
Rough running when trying to accelerate and surging when holding at fixed pedal position. Car also does not run well at all when cold
So far.
Installed a rebuilt MAF last year during a top end refresh
Replaced my Injectors
I hooked up theo's diagnostic tool today. At first, my VBat was 11.6, and my TempII sensor was reading high at first, but after warmed up, got a good reading. (that was also replaced last year, and dropped in a new alternator this winter).
When the engine warmed up, these values got better, VBat 13.6 and temp was more realistic. The Vref was always at 4 volts.
The EZK is showing a fault code 34. My hall sensor may be bad, and can this cause my issues.
Someone also suggested to hook up a timing light to confirm a spark, and that looked good. Also no knock by theo's tool.
Also thinking that my grounds may need to be tended to, and just wondering if a vacuum leak somewhere can cause my symptoms. I think that is a likely candidate given the surging... Also worried about tempII sensor wiring
Finally the car is running rich all the time. I put in a new O2 sensor this winter.
So .... Low volts, fault code and surging with rough acceleration, and constant rich.
going to deox the ecu connections. If code 34 cont will replace hall sensor
Replace the main ground strap
thinking about popping off the intake and looking to see what is going on there.
Lots of Rabbit holes, and would love to get this sorted out.... I know I am close to getting the car tuned. I can use some help on sorting this out.
Symptoms
Rough running when trying to accelerate and surging when holding at fixed pedal position. Car also does not run well at all when cold
So far.
Installed a rebuilt MAF last year during a top end refresh
Replaced my Injectors
I hooked up theo's diagnostic tool today. At first, my VBat was 11.6, and my TempII sensor was reading high at first, but after warmed up, got a good reading. (that was also replaced last year, and dropped in a new alternator this winter).
When the engine warmed up, these values got better, VBat 13.6 and temp was more realistic. The Vref was always at 4 volts.
The EZK is showing a fault code 34. My hall sensor may be bad, and can this cause my issues.
Someone also suggested to hook up a timing light to confirm a spark, and that looked good. Also no knock by theo's tool.
Also thinking that my grounds may need to be tended to, and just wondering if a vacuum leak somewhere can cause my symptoms. I think that is a likely candidate given the surging... Also worried about tempII sensor wiring
Finally the car is running rich all the time. I put in a new O2 sensor this winter.
So .... Low volts, fault code and surging with rough acceleration, and constant rich.
going to deox the ecu connections. If code 34 cont will replace hall sensor
Replace the main ground strap
thinking about popping off the intake and looking to see what is going on there.
Lots of Rabbit holes, and would love to get this sorted out.... I know I am close to getting the car tuned. I can use some help on sorting this out.
03-31-2015, 04:34 PM
#4
Rennlist Member
A Hall sensor fault won't be the cause of the symptoms you describe. When you clean the grounds don't forget the two at the back if the engine, one is rather hidden by the throttle cable pulley wheel, but it is the main electronics ground point.
03-31-2015, 04:39 PM
#5
Pro
Thread Starter
Not a bad idea on the coli wires. I am not sure about the age of those. I replaced the ignition wires a couple of years back. Sounds like a weekend of deoxit and inspection is in my future.
04-03-2015, 12:12 AM
#6
Three Wheelin'
I'd have a look at the wire connectors for the Temp 2 and MAF sensors. Make sure there aren't stripped or cracked wires. Replacement boots are available as yours are likely hardened and glued by the factory to boot.
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10-09-2015, 11:18 PM
#8
Pro
Thread Starter
Well go the car going again today. Still have some crazy low temp badness, but once the engine warms, it does much better. I am beginning to think my tempII wires are crapped out. I have these tool which I can hook up and look at LH reedings, and I am rich. So getting a lot of unburt fuel to the O2 sensor I also get some crazy temp reedings that fluctuate from the TempII sensor.
I still have not quite figured this out yet, so I would be interested to see what you find. i also suspect an air leak in the system. I am going to do a cigar smoke test to see if I can find something.
The last thing I am discovering is that my fuel pressure does not hold in the fuel rail. So I am wondering if the system is getting air. I did replace the check valve on the fuel pump and when I did that, fuel came out, so I doubt that was it at all.
Some other folks have also suggested I may have a burt or stuck value. I need to find someone who will scope the engine for me. I also replaced my LH and ignition AMP with no improvement. My advice is to start simple and do the cheap stuff first. Look for an air leak as it is the most likely culprit.
Lots of stuff to chase down still.... And no real answers.... As someone else told me, it is usually 3-4 things happening all at once....
I still have not quite figured this out yet, so I would be interested to see what you find. i also suspect an air leak in the system. I am going to do a cigar smoke test to see if I can find something.
The last thing I am discovering is that my fuel pressure does not hold in the fuel rail. So I am wondering if the system is getting air. I did replace the check valve on the fuel pump and when I did that, fuel came out, so I doubt that was it at all.
Some other folks have also suggested I may have a burt or stuck value. I need to find someone who will scope the engine for me. I also replaced my LH and ignition AMP with no improvement. My advice is to start simple and do the cheap stuff first. Look for an air leak as it is the most likely culprit.
Lots of stuff to chase down still.... And no real answers.... As someone else told me, it is usually 3-4 things happening all at once....
10-10-2015, 12:06 AM
#9
Nordschleife Master
took the wife to the movies in mine tonight. about 20 miles of interstate at night and my car was loving it. after it warmed up of course. Even after being warmed up i still had some slight hesitation under partial load in the parking lot of the theatre. replaced all 4 ground cables today as well with some improvement to the electrical system but no magic fix. i guess the next step is replacing my ignition amp modules, then coils, then fuel pump? i'll keep you updated if you do the same. ha.
