break up at 4500

[erics93talon]

i don't go on here much since i have learned to use the search function and usually find all my answers. but this new problem has me stumped. right now while driving the car wont go past 4500rpms. it bucks really bad and the wideband pegs lean. every now and then the car will make a pull to redline with NO breaking up and NO issues at all reading 11.0 on the wideband. i have done a boost leak test, SMALL leak at the throttle body/intake manifold gasket. changed plugs MULTIPLE times. tried a different coil pack, different wires, power transistor. don't know where to look now. since the wideband pegs lean when it bucks at 4500 i think its fuel related.

97 awd swapped spyder. non eprom ecu ECMLINK v3 full. FP hta86, topmount manifold, external waste gate, PTE 1000 injectors, jmf race manifold, q45 TB, full 3 inch exhaust, AFPR, 2g maf, big front mount, tial bov, 255 pump(rewired). FIC fuel rail. might be missing the other stuff, not sure. just to give an idea the setup.

 

[enriquez2000]

i don't go on here much since i have learned to use the search function and usually find all my answers. but this new problem has me stumped. right now while driving the car wont go past 4500rpms. it bucks really bad and the wideband pegs lean. every now and then the car will make a pull to redline with NO breaking up and NO issues at all reading 11.0 on the wideband. i have done a boost leak test, SMALL leak at the throttle body/intake manifold gasket. changed plugs MULTIPLE times. tried a different coil pack, different wires, power transistor. don't know where to look now. since the wideband pegs lean when it bucks at 4500 i think its fuel related.

97 awd swapped spyder. non eprom ecu ECMLINK v3 full. FP hta86, topmount manifold, external waste gate, PTE 1000 injectors, jmf race manifold, q45 TB, full 3 inch exhaust, AFPR, 2g maf, big front mount, tial bov, 255 pump(rewired). FIC fuel rail. might be missing the other stuff, not sure. just to give an idea the setup.

When mine did this a member on here told me to check my rocker arms. I was skeptical but pulled my valve cover and low n behold....

My only symptom was bucking around 4500.. normal driving was fine

 

[chrysler kid]

How is your fuel pressure on the rail?

Youre modified pretty heavily but I still wouldn't rule out a fouled plug, a bad wire, coil pack etc.

Check pressure on the fuel rail, if that is good check your plugs, plugs inspect normal then lay them out and inspect the wires.

Any codes or check engine lights yet?

 

[donniekak]

Post a log of the behavior.

 

[erics93talon]

When mine did this a member on here told me to check my rocker arms. I was skeptical but pulled my valve cover and low n behold....

My only symptom was bucking around 4500.. normal driving was fine

i've recently replaced the head and put cams in it. when i went through the head nothing looked out of the ordinary.
did your car do that all the time? or here and there. this problem comes and goes,mainly stays though.

 

[erics93talon]

How is your fuel pressure on the rail?

Youre modified pretty heavily but I still wouldn't rule out a fouled plug, a bad wire, coil pack etc.

Check pressure on the fuel rail, if that is good check your plugs, plugs inspect normal then lay them out and inspect the wires.

Any codes or check engine lights yet?

i have changed multiple plugs, two coil packs (one from a running and driving DSM.), i have changed wires as well.
pressure on the rail is fine BUT i have noticed when i turn the car off i do lose pressure. pressure drops slowly but fast enough you can watch it drop on the needle.

no codes, no check engine light. i have misfire checked hoping it would pick up a misfire.

my MAF honey comb has a small "dent" in it. appears to be a little pushed in, problem?

 

[erics93talon]

what should be logged when i do a log? i don't know what i would be looking for, ignition breakup?

also, i had my alternator tested and it came back as 13.64 NOT under a load AND 13.6 under a load, heat on high, lights and highbeams on, rear defrost on. i thought it was a voltage problem[/QUOTE]

 

[enriquez2000]

i've recently replaced the head and put cams in it. when i went through the head nothing looked out of the ordinary.
did your car do that all the time? or here and there. this problem comes and goes,mainly stays though.

Mine happened after i pulled cams to replace the cam seals.. i went through plugs and wires and opened the cover before i went on to coils on his advice.

Was worth the 15minutes to pull cover and check. And yes it was most the time but occasionally id get a good pull.

 

[erics93talon]

Mine happened after i pulled cams to replace the cam seals.. i went through plugs and wires and opened the cover before i went on to coils on his advice.

Was worth the 15minutes to pull cover and check. And yes it was most the time but occasionally id get a good pull.

i am open to everything so i guess ill take a peek in there tomorrow. i think the biggest clue is the wideband going lean then --- when it hits 4500 and bucks. lets me know its not getting fuel, correct?

 

[enriquez2000]

i am open to everything so i guess ill take a peek in there tomorrow. i think the biggest clue is the wideband going lean then --- when it hits 4500 and bucks. lets me know its not getting fuel, correct?

Yes and if its a rocker itll be your intake side if your going lean. May be totally different issue for you but its worth a look.

 

[donniekak]

You'll want to log rpm, maf(or Iat and map), tps, wideband, vehicle speed, coolant temp, knock, timing, etc, everything you would log when tuning the car.

 

[erics93talon]

You'll want to log rpm, maf(or Iat and map), tps, wideband, vehicle speed, coolant temp, knock, timing, etc, everything you would log when tuning the car.

okay, when the car hits 4500 and bucks should i let off the gas, or stay in it to see what its doing? ill try and log a few.

 

[donniekak]

I wouldn't stay in it if the car is bucking.

 

[enriquez2000]

my MAF honey comb has a small "dent" in it. appears to be a little pushed in, problem?

just noticed this... why are you running a maf and SD?

 

[erics93talon]

just noticed this... why are you running a maf and SD?

no SD just a MAF

 

[erics93talon]

i am not able to upload a log. i tried several times with a few different logs. keeps saying error.

 

[enriquez2000]

Try emailing the log to me. [email protected] and ill upload it for you if it comes through.

I had you confused with someone else when i mentioned SD.. too much multi tasking.

Did you check your rockers yet?