G 50 problem, what is it

[ejXa q45]

G 50 problem, what is it i need some idea 's what this could be i posted something before but this is the hole story from day one my q had a vibration first it started at 40 mph and 50 mph with a violent bucking and jerking and also it shake in any gear while driving or parked this happened after the violent bucking. so i fix and cleaned MAF, throttle body and ACC no luck. i started to loose power when i could not find what the problem so took the car to a mechanic and he replaced coils and plugs still this did not fix the problem ...... he show me coil pack and said it was burned up there was some burn marks on them so i got new ones he said i got new spark plugs but did not see them so don't know if they are done .this was about 8 months or so the car started to loose power up hills and making turns. all together the car had less throttle response so adjusted the ACC and throttle cable still no luck then one day the cars idle started to jump when driving its kinda like it was adjusting it self but continue all the time, only when driving. this happened for one day or so until it got so bad it would not go over 2000 rpms with out flooring it and then still it would not move like it should .then one day i blow passenger side exhaust going up hill with it floored drove home and fix it the next day the car had this problem where the car would drive fine until wormed up then would not go over 2000 rpm at all. feels like timing is wrong when it worm up so i got a timing light and timed it but that was not it the car backed fired when worm and if i start it and turn off will not start back up

if the cars in park and rev up its it is fine and will go over 2000 rpms but in drive it feels like power is not going to weels and will not event go up car ramps os i can get under it

correct me if i am wrong when its cold it in a pre-programed mode for timing, fuel, and spark. until it is worm up.... when wormed up is when this problem happens . would it be possibly to trick the ecu to make it think its in this safe mode all the time. what happened when ks go bad is it smilier to what happened to my Q or what about injector 0-rings or FPCM to much gas would make it back fire maybe mes with idle and acc try to compensate for raise in idle make it jump

i need some idea 's what this could be any input on problem that would cause any of these symptoms similar problem are also welcome

[maxnix]

Adjusted cables? Not a good sign as they require free play.

IAC has the standard 2.5-3.0 turns out from closed.

Have you measured your fuel pressure? Maybe a little recent maintenance history is in order.

[goody90q45]

Have you measured your fuel pressure? Maybe a little recent maintenance history is in order.

I agree. Sounds like fuel pump/FPCU issues. Check your fuel pressure.

[ejXa q45]

never replaced any fuel parts but the fuel filter new CAS fuel filter cleaned sensors and connectors cleaned throttle body cleaned ACC new thermostat synthetic oil on time new transmission drive shaft balanced coils and plugs

what i removed A/C from belt air box for a intake removed catalytic converter

i think it might be fuel pump and or controller as well, is there a way to test them but it also she back fires like too much fuel

[elwesso]

dont take this the wrong way, but dont think that you can trick the ECU into thinking its always cold... Thats a very band-aid fix and its not acceptable!!

Check fuel pressure immediately.. Maybe try grounding the fuel pump (to force high speed) and see if that makes it run better.. otheriwse id look into something MAF related....

[ejXa q45]

dont take this the wrong way, but dont think that you can trick the ECU into thinking its always cold... Thats a very band-aid fix and its not acceptable!!

Check fuel pressure immediately.. Maybe try grounding the fuel pump (to force high speed) and see if that makes it run better.. otheriwse id look into something MAF related....

i don't take any thing the wrong way for i do not have much mechanical knowledge. i got a ohms tester and will ohms injectors maf and ks but, how can i test fuel pump for pressure and see if the FPCM is working

[elwesso]

you cant test the FPCU or MAF for ohm and expect anything.... Thats not the way you check those sensros....

Go to autozone and get a fuel pressure gauge with a T fitting.... it needs to be capable of reading 50psi....

[ejXa q45]

well it a voltage meter ..or something like that

you cant test the FPCU or MAF for ohm and expect anything.... That's not the way you check those sensors....

Go to autozone and get a fuel pressure gauge with a T fitting.... it needs to be capable of reading 50psi....

how do i test these sensors, i guess idk then how can i do it i test the fuel pressure by removing the line for filter and reconnect t fittin right

thanks

[elwesso]

The only really accepted way to test these units is to replace them wtih known good... Fortunately, you should have both of those as a spare even if yours are known good.... and they can be had used...