Wacky voltage, lots of studder

[norice4me]

Well this is my first post, to bad its in the problems section. Before the flames start, i did do a lot of searching on this subject. Anyways, i just bought a used 90 eclipse gsx. The car had some work done to it, ported 16g, evo manifold, afc, tt, ebc, buschur intercooler and exhaust, 255 fuel pump and 550 injectors. The car hualed ass for a couple of days but all of the sudden it started to studder at around 4000-4500 rpm at WOT. It wasnt violent like fuel cut would be, just a studder and then pulls through it. I checked the voltage on the TT and it was around 13.6, but then it started to dip to 13.0 and 12.6 at some instances both at idle and cruising with accesories on and off. With that i changed the alt out for a new one and now it is even worse. It still studders in the higher rpm range and sometimes lower but now it drops to around 11.4 volts which is showing the alt is doing absolutly nothing now. Im guessing i have a bad ground somewhere but other than that im pretty stumped

 

[Defiant]

How old's the battery? Is it bolted down?

 

[norice4me]

its a new battery and is bolted down tightly. I found out that the alt belt was loose so i tightened it and that brought the voltage back up to around 13.6v at idle. It still misses from around 3700rpm and up. i change the plugs and gapped them to .28 and still the same thing. The wires are magnecore and are brand new. I noticed at idle or slowing down to idle the engine will pulsate a couple hundred rpm and them settle down to normal. Also i just found out that the coil is original with 135000 miles on it, im guessing that could also be my problem

 

[TalonTSi-AWD91]

Have you checked your ECU caps?

 

[norice4me]

Well. i fixed the studdering problem..... (Something minor) it was a loose injector plug, so that is gone I replaced the alternator and I still have really low voltage though. 13.1 at idle with high beams on, dips to 12.6 when fan turns on but goes back to 13.1. If i put the brake lights on it will also put the voltage back down into the mid 12's. The ECU is just recently reprogrammed after it failed for the previous owner. So thats is fairly new (year old). I just checked and saw that the walbro 255 pump was never rewired. Could that have that much of a draw? Car runs great but the voltage dropping is a little scary.

 

[Sotarts]

My buddy's 97 TSi, never goes more than 13.x @ 80+ mph. I don't see a problem.

 

[norice4me]

well i just talk to the old owner and he said it was normal so i am not thinking about it anymore thanx guys for the help.

 

[ltvarney]

Yeah the voltage thing is normal man. With a 90 amp alternator and an Optima Redtop my car idles at 12.3-13 with both fans whirring and the highbeams on. You can look into better grounds if you want to try and raise it.

 

[Sotarts]

Speaking of voltage.... does anyone know where I can get a Canadian-spec alternator? Not used either. Brand new/OEM manufactured.

As far as I remember, Canada DSMs have a higher amp alternator. Am I right?

 

[TalonTSi-AWD91]

Originally posted by aovsi
Speaking of voltage.... does anyone know where I can get a Canadian-spec alternator? Not used either. Brand new/OEM manufactured.

As far as I remember, Canada DSMs have a higher amp alternator. Am I right?

Yep, you can get some info about it here.

 

[norice4me]

thank you guys for the help now i dont have to worrie about it now. ill just worrie about the little things now.

 

[pickens]

is your studder problem still fixed or did it come back. I'm experincing the exact same thing.

 

[norice4me]

it is still fixed y dont you try cheaking you injector plugs one of mine was loose

 

[kev98gsx]

how do u check ur injector plus and on a 2g gsx where are they located???