I did a head and cam swap, had a tune done, and put on a slightly used opti.. the car surges or stumbles kinda, when cruising can notice it from around 1,000 to 2500 rpm's. just feels like a strong head wind, just surging.. it dosen't throw any codes... can it be the opti? what do the opti's do when they go out? any help..

 

ttt..anyone

 

what you describe sounds like a tuning issue. Didn't we do the tune on that car? If so send it back especially if you can get a datalog so we can clean it up a bit for you.

 

pm sent..

 

Check for vacuum leaks as well.

Could be opti too.

Datalog would really help.

 

I ran a datalog..

map was reading 2.8 volts at idle or 62 or .62 can't remember. and 1.8 v. at 2700 rpm's
blm's 160 on both sides at idle very lean, 144 both sides at 2700rpm's.
left integrator 185 at idle right one is 160 at idle. 116-138 both sides going down highway.
barometer was reading 4.8 at idle. it feels really like cam surge to me not really a miss. or it feels like stumbling.. I did notice my fuel pressure was dropping when going wot in the higher rpm's it would drop from 43 down to 38 then I would let off. I am replacing fuel filter today. the fuel pump is a walbro 255, plus accel afpr.. and I have a elect.fuel press. guage. hopefully the filter is one problem.
the injectors were reading 4.5 at idle, no injector faults.. no codes except qdm 2 fault??

 

Alvin could be right. I had a tune from him during the winter that worked great but the summer heat started owning me so I pulled like 9 or 10 degrees from 3000+ and about 6 degrees below. Now the car drives like crap as you described.