94 3.4 falls on its face at about 70 mph

My buddies 94 seems to want to cut out/bog down at about 70mph...we checked all the plugs and wires and they are good (replaced all...problem still not solved)...could it be the fuel filter?
ANy other suggestions?

btw...also replaced fuel pump

clogged cat? :confused:

Does it just accelerate alot slower, or can you actually hear it sputtering or misfiring? If it just seems to get slower when you hit 3rd gear, thats just the lack of power. Most 3.4s have very little top end, mine is no exception.:p :o

Originally posted by 94GrayV6
94 PPM 3.4L A4 w/ 3.08 open rear

Unless you changed your gears, all 3.4s came with 3.23's. :)

Originally posted by V6 Punk 93
Unless you changed your gears, all 3.4s came with 3.23's. :)

no, all auto 3.4's came with 3.08's unless Y87 package....all manual 3.4 came with 3.23's if you don't believe me check the codes on your glove box.

GU2 = 2.73(only V8s)
GU4 = 3.08
GU5 = 3.23
GU6 = 3.42(came with Y87 option

actually blue it was 3.23s check your glove box.

Originally posted by zlightning
actually blue it was 3.23s check your glove box.

youre right I was thinking auto 3.8's

yes you were. Many peopel confuse the two. I wish gm would have confused the grand national turboed 3.8 for the 3.4.

I needed a new rear end about a 2 years ago, it is out of a 97.

Originally posted by zlightning
yes you were. Many peopel confuse the two. I wish gm would have confused the grand national turboed 3.8 for the 3.4.

yah would have forgot about the 3.4 and put a turbo on the 3.4...sigh

come to think about it I thought 94grayv6 said he had a 97 3.08 rear in his car awhile back.......or maybe I am just all wrong tonight...sigh

sorry to rob this thread GeneralZ but 94grayv6 is right the 3.4 has little power over 70(stock anyway)....might not be a clogged cat you would know that at other speeds.....can you tell a difference in the way the car sounds, rpms or what check fuel filter?

I just wanted to add my two cents on this one, Maybe its a freak incident for me but my 93 auto 3.4 stock seems to have plenty of power after 70mph, although sometimes it downshifts to far and then its bad but as long as it downshifts to 3rd gear and not 2nd, i have plenty of pickup till about 115 mph or so when it tops out.

My car is very strong in 3rd. @nd is the weak spot. 42-65 is slow.

Same situation here. Acceleration is pretty good up till about 70mph and then its like you're driving through water instead of air.

yeah if you leave it in OD its even worse

hmmm guess its just me then, well, I just messed my v6 up pretty bad so I got a hook up with someone on the message board for an 95 LT1 engine with 80,000 miles on it, So I'm gonna rebuild that and throw it in there. Hence, no acceleration issue anymore! No hard feelings though guys....I'll let you know how it goes.