i just changed the lower intake manifold on my 98 grand prix v6 3.8 not supercharged, but im having acceleration problems, tonight ui was driving the car on the highway doing 90km/h started going up a hill, pedal to the floor and it was only driving at 80 km/h, and would not go any faster but once i get over the hill the accelerations slowely climbs up again, any ideas, please help, ive changed the spark plug wires also

just seems to holding back can someone help me please:th_nervous:, I also notice when the car is in park and i rev the engine up it seems fine! any answers please help, thanks

Welcome to the site!

Would it just not rev past 3k RPM? if so, I would suspect your catalytic converter is clogged and would need replacement.

Are their any SES lights being thrown?

Did you change plugs recently? what are they gapped at?

Where are you located in Ontario?

Sounds like a clogged cat to me.

yes im in ontario, it semms odd that it would be a clogged catalitic converter to screw up on mme right after the job was done, im gonna check my fuel injectors,vacuum lines, cause it could be because not enough gas is going to the engine, once i put it to the floor, the torgue of the engine is not receiving the gas it needs, i dont know!

doesnt really rev past 3k when im driving it, when its stopped in park it does!

the engine is under a much greater demand when its pulling the car then when its in park i say hook it up to a scanner and look at ur intake vaccuum thats the only way i found my clogged if the vaccuum is real low its telling you the engine is working to force the exhaust out. my cat was clogged but it still did its job of cleaning the exhaust so i never tripped a SES light

also how long ago did you change ur fuel filter?

yes, but where in Ontario are you located? Toronto? Ottawa?

After your other posts I really think it is a clogged cat like I mentioned in my first post.

Their is no load on the motor when it's in park so that doesn't matter.

If it were not getting gas then it would lean out and you would throw an SES light, probobly P0171.

im located in timmins up north, ya maybe it just gave out i dont know maybe the best thing is to bring it in but the funds are not there at the moment so im trying to figure this out before thats my option

I don't blame ya. But we have seen this a few times on this board alone.

Oh, I've never been to Timmins but my brother drives up there all the time delivering stuff for Bardon's (company).

You can get a hi-flow cat for fairly cheap. You can even get an aftermarket 3" downpipe for fairly cheap and that would come with the cat.

Try joining OQCGP.net and post a "looking for" thread there and see if anyone has one for sale.

yo i just noticed i have a faily large crack running along my muffler would that have anything to do with it you figure?

no, it would just make your car louder but would have no affect on this.

ok nevermind lol

ill take a looka that site though

No acceleration, although the engine and tranny are in good shape now. You had a leak that could introduce some nasty stuff into the exhaust system. Sounds like my 85 Firebird, and the verdict came back that the car had a bad catalytic convertor and bad tranny rebuild. You said nothing about the tranny, so I'm really leaning towards a cat.

Welcome to the site. Good bunch of folks here that are willing to share their info without flaming anyone. Be sure to post your fixes. Oh, and pics! We love pics here! Be sure to read our FAQ sections.