Thread: No acceleration?? Need help

So i've got a 98 200sx SE-R...I recently re-dropped the motor in and it worked fine when I took it out. For some reason now it doesn't get much acceleration...I cant put it past like 40 mph and it takes forever to get there. The car bogs out on me sometimes as well, and there's a bit of lag on it. I brought it to a local mechanic and they too are stumped, they said the timing is good, I just put a new cat in and the clutch is good as well. Their only suggestion was maybe it's because I don't have an o2 sensor in my aftermarket headers...could that be the reason?? Theres no bung on them, but if thats the case I have no problem getting one welded and put in...I also have the EGR blocked off but I wouldnt think that would be the issue. Any suggestions will be a big help...Thanks!!

No one I ask seems to have any idea, I hate to have to resort to it but I may have to bring it to Nissan to get it looked at by them.

Any engine codes? Check compression? All cylinders firing?

Does sound like timing if it's just running super slow but everything else is fine. Maybe the timing is retarded by a bunch for some reason, but your mechanic said it's fine. I hope he checked it right.

I wouldn't think the lack of a front O2 sensor or EGR would make it run as slow as you say it is.

Also, what stops you from going past 40mph? Is it RPM limited?

-G

I would put o2 sensor there if there was one before header swap and clear error codes and see what happens

Not sure about the engine codes, but I do know that all cylinders are firing...I'll have to check the compression when I get it back from the mechanic.

But yeah, I thought it was a timing issue when I first brought it to them, they looked at it, said the timing was way off, then they called me 2 days ago and said the timing was good so I'm not sure what the deal is with that.

And it just feels like it slowly gets to around 40 and yeah once i get there it'll pretty much redline and not go any faster, I don't wanna push it anymore than that.

Yeah, that's what i'm gonna try next, it definitely couldn't hurt, you never know.

What do you mean it redlines? What happens if you shift up a gear?

Read the forum post on how to check your timing yourself and do it. this is what I'm leaning towards especially given they told you they thought it was way off and then didn't.

Also, you can pull the codes yourself as well, there's a 'how-to' on that. Just involves turning a screw on the back of your ECU and counting the number of times your CEL blinks. It's easy. Barring that, I suppose you can take it to any of the auto parts stores and use their reader for free.

-G

Put in the o2 that does big help make sure your vacuum is tight too


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