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surging on acceleration


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Hi guys and gals, my 97 Pathy has a slight surge in power when cold and around 30/40mph range. I don't notice any power loss just the up and down with light throttle and the surge is not something that shows on the tach. Fuel filter changed, thinking maybe plug wires? It has 130k on it. Not a big deal but something to tinker with in the slow winter time.

 

Thanks

James

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Hey thanks, I did not even think of that. I sprayed it down and waiting to dry. I will test drive it in a bit and follow up. Will be worth the $7 for the MAF cleaner if it works but at the least it can't hurt.

 

James

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check the intake hose between the filter box and intake manifold for cracks, leaks, loose clamps etc. Make sure all the vacuum lines running off it are good too. surging is a symptom of an intake leak after the maf.

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Hmm...I just started experiencing the same thing but at higher RPMS.

 

I drive over a mountain pass daily and on the approach/incline, if I have the pedal down all the way, it will sometimes start surging. I actually have to let off the gas slightly and then it's like something kicks in and it starts accelerating. :scratchhead:

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Well the cleaner did not make much if any difference, the fuel filter is new so I will now check vac lines as they are old and are probably cracked.

 

James

 

I was having a similar problem and changing the gas filter had the biggest impact. I also cleaned the MAF and I felt the difference as well.

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new oem or off brand fuel filter?? I bought a replacement filter from canadian tire and it was garbage, after installing it I could no longer go full throttle. Tested alot of things, eventually fuel pressure, and I only had something like 25psi at the fuel rail, I bypassed the fuel filter and sure enough it went back up to 45 I believe.

 

OEM was ALOT more expensive I remember, and I dont recall what brand they sold me at crappy tire, but fuel pressure could be something to check if you have a tester

 

Air leak upstream of the MAF would cause this to, but it wouldnt only really be at a certain speed range like you say it only happens at

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I saw on one response to spray the sensor when it is hot. Is this correct and how do you know when it is hot. Mayne after driving home from work. I only sprayed mine after sitting parked for the evening in the garage.

 

Thanks

James

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Some people have reported problems after using the MAF cleaners. Pay $3 for a bottle or isopropyl alcohol, grab a screw drivers (phillips IIRC) and some Q tips and clean it 'manually'. I've done this on WD21s and an R50 and the procedure is identical other than the unit placement and shape, the R50 is easier to access IIRC.

 

B

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I tried to clean a MAF with brake cleaner and it went from being broken to being broken. I had no choice but to replace mine. Luckily, I got a used one for $7 and it raised my mileage (and power I must say) by about 50%.

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Ok so I have checked all vac lines and they look good, I have used the alchole on the sensor to clean it a couple times. It seems to be getting slightly worse after cleaning so I am pretty sure it is the sensor. The question is when I feel the light surging the rpms are not changing? I am trying to not just start buying parts and have it be something else. I have not thrown any codes that my reader will show anyway.

 

James

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Well the new sensor did not fix the problem. I guess I will wait till I get a CEL code one day. The issue is not that big of a deal to keep sinking money into things that might not fix the problem.

 

James

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So I'd like to know if you think this is a tranny issue or a engine issue.

 

I have the VQ3.5, but I think I have the same symptoms.

Flares 3-400RPM's "extra" before it settles down.

I only notice this happens on the 2-3 gear shift

Only notice this happens on the morning start ups -> I work 8-5, and when I leave at 7 (damn work! :P), I don't see the flare. Okay - it happens after work too. Again, after "warming up", it goes away.

Temp in the mornings are about 48-51'F. Temp when I get off work is also about low 50'F. I think the coldest it gets overnight is 45'F.

in addition, the 1-2 shift is quite hard, compared to normal shifting once the drive-train seems "warmed up".

 

No more flares after about 8-9 stop-signs (why measure in "stop-signs"? because I drive out from a residential area before hitting any business streets 40mph+). This is at the point which I believe the drive train is "warmed up".

 

I assume that since your original post mentioned that it happens when it's cold, that your flares/surges goes away after sometime too?

 

However, when you say surge... does it seem like your tranny is slipping before it seems to get into gear?

This is what I notice on my "surges".

During the 2-3 shift, while driving relatively soft (vs. hard = 55-60% open throttle like accelerating on a highway on-ramp) at about 2500RPM, I'd notice that the RPM's surges to 2900RPM before coming back down.

It almost seems as if the tranny is momentarily rev'ing in neutral before catching onto the tranny gears.

 

If this is what you see... why do people think it's related to the MAF or engine related? It seems more like transmission related to me?

My novice encounters makes me think that the tranny fluid is too cold or something.

 

Have you tried changing your tranny fluid or checked it's condition?

Edited by Qx4donald
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