I've searched for any previous posts regarding my problem, but could not find any. If this has already been covered, I apologize, and ask that I be pointed in the right direction.

I have 2004 Crossfire with the standard V6 with only 13,000 legitimate miles on it. As far as I can tell nothing had been done to it: no repairs or tune up. I realize a tune up should not be required at this low mileage, but I had the plugs, wires, air filter, fuel filter, coolant, cabin filter, and oil/filter replaced by a very reputable repair shop, by a mechanic with experience working on Crossfires.

It runs very well now (always did), gets very good mileage (premium of course), and always starts right up. No problems at all, except sometimes, about every fourth or fifth time, when I accelerate hard it bucks badly at high RPM, about 4,000-5,000 RPM for a split second. It's not just a hesitation, but feels like the engine completely cuts out. Other than this, it runs very smoothly. It's always parked in my garage when not driven and does not exhibit any drivability issues other than what I've described.

I put it a can of Seafoam and filled the tank, and am was hoping it's just the Seafoam cleaning out the accumulated gunk built up in the engine, since this car has spent most of its life sitting around, and I admittedly drive it very carefully. But I've put about 150 miles on this tank full so I don't believe it's the Seafoam doing its thing any longer. I'm thinking it may be the fuel pump.

Does anyone have any ideas? Thanks.

 

Probably not the fuel pump, that would be a sputtering, not a complete cut out.
Any codes ?
Could be the connection to the CPS, removed the connector and spray both sides with contact cleaner.
Use an air gun or computer air can to clean out the socket of the CPS before reconnecting.

 

I think you are saying that this problem occured prior to the sea foam treatment and after the tune up. If so I think that it is possible that one or two plugs do not have the cables attached correctly, or the engine cover could be a bit loose.

 

Thank you for the replies, so far.

I'm not sure what a CPS is. I don't have a code checking device, and the check engine light is not on. It's an automatic transmission, by the way.

I've had the car for only two years and, frankly, never brought the RPMs up very high until after having the tune up performed, and after the Seafoam. I put only about 1,500 miles a year on it.

I used to buy used cars frequently when I was young and enjoyed repairing them. But that was a long time ago. All the fairly recent cars are half car and half computer, so I gave up on doing-it-myself. This is only the second used car I've purchased in the last twenty years. And yes, I'm positive the mileage is accurate (~13,000 miles).

I want to reiterate the fact that it runs great in every way (starting, idling, gas consumption, etc.) except when I floor it and take it up to 4-5,000 RPM, when it sometimes (not always) cuts out completely...sort of like I took my foot all the way off the gas. I've already had the repair shop, which I trust, make sure the work they performed was done properly.

This is the only car I've ever bought strictly because I love the way it looks. It has beautiful lines, from every angle. Looks better than much more expensive cars, in my opinion.

Anyway, I'm guessing that even if this problem does not improve, the car won't leave me stranded or even detract very much from my enjoyment of it. Looking back, I realize I should have been driving it in a more "spirited" way, to keep the engine and fuel areas from becoming clogged. It's just that it runs so well except for the intermittent problem described.

 

Seems to be getting worse: it bucks like a wild horse now nearly every time I reach 4,000 RPM. As long as I keep my foot on the gas at that RPM, it bucks. Otherwise, it still runs very well at all times...except for a barely perceptible roughness only at idle, which has been the case in many cars I've owned. In order to rule out the possibility of the Seafoam cleaning effect and also bad gas, I'm going to wait until the gas tank is below a quarter, and then go to a different gas station and fill it up.

It sure feels like the engine is either starving for fuel at that RPM--maybe an injector or the fuel pump (as I originally thought) or something electrical. I don't think one bad plug and/or wire would cause it to buck this badly at high RPM. But I could be wrong.

 

Read back to onehundred80s post. He gave you a couple of good leads that wouldn't cost anything to check. Your mechanic should do it for free since the problem may be his.

 

The mechanic that did the tune up has already checked his work, including the plugs and wires replacement. Assured me they're OK. I'm not sure what a loose engine cover is, but I'll check the engine compartment myself.

The problem may very well have existed prior to the tune up and Seafoam, because prior to the tune up and Seafoam, believe it or not I pushed it to 4,000 RPM and beyond only two or three times. That was over a two year period. It didn't exhibit the problem then, but that could just be the randomness of the issue at that time. But now it's not so random.

 

sounds like incorrect fuel pressure, since you just replaced the fuel filter/regulator I would look in that direction. use a test gauge on the end of the fuel rail, it should be around 55psi

 

I initially suspected the fuel pump, and still do. So thanks for suggesting I check it. I'm going to drive the car a few more days (unless the snow flies first) and will check the fuel pump at that time....unless it's just the Seafoam and/or bad gas, which I'll know more about when I refill the tank. I'm still hoping, but not expecting, that maybe the problem will end with this tank of gas. But definitely not holding my breath.

 

well, if he used the wrong fuel filter/ regulator, it could be starving for fuel, which would make it buck. It gets fuel, doesn't get fuel gets fuel kind of thing. I would certainly take Rob's advise and check into the fuel filter he used. The car was fine it sounds like until he did this. Good luck.

 

Yes, I'm gong to have the repair shop double check the fuel filter, even though I'm fairly confident they installed the right one. I'll also have them check the fuel pump.

As for how the car ran before the "tune up," other than two of three times over a two year period, I never pushed it to 4,000 RPM+ until after the recent work. So I don't know how it would have behaved then at higher RPMs. This is making the diagnosis more difficult.

 

I have seen a lot of Buick 3800s do that and in each case it was secondary ignition (coil wires, coils, plugs) and it has half the number of plugs.


Key is that a secondary ignition problem like that will often only set a P030x (misfire) code while I would expect a fuel pump/regulator/injector to report an over lean condition (P017x).


ps electrical problems often surface with age and not mileage.

 

I appreciate the specificity of your reply. I've been meaning to get a code scanning tool, and this seems like a good enough reason to buy one. I'll see if I can come up with the codes the computer might be retaining and then take the car back to the repair shop. I could always take it to a Chrysler dealer, but that would a last resort. Except when under warranty, I've not had good experiences taking cars to dealers.

 

Cga...does it run fine as long as you don't go all out throttle?

 

Even if I floor it, as long as I keep it under ~4,200 RPM it runs great. There is a very minor misfire at idle, which many drivers would not even notice, and which is not always present. The car really does run well other than the high RPM problem. Flooring it does not result in the bucking until ~4,200 RPM. Always starts on the first try, in a split second. Has never stalled on me, or even come close.

Autozone will check the computer codes for free, which is a nice service. I plan on having that done this week, perhaps today or tomorrow. I'm not sure how accessible the port is, however, and if access requires removing a cover. I think it's on the driver's side, near the door.

 

Yes, the port is on the driver's side near the door, and it does have a pop-open cover.
No problem to get to.

 

Well, you know when we mod these SRT's, we increase the need for more fuel. So you have to upgrade the fuel pump. Our cars will starve for fuel when the higher rpms are reached. Sure sounds like a fuel problem. He could have used the wrong fuel filter/regulator.

 

" I've been meaning to get a code scanning tool, " I just use my Android smart phone, a $12 OBD-II/Bluetooth dongle from Amazon (a mini you can just leave attached, mine has been in there since I bought it). And the Torque Pro app ($5).


Lets me view a number of parameters while driving (coolant temp, spark advance, etc.) and can measure a 0-60. Have paid more for less.

 

My Crossfire is not the SRT version. It's the normally aspirated V6, and I'm sure the previous owner left the car completely stock.

I'm still leaning towards the fuel starving possibility, i.e. perhaps the fuel pump, and/or the filter, or something else causing the engine to starve at around 4,200 RPM. But it could be an electrical issue...

It's a bit odd that it happens only very near the 4,200 RPM mark, and at no other time. And other than a very minor idle misfire, it runs great. If I have time this week, I plan on taking it to Autozone so they can check the computer codes. It would be a lot of simpler if the check engine light flashed, but I guess I'm not that lucky.

 

That's very interesting. Thanks for the tip! I'll check Amazon.