[swancott]

I can feel a surge or pluse in the motor at around 45 - 55 mph. No check engine light, just a slight (but noticable) surging. Any ideas on what could cause this? Car runs fine and starts fine.

This is on a 2001 Focus w/ 2.0 Zetec no modifications

I have checked the simple basics, air filter, plugs, wires, ect... all look to be in good shape...

Anyone got an idea or seen something simular?

 

[gitar111]

transmission maybe?? do you have an atx or mtx?

 

[swancott]

This is an Automatic....

Didnt think of that.... It has 48,000 miles and I would guess the fluid is over due for a change...

 

[gitar111]

yeah i would definately think its the transmission then, and the 45-55 range is around where is going into overdrive, so you could have a problem with your overdrive.

 

[swancott]

Let me clearify things a little... Might not make a difference but....

What I say surging at 50 mph... This would be happing when cruising at 50... OD has already engaged.

so If was was just going down the road and held the speed at 45 - 55 mph I can feel the surge at this point.

This is not happening at any "shift point"... Not sure if this could still be an Trans issue, but thought I would through it out there and see what happens. []

 

[breakaway]

At that speed and throttle opening,your auto trans has locked up the converter and you will feel any engine related problems(skips,surging etc) just like it was a stick tranny.Have your ignition checked with a kv tester that measures how much voltage each wire/plug is pulling.OR just replace the plug wires and plugs.Also check you air filter box for rodent debris and make sure there are no leaks on your intake tube assy.I'm betting you have a sour plug wire...

 

[BMARTIN03ZX3]

I had the same problem with startups with the stumble and replaced my dpfe since it was bad. No I've noticed that I have a surging from a certain rpm range, so I replaced my plugs and cleaned my maf, but what I noticed tonight was that the pcv tube has a 90 degree bend that goes into the intake and when I started my car I noticed that the tube starts to collapse, and when you rev the motor the rubber tube will expand and contract you might want check to see if yours does the same. I haven't fix that yet cause it's too late and dark to mess with it but something i noticed.

 

[viney266]

Have you changed the fuel filter as well?? Its gonna be fuel or the tranny, give the tranny fluid a sniff, smell burnt?

 

[UnderEstimated]

Replace the fuel filter and try some fuel injector cleaner. If that doesn't solve the problem, it could possibly be your fuel pump. My girlfriend's ZX2 would surge around 60MPH only then about 3 weeks later, her fuel pump died.

 

[Tbones00SE]

Might be your fuel pump. Do you get these problems, or do they become more pronounced, when you are at or below 1/4 tank of gas? 2000-2001 model years have a recall on the fuel pumps.

 

[BMARTIN03ZX3]

I threw my car on the diagnostic reader at work today when my check engine light came on and it said my car was running lean and I have the surging problem throughout the rpm range so tommorrow or the next few days i'll test the fuel pressure and see what's happening.

 

[BMARTIN03ZX3]

fuel pressure tested perfect so I went ahead and disconnected the upstream o2 sensor and my surging and lack of power had stopped. I think my o2 sensor was getting to many volts.

 

[surgeo1919]

viney isn't the transmission fluid supposed to smell kinda burnt? One day when my dad used to have the 1995 3.8L windstar, the overdrive light was blinking and it seemed like it would try to leave from a standstill point from 3rd gear and obviously the overdrive would never engage causing the RPMs to be quite high. So I guy who I work with has a brother in law who's a mechanic. He came by and did a show and finally smelled the fluid then told me 'ahhh here's the problem your transmission is burnt. I could do it for about $1,500' I was in shock!!!!!!!!! LUCKILY I was listening to the AM radio band and they had a mechanic taking calls. She mentioned that tranny fluid was supposed to smell like that and it's a scam when people tell you need to fix/ replace a tranny to a burnt smell in the fluid! It turned out to be a $50 Virtual Speed Sensor and it was fixed in Montreal's most reputeable tranny shop.

 

[spins]

Well transmission fluid isn't suppose to smell like something burnt. It should be a redish color. Is shouldn't be brown, if so. At the very least it should be flushed and changed. This should be done every few years if you live in the city and do alot of stop and go driving. An aftermarket tranny cooler would hurt any either. Heat kills auto trannys.

 

[rangers305]

yeah im havin the same problems, i have a lack of power and it faintly surges at 45-55 mph

 

[luvachevy2000]

ima tell what it is and its the fuel pump.lucky for you its on recall and ford will take care of it.same thing happened to my car around 50 mph i looked it up and turns out the lil filter on the bottom end of fp has a tendacy to collect alot of garbage and clog things up.call ford dealership and tell them you want the recall replaced.they cant charge you a thing for the recall so dont worry about charge.recall is for the 2000 to 2003 april good luck hope that helps you

 

[fun2driv]

I have the same problem. 01 ZTS 154000 kms. Trany fluid was replaced a while ago so I doubt that. I had the surging and it was due for an oil change so I changed it and shortly after my engine check light came on. I suspect the O2 sensor but I wont know for sure until I have the code read.

This car has become a big money pit because I believe a CV joint just went too! [?|]

 

[jaimz]

lol to me you said 2001 that's an automatic alarm for "FUEL PUMP!"

 

[fun2driv]

Could be. Will know for sure 'cause it just blew a coolant hose this morning on my wife so the money pit (the car) is on the way to the shop.

[?|] For sale '01 ZTS 154k kms, located in GTA Ontario, new tires, winters on steel rims, tons of recent maintenance, $6500....[?|]

 

[PDQEagle]

Too much talk about transmission problems, which have little meaning related to his problem. Back when autos first went to FI, there was a lot of this, because the supporting electronics wasn't the best. Like in the carburetor days, this sounds like "lean surge" like it's hunting for fuel. Check the throttle position sensor (or whatever ford calls it) When this is on it's way out, it gives erratic readings to the cpu, which transmits to the injectors. It doesn't take much of a signal variance to cause this. Additionally, check the exhause sensor, but if they start to go bad, the signal will be off constantly most of the time.