I have a 95 Ford Windstar 3.8. I have been having numerous problems with it since purchase, however, the problem at hand is driving me and everyone around me insane! When it is running, there is a jerking to it. At speeds of 35-55 it jerks, if you are pressing on the accelarator, it jerks worse. If you slam the accelerator to the floor, it stops, if you let off the gas, it stops. We have sunk tons of money into the thing trying to find the problem and cannot come up with a solution.
We have already fixed:
EGR Valve
O2's
Mass Air Flow sensor
Wires
Plugs
Coil Pack
There are NO errors showing on the scan
Ford dealers cannot figure out whats wrong with it, neither can two independent shops.
Any help will be apreciated!!!!
I have seen that it may have something to do with the Fuel pump relay, but do not know the location of it, so if someone knows where it is, I'd owe ya big!!
Thanks so much
C.

 

Plugged/ bad catalytic converter?
Bad torque converter?

Anyone else?

I'd also post this question on FlatRateTech.com, on their forums. A lot of good help over there, especially on FWD Fords.

 

have you checked the tank to make sure nothing could be impeding the flow when you let off gas it dislodges or when you nail it it sucks it out of the way?? I know the 95 windstar i had was the worst thing i ever drove except for maybe the caravan

 

Ok, a bit more background on this "problem" may be helpful to ya
I took the van to Ford dealer and was told that three things came up on error, the EGR valve, the mass air flow and the o2's. We replaced them, and still the jerking. There are no other errors showing. After the dealer determined "they had no idea" I took it to another shop who proceeded to rip me blind. They saw a woman alone, husband deployed to Iraq and went crazy on my wallet! I don't know what was actually done and what he was crudding me on, since most of the parts he claims he put on are still factory. So.... long story short, we started from scratch all over again, $1500 and still the jerking later.
He supposedly smoked the engine, changed the fuel pump and injectors also, along with the three parts above, however I just changed those myself last week since they were still throwing off errors and were factory parts, dead givaway that the money I paid for those to be fixed went for the down payment on his new hummer. blah!
We have an apt to have the fuel pump changed out tomorrow, and i changed the coil pack today, no help. I'm just going nuts with the whole line from the mechanics that they can fix "this" but it may not be the problem. I was praying that someone out there would know of a problem with them that was causing this.
Oh, and we already had the blown gasket problem and transmission problems and those were replaced via Ford recall as were the brake wires, and wiring harness.
I am registering as we speak with Flat Rate and watching here for any wonderful advice I can find from you all. :0)
Thank you so much for your time
Carol H.

 

Carol- How many miles are on the car? When the car is not moving, with the transmission in neutral, and you rev up the engine, does it seem to miss? Have the motor and transmission mounts been checked? This is a tough problem to diagnose without actually driving the vehicle. And, I for one really appreciate what your husband is doing in Iraq, thank you, and the best of luck to you!

 

The fuel pump relay is in a Master Relay Control Module which is bolted to the front bra beside the radiator just below your head if you look under the hood from the front, on the drivers side. It is a four inch by six inch box about two inches thick. You have to have small hands, and work from under the front of the van to remove it. It contains the relays for the air conditioner (three of those for low cool, med cool and high cool) and a fourth relay for the fuel pump. It is non serviceable and must be replaced as a unit. Costs about a hundred bucks at the dealership. It doesn't sound to me like the problem tho, because it should just fail, and when it cools off, maybe work again. The biggest problem with these was getting moisture in them in the winter, and then when you turned off your vehicle and it cooled down, the moisture would freeze the relay open, so the vehicle would not start. Let it sit for four or five hours, and the moisture would evaporate, even in the cold, and the vehicle would start and run again. Have you checked to see if the oil is contaminated by rad fluid, or the rad fluid shows some oily content? Could be the famous head gasket problem, and it it is going between two cylinders, you may not see external evidence. The lack of codes surprises me, but the 1994/95s didn't have the full range of codes yet. The full OBDII didn't come in till 1996 in Winstars. You are correct in one thing tho. If the problem IS the fuel relay, it won't give you a code.

Thom

 

Wow,As a service tech myself,I cant understand how people can do this kind of stuff,first,let me mention,that in michigan,we have laws protecting you from shady repairs that are not needed,and you should check and see if you can get your money back.But now to your van,I need to ask,has anybody done any testing on the tps,that would be the throttle posisition sensor,I ask because you say this happens between 35 and 55mph,what amazes me is how these guys are tossing parts at your van,thinking or guessing that it will fix it.Every part that you listed can be tested to determine if it was defective or not.I know I would put a fuel pressure guage on it and monitor the pressure while trying to recreate the problem.Another thing,we use a type of monitor while road testing that although will not always give us the correct part that is defective,it does help eliminate the parts that are working properly.I only wish I lived closer to you,I would gladly come over and fix your van for free,after all,your husband is doing us a great service.If I can be of any help,just shout.

 

Does the engine sound like it is missing when in netrual? In netrual rev it up slowly and see if the engine stays smooth. Sounds to me like maybe you are looking at a transmission problem. If it jerks when driving but not under heavy acceleration ir when letting off the gas there is a possibility that your tranny is acting up. It could be the vacumn going to the tranny or even the filter maybe needing replaced or even the pump. It's real hard to tell for sure. But under non-driving conditions if the engine doesn't jerk,lope,or miss I'm thinking maybe trans.

 

It would be nice to know what the O2 codes were when you first checked it. Considering all you have changed, if the codes were for lean exaust both banks, I would look for simple vacuum hoses with a hole in them. It will cause the problems you are having at cruise speeds and not always at idle or full throttle. A small tear in the air intake hose between the mass airflow sensor and the throttle body will do the same thing. Fuel pressure can be tested during the miss which will eliminate changing it just because.

 

I second the throttle position sensor. It was my first thought and King Triton mentioned it above.

 

> $1500 and still the jerking later.

I could change every component under the hood for that price, including the alternator and starter, plus labor, and still have money left over. Only thing that would not be new would be the engine internals

> At speeds of 35-55 it jerks, if you are pressing on the accelarator,
> it jerks worse. If you slam the accelerator to the floor, it stops,
> if you let off the gas, it stops

You are not here, so I can not check it and when I worked at Ford I stuck to trucks and avoided FWD so I do know not much about Windstars. That being said, with your engine, your tranny, the fact you probably have close to 100K miles, and no errors codes

-- > I would suspect the lockup for the torque converter before I did anything
-- > electric. 35 mph is about where they all kick in. This would have been
-- > the first thing I would have checked.

I would not recommend bringing it to a transmission shop, some of them are the worse rip offs. Find a Ford Blue Oval certified dealership. Check with the BBB and make sure they do not have any wierd complaints. Bring it there. Try to get a guy that has replaced 30+ 3.8 engines to take a look at your vehicle or a master tech that has been working on vehicles for twenty years. Even if you have to drive it 50 miles to get there.

 

That being said, if you have not had the throttle position sensor changed (TPS), I would just replace that. As far as I know, there is no feedback to the CPU on that sensor on 1995 and under, so it might not produce an error. Usually it is just two Torx screws, some may require a simple adjustment, most do not. Just take the old one off, put the new one. You might have to disconnect the battery once the new one is on, a real Ford tech can chip in on that.

Autozone:
Wells TPS247 O.E.M. #F48F-9B989-AA, F4ZZ-9B989-A $21.99

At this point, if the OEM TPS was only $10 or so more, I would go with the OEM Ford one from a dealership to eliminate an out of spec aftermarket one. You can use a multi-meter to test most TPS sesnors, though this is beyond a good deal of "techs" that work in most non-dealership enviroments.

BTW: Reason for suggesting this is because your problem is going away at the full on and full off position of your pedal (read TPS), it is where the computer is hunting and locking and unlocking at a variable pedal where it seems to be a problem with the lockup.

 

> Oh, and we already had the blown gasket problem and transmission problems
> and those were replaced via Ford recall as were the brake wires, and wiring harness.

Make sure all the connectors you can see are connected tightly and the wires are pushed fully into the harness and there are no visible nicks or kinks in the wires going to the sensors. If you pull lightly on a wire with a thumb and a finger it should not pull out. Just do not yank it. This will be a real hassle, also check all the vacuum lines, especially the ones towards the back/side of the engine.

Good luck.

 

Jerking as in how?

Does it feel like you are moving along at highway speeds & then all of a sudden it feels like some one has hooked up a tow strap & trying to pull you in backwards but yet your car bogs down trying maintain forward momentum?


Or is it a jumping jerk? Hard to accelerate becasue it is jumping hard but once you get up to speed at it mellows out but you still notice it there?

When you floor it it doesn't jerk bad but you still notice a bad throttle response?

 

I know it is hard to explain things without actually knowing the vehicle or the history.

I read your post earlier about having the tranny checked already. It is is doing what I have quoted above I would then have the tranny checked again.

I had a lincoln with the same engine & tranny you have. I had experienced the problem quoted above & it turned out to be a massive tranny problem. No one could figure it out until I was sitting on the side of the road.