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Discussion Starter #1
I have a 2.0 liter dohc, 2003. The problem started after changing the fuel filter originally, so I changed the fuel injectors and the problems still persists. Basically when starting from a stop I have an intermittent issue with my transmissions seemingly slip into neutral if I try to give it too much gas and accelerate too quickly, my RPMs fly up, as soon as I let off the gas pretty much everything seems to go back to normal. the transmission light with the gear flashes once during this and then doesn't store any codes or check engine lights or stay on. There is no fluid that is leaking, but my transmission fluid always seems to have a slight amount of bubbles in it.
I was having issues before changing my fuel filter and fuel injectors with the car having a really rough idle and seeming to be running really slow and underpowered almost.

I replaced the A and C shift solenoids in the transmission a couple days back and the issue seems to happen less, but when put under a load it still seems to do it randomly. There are times when I can drive it and everything seems to be fine, other than a somewhat rough idle.
I was wondering if any of y'all had any pointers towards what it could possibly be? What could cause an issue like that to happen intermittently?

***Also as an afterthought I recently replaced my spark plugs as well. The thermostat is brand-spanking-new and so is the DPFE sensor as I broke it changing the alternator a while back.
 

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Discussion Starter #3
I unfortunately don't I have access to any diagnostic tools at the moment other than what the local auto shop up the road has to borrow to read CEL. What would be the potential outcomes/origin of problem of it being too high or too low of a trim?
to add something as well since posting I had it die while trying to climb up a hill a few times. Was able to put in park and turn off and turn right back on and keep going
 

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I unfortunately don't I have access to any diagnostic tools at the moment other than what the local auto shop up the road has to borrow to read CEL. What would be the potential outcomes/origin of problem of it being too high or too low of a trim?
to add something as well since posting I had it die while trying to climb up a hill a few times. Was able to put in park and turn off and turn right back on and keep going
Without any diagnostic tools you are just guessing.

Also your first post is a bit confusing as you say the problem started when you changed the fuel filter but then you also say it wasnt running right before you changed the fuel filter.

I always like to start with the looking at the basics: fuel pressure, ignition timing, fuel trims, O2 voltages, etc, to get a basic indication of what is right - or not right - and then go from there. Scan tool will give you that data - and more - to point you in the right direction or away from things that are ok.

Also you may have separate transmission issue that is related/unrelated.

BTW 'new' parts dont always mean good parts.

Can you give more basic info:
How many total miles?
How long (time/miles) since last ignition system (plugs, wires, coil pack)?

Paul
 

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Discussion Starter #5
Paul
I meant to say it wasn't running quite as efficiently as I believed it should before I changed the fuel filter and such. I thought the symptoms that I was having with my engine seeming to lack power might be from a clogged filter/injectors possibly. I changed the filter and the fuel injectors and spark plugs in a two day span in an effort to clear up the throttles response.

It has 163,000 miles on it and they were changed in the last week or so. Also just cleaned the throttle body and maf sensor. The coil pack seems fine. No cracks that I can see and it doesn't seem to be arcing. Also took a multimeter to the spark plug wires and the resistance seemed within the specs of a post I had been reading on here. I was tinkering with it today and figured out that when I adjust the throttle up the problem doesn't seem as pronounced.

I wasn't completely hoping to just get an answer straight up but I figured at least digging around for something I hadn't thought of.

I'm currently waiting on new shift solenoids and a new fuel pump. I figured putting a hundred and fifty bucks towards a new fuel pump couldn't hurt seeing as I'm pretty sure most of the fuel system was OEM or at least not touched in the last five years other than basic cleaning/tuneups from what the previous owner said. Also after that point pretty much everything with my fuel system would have been swapped out including throttle position sensor. I'm slowly just working on it as I have the money for new parts.

Are there any good decently priced scanners that you would recommend that could check all of the fuel trim levels and transmission stuff? Or is that just something that is going to be expensive no matter what?
 

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It takes a better scanner to pick up trans codes.

New solenoids do not touch internal trans wear issues and you are likely there with the mileage there.
 

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Paul, I have meant to ask 100 times but is that pic in your posts an old Glidden pro car? Fairmont based?
 

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you need a scantool that looks beyond just the engine codes. need one that can look at transmission codes, which is a different computer

a computer, a copy of forscan (google it) and a cheap ELM327 adapter is great for reading and clearing codes, i personally use the bit more expensive OBDLINK MX ($50-$75) work better if you plan to do programming with it.
 

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Discussion Starter #9
AMC I have read that when a transmission starts slipping that it is not something that will happen intermittently that it will happen every time you shift through that gear. There are times when I can seemingly shift all the way up through all the gear get to highway speeds. Also I've heard that a transmission issue can't really ever cause a car to just die. Is that true?

Huntungd will the second one that you mentioned work on pretty much every model? I had bought two scanners in the past but unfortunately one of them didn't even want to recognize anything about my car other than that it was plugged in. The second one advertised that I could access transmission readings with it but absolutely couldn't. is that something I should speak to the makers of the scanner before I purchase? I was just under the assumption that the OBD2 was universal, is there a different connection for transmission tests or something?
 

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Discussion Starter #10
well, just as an update, it didn't seem to be the shift solenoids. I swap those out with tested working ones and the issue is still there.
 

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Not so on slipping, while slip every time can be common, if a seal ring is involved (worn driver end cover on these) they often can seal right one time and no slip and the next not to leak and slip, as well the spool valves in VB can seize or not when the hardcoat wears off to do the same. The broken servo pin issue on these can easily work right then not work. OWCs can do the same. There are way too many variables involved in shifting to say they always slip or they don't; it is simply not true although it seems to be. Trans simply being low on fluid can flare one time going around a corner and the next not depending on how tight the corner and a difference of a couple miles an hour doing it.

Most ATX use hydro pressure to apply the converter clutch, these are backwards, they use hydro pressure to DISENGAGE the clutch which is applied by a spring, meaning hydraulic fault issues may not do so and engine dies as you come to a stop. The converter clutch being on stopped it. Similar to a MTX clutch.
 

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I hope you've had luck with this. I've only ever owned manual's, so very poor insight as to what could be your problem. But I'll be following along to see what the remedy might be.
 

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Discussion Starter #13
Foush

No luck yet. I did swap out the fuel pump and when it seems to be working the car is definitely getting a whole lot more power to it. The pump in there still had the manufacturer sticker from 03 lol.
The only thing that I can really figure out that I can change that might be the cause or have something to do with it is the valve body for the solenoids if something is stuck in there. Past that I'm probably looking at a transmission overhaul 😕
 

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Discussion Starter #14
On a side note, I'm pretty sure I forgot to do a relearn after I had reinstalled everything. Not sure if it's going to help but once the daughter is asleep and the roommates home I'll be able to do an idle relearn. Wish I had the tools to do a tcm clear/ relearn. Still learning a lot about that whole system. kind of new to cars but completely new to transmissions
 

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Discussion Starter #15
Well got an update from the transmission shop... And my transmission seems to be in perfect health. They couldn't really specify but said that it is definitely something with the engine not the trans. At least the place I go to provides free diagnosis for the transmission.. I'll be sure to update y'all as I find out something from the shop. I've seen quite a few of these forms and everybody always blames the transmission slipping or solenoids. My issue has been verified that it is not with either one of those. So hopefully if they find the fix it may help some of y'all out there.
 

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IF they are right, so many nowadays are no longer. FYI, there is no TCM on those, the PCM only for control there, it had not been separated into another module yet. Pull battery cable for 5 minutes and EVERYTHING relearns.
 

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Discussion Starter #17
The repair shop just got back to me and they said that it is an issue with the PCM randomly dropping the signal to the engine and just shutting off. Basically told me I'm going to have to speak to Ford, that they can't seem to pinpoint it. Could it be a faulty ground or a short in the wiring harness? it does it intermittently so I don't think that it is something with the PCM sending a wrong signal, more so that the signal is getting disconnected randomly when accelerating or jostling the engine from going up a hill.
 

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'...when I adjust the throttle up the problem doesn't seem as pronounced.'

From post #5. Dunno what you think you are adjusting there but likely messing things up worse. The throttle should never be messed with at all, it throws the computer off a mile. That alone done whacky can mess up the trans shifting.
 

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Discussion Starter #20
'...when I adjust the throttle up the problem doesn't seem as pronounced.'

From post #5. Dunno what you think you are adjusting there but likely messing things up worse. The throttle should never be messed with at all, it throws the computer off a mile. That alone done whacky can mess up the trans shifting.
the trans shifting didn't end up being the issue. The issue is that the PCM is basically losing communication to the engine. My fuel trim levels and everything else when it is working are fine. I had adjusted it slightly down due to the fact that I had to replace my entire fuel system and it was idling at about 1200 RPMs after due to everything being the correct pressure and such. I just had it tested and everything is up to spec when the problem isn't apparent. While driving around with the scanner plugged in, the car would literally lose signal from the PCM and just die. The mechanic said that it could be something with the wiring harness or PCM itself. I'm planning on going and grabbing a few diodes tomorrow and seeing if that possibly remedies anything. I was just hoping to gain a little more understanding of how the power management works I suppose.
 
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