97 Ford Taurus..

ej1619

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#1
Has the 3.0 auto with around 188k on the odometer. This thing has me banging my head against the wall. First I had the o2 sensor codes, well being the slacker I am I waited and finally got around to it yesterday. Swapped them out at the same time swapped the egr valve, the egr control solenoid, egr valve assembly, the IAC and finally the tps. The IAC plunger was seized as was the egr valve. The other parts were not in spec when I tested them. Now to the issue, after replacing the O2 sensors the engine started running rough at idle, you can smell fuel fairly strong and it's just sucking gas down, this prompted me to check the other sensors. I found a vacuum leak today and replaced all the hard plastic vacuum lines only to have the same problem. At idle the idle speed is roughly 900 rpm's, sounds like its skipping, when you first take off if you hit the brakes you have to stand on them. When you hit a stop the car surges and jerks, take off again and it runs great. In fact it's never run better in the top end. Also since all this the transmission doesn't kick down properly, this may be totally unrelated all it does have a little slip between 2 and 3. So I swung into the parts house and had them scan the codes, I didn't get the actual codes but there were two; lean on bank one lean on bank two. I know that a bad or dirty maf sensor, and or possibly one or both engine temperature sensors could cause this. So I have a couple questions, is there anyway to check these? Bench test so to speak. Also, why would the engine go to running like this after the O2 sensors were replaced? It ran much better prior to replacing them. I am completely confused at this point. I have no issues replacing the parts but I need to know how to check them first and oddly enough I can seem to find a bench test for the 3.0. Any advice or thoughts on this would be great as I need to get this thing right, we handed this car down to my daughter and I certainly don't need her breaking down.
 
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#2
The IAC plunger was seized as was the egr valve.
With this problem would start off with an engine compression test first, valves are probably warped. Really screws up vacuum.
 

nickb2

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#3
Ok, first off, hello.

Next, and I am trying to be polite here. But that huge block/paragraph/chunk of writing was very confusing for me.

You say you have lean codes on both banks. Correct? I am french canadian so be patient with me and write in a more precise fashion. I will help you the best I can.

I will post back with lean code trouble shooting charts for this engine. If you could post exact codes, that would be awesome. Not to be a prying guy, but are you on a budget? Cuz a cheap scanner can be bought locally and will benefit you in the future for OBD2 protocols.

First of all, is this 3.0l a flex fuel? A dual over head? etc. Because there are 4 engines that they used in these 97 models, and others also. 8th number on vin tag gives specific engine usually. Post the vin #.

I do not have my white ford alldata disk, maybe I lost it. I have time on my hands and will find more info for you. :thx

This not specific to your model but may informative. If you have a P0171/P0174 then check this you tube video. Hope it gets you on track. :thxhttp://youtu.be/Ujt56nnw-2k

If you have no diagnostic skills, this may be confusing. So keep at it, and post back. WE WILL HELP YOU FOR FREE, but I won't go fix it in your driveway for free :ROFL That was a joke BTW. :thx

In the link I provided pay particular attention to comments at the 8minute mark in the said video. Hope this helps. ;D

At the other wrenches here, still did not get my bluetooth interface. ouch But you gotta love what you can do with a laptop :thx
 

ej1619

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#4
Sorry about the crazy format, I am using my smart phone and sometimes they aren't so smart.

Forgive me for not being more specific on the engine. It is not flex, nor doc it's the standard used in 97% of these cars. That said it is vin code "u".
 

nickb2

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#5
Ok, U vin# for engine this helps. Was that video informative for you, or do you need more assistance? Can you post the codes you have.

We have yet to see those. Is the engine loping, such as idle being erratic? thing's like that. I would strongly suggest looking at vacuum. Do you know how to do that?

These engines are like 3.8/3.4l gm engines, intake gasket leaks galore!!! :idea:

Push rod engines work great, do not cheap out on gaskets. Post back reading's if you have a vacuum gauge and describe in a better way exactly what you are experiencing, because obviously, swapping those O2's was costly and ineffective. Look elsewhere.

Because lean on both banks is indicative a leak in intake system, unless both exhaust manifolds leak.

Honda civic's are notorious for this lean condition, the pre cat O2 always has a crack in exhaust manifold.

So you have some research to do, or suck it up and go see a respectable shop.

Keep in touch, we will help you along. :thx
 

ej1619

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#6
I am quite capable of checking all these things, that isn't a problem. I am going to pick up a scanner today and will post back with additional details. I will perform a vacuum check as well as fuel pressure check. I have checked high and low for vacuum leaks. All around the intake, vacuum lines and orifices and such. I had one line leaking so I did replace all of the hard, brittle plastic lines.

As for the rough idle, it sounds exactly like a big block engine in a hot rod, loping and kind of skipping. I will try and get you guys a video of it idling later, it's flooding out there now(not literally).
 

billr

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#7
Get a scanner, or PC link/software, that will display live-data.
 

ej1619

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Ok, I've done some more checking. I've found an exhaust leak or 2. Both are on the rear bank one at the donut gasket the other is where the egr tube feeds from the manifold. Codes 0171 and 0174. Could these leaks possibly be the culprit? I'll try and post some pics of the location in a bit after it cools down a little.
 

nickb2

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#9
Ok had a few beer's with some buddies. my response may not be so kosher. http://youtu.be/ShSRZ_meF-I

Yes these leaks are most likely culprit. :idea: :thx

Always look to post/aft cat leaks for lean condition. Did you check vacuum?

The limk was to motivate you, I am catching a glow. Cars are easy to fix once you get how they are engineered, but I would still check out intake/air system. :idea: Here is me sipping a bud for you. 8)
 

ej1619

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#10
Yeah, I used to work in a shop back when if it didn't run right you adjust the carb, timing etc.. If you had a vacuum leak it hissed Luke a rattlesnake. So I'm a bit experienced just not so much with the current obd II systems... I'll put it in the air tomorrow and attempt to fix these leaks. Hopefully I don't find a cracked manifold...
 

ej1619

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#11
Ok, I ran a vacuum check, it's pulling -5 all around. Fuel pressure is 15 psi..
 

billr

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#12
What does "-5 all around" mean, is that 5" Hg of vacuum? Is that at idle, or all speeds and loads??? Did you ever take compression? Can somebody confirm that 15 psi fuel pressure is OK? Sounds way low for port injection, a bit high for TBI...
 

nickb2

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#13
Can't sleep, too many beer's :ROFL From what I know, it should be around 30-40psi at fuel rail port. At 15 psi, I am surprised it even running. Some ford's go up to 55-65psi to run.

Ideal vacuum should be around 20pouce mercure/hg and needle needs to be stable. At -/+5hg?, I don't think this car running well at all and with only 15psi a fuel rail port?? Maybe check back again.

5hg indicates vacuum leak or late valve timing etc. Here is a good informative video I found to educate others to what I am saying. http://youtu.be/SdlNwm8OHco

I use a vac gauge all the time, it is my next best friend next to my DVM. A good scanner also, but not every one has one. A cheap kit will do for the dyr. For shop use use I have my old snapon in my tool box, my home kit is this old equss kit. I don't know if they sell them anymore, but it came with vac/comp/timinglight/remote starter and dwellmeter/rpm etc. Great kit for small job's.

I am not 100% sure for the fuel pressure, still can't find my white ford alldata disk. But memory tells me it should at least 30psi engine running. Hope this helps, and others will probably chime in also. Cheers. Don't drink to much, hurts the head. Oh, and don't drive. :thx 8) :eek:
 

ej1619

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#14
I double checked vacuum this morning and realized I misread the gauge it's -10 hg. With that I'll keep poking till I find the leak since I don't have a smoke machine. The fuel pressure, I checked at the rail again and again it's 15 psi. Assuming that that is low, would that be the regulator? I'm thinking I need to check it being the fuel filter to confirm.
 

ej1619

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#15
Oh one other thing I found out last night, just by happenstance, this car has California emissions. I don't know if that makes a difference or not, just thought I'd update that.