Need Some Advice from the SHO Masters

[Chaz1123]

Hello there!

I came across this forum a month ago, and it has helped me out on a few things already, so I just registered the other day! But now I have a new problem I'd like a little help with...

I have a 95 MTX w/ 153k miles.

The car's idle is rough (drops under 500RPM, then kicks back up and repeats) After this it will stall, or I'll give some throttle and that seems to keep it steady. Whenever I take it out of gear (red light, etc.), I have to stay on the gas. On incline I have to set the e-brake to do this. These symptoms are different than the ones for a failing CPS. I know this because I just had symtoms for a CPS and had it replaced about 700 miles ago. Reset the idle a week ago after noticing these problems, with no change.

This morning it had a very rough time starting up. Almost as if it had been sitting in cold weather for a long time (hesitation during crank). Also today, a new symtom has shown up: bucking/hesitation while driving. Makes me have to plan my route around where the best place to break down is!

I'm not geting a CEL, but I pulled codes anyway:

KOEO: 539.....542 & 211
KOER: 538, 536, & 521.....then engine died before stored faults.

Usually if it does stall, it will start right back up again (not possible if CPS failure). But now with this new hard start and bucking under power, I'm worried that one of these times it won't start anymore.

I spent all last night reading threads on the subject and there seems to be more of you pointing to the IAC than anything else, but there has been mention of everything from the TPS, MAF, plugs and/or wires, to sludge in the throttle body, vacuum leak, EGR, and fuel pump, etc. Money is tight right now, so I was hoping the details above will point to something more specific.

Let me know if you need more info,

Thanks Guys, great site!

 

[AutoSHO]

That sounds like a bad winding in the IAB. You can try pulling it and cleaning the passages inside, to see if it helps. Typically, however, when it is bouncy like that, its part of the electronic package that is bad.

All the codes you got in the KOER are little things (turn the wheel, step on the brake, goose test, and the Climate Control on), it did not give anything else.

The 542 means the car has stalled and the 211 is the CPS code.

I would try cleaning the IAB first to see if it has any effect. Does the car have all its usual power once underway? Are there any other driveability problems?

 

[Chaz1123]

AutoSHO:

I would try cleaning the IAB first to see if it has any effect. Does the car have all its usual power once underway? Are there any other driveability problems?

Up until yesterday, yes it did. But now it is bucking and hesitating while driving. I haven't gotten up on the highway with it yet, but so far its doing it in 1st, 2nd, and 3rd. Very minor in 4th, and haven't gotten into 5th yet.

 

[projectSHO89]

The bucking and hesitation might be the CID sensor.

I drove mine for a week with the sensor unplugged until I got around to replacing it. Had a CEL the whole time and it took several attempts to start it almost every time, but it ran perfectly once it started.

YMMV.

Steve

 

[MailManMike]

hey projectsho89 , what part of st.louis are you from ?

 

[sdpatt]

With that 211 code you have at least one failure of the crankshaft position sensor and possibly more since it doesn't always set a code. You state that since the engine immediately restarts, the CPS is ruled out as a cause. Not necessarily.

The CPS usually fails initially in the mode where the engine may cut out for only a split second, or shutdown and immediately allow a restart. It is not until more advanced deterioration of the CPS does it remain in the failure state for longer periods of time.

I don't however, think that the CPS is the source of the low idle speed and stumbling and bucking. With a misfire condition and no ignition related codes other than the 211, you have to take a closer look at the plugs and wires. Non Motorcraft items in these locations can cause misfires.

I would also check out the ground path to the DIS module, the tightness and condition of the terminals of the two connectors attached to it and the health of the DIS itself if nothing else can be identified as the cause.

The low and unsteady idle could be a byproduct of the misfire condition, but that is hard to determine through written communications. If the low idle still exists after solving the stumbling and bucking, try cleaning the MAF sensor filiments and if that doesn't help, possibly replacing the idle air control valve.

After replacement of the IAC valve, the idle speed must be reset. You may even want to try that before any cleaning or replacement just to rule it out as a cause. If you have had the battery disconnected lately, that could be one of your idle speed control problems.

<small>[ February 22, 2004, 10:42 PM: Message edited by: sdpatt ]</small>

 

[Mike Kopstain]

I can almost guaranty this will fix your problem.

Rip off your intake, grab a toilet bowl cleaner (cut the loop in half so you can fish it through the runners), a lot of Berryman's B12 chemtool, and have at the intake.

This sounds like a combination of two problems to me:

1. EGR nostrils are clogged. This would be the cause of the bucking at steady throttle

2. Your throttle body is dirty.

Both of these problems can be remedied with an intake cleaning and I bet you you'll be trouble free.

When looking in the TB opening on the intake you'll see holes where the passage seperates into two. Fill these holes with Berrymans and push something through them.

 

[sdpatt]

Mikeys_Taurus:
I can almost guaranty this will fix your problem.

Rip off your intake...

That will NOT fix a 211 code or a spark misfire. Plugged EGR nostrils only cause an ECC code - not a drivability problem. A dirty throttle body can cause a high idle speed, but not a stalling engine. And you only need to remove the throttle body to access and clean the EGR nostrils.

<small>[ February 23, 2004, 12:59 PM: Message edited by: sdpatt ]</small>

 

[Mike Kopstain]

sdpatt:

Mikeys_Taurus:
I can almost guaranty this will fix your problem.

Rip off your intake...

That will NOT fix a 211 code or a spark misfire. Plugged EGR nostrils only cause an ECC code - not a drivability problem. A dirty throttle body can cause a high idle speed, but not a stalling engine. And you only need to remove the throttle body to access and clean the EGR nostrils.

Plugged EGR nostrils can and will cause a driveability issue, and are the first place I look when someone complains of steady throttle surging, when plugs and wires aren't an issue.

"Ripping" the intake off is what I suggest. If you're going to do the job, you may as well take the intake off, clean the whole thing, and do it right.

The EGR is not sitting there for aesthetic reasons.

 

[Off Road SHO]

Does he have an EGR?

Tom

 

[AutoSHO]

Off Road SHO:
Does he have an EGR?

Tom

I was thinking the same thing...

 

[DHMag]

oil in the plug wells will cause bucking and hesitation in gear, but not in idle. nor would oil in the plug wells throw a code. i say start with the little things first...clean the IAB, MAF, and TB. reset idle. run codes again. the 211 code could be a continuous memory code which was never cleared. what kind of maintainance has been performed on the vehicle ?

it could be a rare occassion that an electrical component (the CPS) is giving warning that its about to fail. normally, electrical pieces wont keep on dropping hints like that. may do it once or twice, then its dead. could be a dirty/loose connection for the CPS or the screws are not tight and its allowed to vary its own gap from the timing viens.

and...EGR on the MTX ? wheres mine ?

 

[Mike Kopstain]

And I'm spent...

Unless it's a CA car, I'm wrong again. D'oh!

 

[Chaz1123]

DHMag:
what kind of maintainance has been performed on the vehicle ?

it could be a rare occassion that an electrical component (the CPS) is giving warning that its about to fail. normally, electrical pieces wont keep on dropping hints like that. may do it once or twice, then its dead.

The CPS failed on the car about 1 month ago. The car would completely die while driving under power, and would not restart for at least 30 min. It has been replaced as of early January. I also had a new IRCM (by the radiator) put in around the same time.

 

[olympic]

A dirty/faulty MAF is my guess. Try swapping in a known good one or just unplug it and see what happens.

Or maybe it could be oil in the plug wells or a problem with the spark system. How old are the plugs and wires?

 

[Chaz1123]

The plugs and wires were done @ 104k. I should get another 10k out of them, I would think.

Intake and TB haven't been cleaned since my 1st 60k. I believe the Ford dealership called it "De-Sluge Engine." Knowing what I know now, I should've had them do the same thing when I had the plugs and wires done. Until the last month or so, I knew almost nothing about the SHO engine, but reading these forums has taught me so much!

Anyway, about cleaning the IM & TB: I'm not one who works on an engine at all. The most I do is top off fluids, replace light bulbs, etc. Taking my engine apart to do the IM is a little scary, not to mention I probably don't have the right tools. I also live in the city and would have to do it on the street!

I need to take baby steps, so I am going to clean the MAF and K&N filter and see what happens. I think I can also do the IAC, if need be. Can the TB be cleaned while on the engine? If not, is it easy to take it off and clean it? If all those fail, I'll take it to the shop and have them clean the intake.

Because the car is so old, I'm planning on getting rid of once I get a new job, and buying a new car. So basically, I just need to get the car up and running again for interviews, and such. Not really looking for long term results.

Any comments?

Thanks for all the help/suggestions up to this point!