Some like it hot. My SHO does not!

[shojuan]

Well after 650 blissful and code free miles since I performed my 60K my now happy SHO decides to misbehave a little. I went to run some errands today and it turns out we're starting up a little heat wave. After a lot of stops up in Gilroy (I think it was in the low 90's, not too bad but hotter than it's been since 60K) the SHO started to stumble a bit coming off idle from a stop light. Sigh. I was debating whether to do another decarbon procedure because I wanted to try out the Seafoam carbon cleaner formula (right after 60K I decarboned with a can of pourable Berryman's B-12). I decided to clean her out again.

Anyways, I get home and get a bit more stumbling as I'm backing into the driveway then I look down and goody a check engine light! Codes for me to pull! thumbs_u So I pull the codes. KOEO I get a 33 -> EGR valve opening not detected. Pooy! I cleaned out the nostrils for 60K as best I could. Yeah they weren't free of carbon but I had them reamed out pretty good, a nice clear path. Perhaps a chunk of carbon flaked off and plugged the main EGR "sinus" in the intake manifold? Then I start her up to get the KOER codes: 25 -> knock sensor not tested and 91 -> Front HEGO indicates lean. It was idling kind of rough at this point like it has on hot days in summers past so I know the SEFI is going to be BS, but I run it anyways for laughs: 1, 2, 3, 4, 6 hehe. It ain't going to be doing that when I start her up cold tomorrow morning

So I clear the codes and decarbon with another can of B-12 that I still have. Cook. Can of water. Cook. Drive hard for 10 minutes, return. Then out comes the can of Seafoam. Decarbon. Cook. Fire her up, WOW lots of white smoke, the B-12 never did that. Well the seafoam says so on the can that it will smoke. Since it's somewhat oily, I'm not surprised. Can of water. Cook. Fire her up, a bit more white smoke, take her for a nice hard drive, about 20 minutes this time and some back roads to mess around on a bit.

One thing I noticed is a power dip after 4000 rpms in third gear. It seemed to pull fine past 4K in second gear, but in third gear there's a noticable dip. At first I thought maybe it's just some seafoam and water in the secondaries that needed to come out, but that's when I started noticing 2nd gear didn't seem to have the problem. So, I got no ideas about that.

Come back home, run the codes again. KOEO 33 arrgggg! KOER 91 and 25 again. It was idling fine when I pulled up but after sitting a bit while running KOEO, it was getting a bit rough after KOER. Cleared the codes again and will try again tomorrow when it's a bit cooler. If the rough idle comes back tomorrow, I'll reset the computer's idle.

I haven't replaced my HEGOs yet and although I am planning to within the next month or two I was enjoying not having any codes for those 650 miles. Anything else this behavior could be other than the HEGOs or is that likely my one and only problem at this point?

Rick

 

[shojuan]

OK, I let the car cool down from 7PM to 11:30PM. Must be beginning of a heat wave because the intake manifold was still hot. So I take it out for a drive to heat up the HEGOs and then pull the codes. KOEO still shoots out a 33 (yes, after I clear codes I run another KOEO to make sure they're really cleared). KOER sails through with an 11 and the SEFI sails through with a 9. I didn't notice the power dip after 4K in third gear this time either.

So, why doesn't my SHO like it when the weather is hot?

Rick

 

[projectSHO89]

Here's a possibility: The EEC-IV isn't detecting the EGR valve opening, so it opens it all the way, allowing a far greater concentration of exhaust gasses back into the intake stream.

Easy check to see if your EGR code is due to clogged nostrils or a sensor problem: unplug the vac hose that controls the EGR valve, suck on it while the engine is running and observe the engine RPMs.

A clean EGR port and properly operating EGR valve will cause the engine RPMs to drop significantly, possibly even stalling. No change in the RPMs means either the EGR valve is dead or the 'nostrils' are plugged.

If the RPMS did drop as expected, inspect the rubber sample line that goes to the EGR PFE sensor. They get old and rotten and will crack open. If the line is good, it may be the PFE sensor.

I posted a complete dignostic procedure a while back for the 332 error that includes a link on how a Ford EGR system operates. Note that you have the older, single line sensor, not the differential type used in later years.

Steve
89

 

[shojuan]

Steve,

I put a rubber hose on the EGR valve and sucked, idle did die down as expected so my nostrils aren't plugged (wouldn't make much sense if they were, I cleaned them during 60K early this month). I checked the hard plastic lines from the manifold to the solenoid and from the EGR valve to the solenoid. They seem fine. I did a search for your previous post and came up empty. Search for 1084 and 332 only comes up with one result. Search for all user 1084 posts only gives 221 posts going back to July. Can't find your EGR code 33(2) post.

Rick

 

[Red Raspberry]

Hmm, I just put a blocking plate on my intake where the EGR was today. Also plugged off the PCV system. Screw 'em.

 

[projectSHO89]

Rick,

The goofy search feature seems to have a bug in it. Here's the post: http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=001286#000004

The EGR PFE sensor's output should be on the BR/LG (reference 89 EVTM, your colors may vary) wire.

Notice that you have the older OBD-I system, not the OBD-II system which I used as my reference for my post. The off-site link, however, does address testing the OBD-I system.

Good luck!

Steve