Since it appears the Failsafe problem is in some way related to the temperature, I've taken the advice of a couple of members to use the interior heat to scavenge heat from the cooling sytem. I figure it cannot hurt and might make a difference. So I've been running the heater the last few days.

I also noted in a post a couple of days ago, that since fooling with the relays and electrical connections, I haven't had a Failsafe.

Well I guess I should have made that sacrafice to Lugnut, because driving home last night I had the heat on high (and it was blowing very hot air) and I noticed the rotten temp gauge needle was it's own width above the center mark (which usually is a sure sign of an imminent Failsafe) and then.........

I noticed the interior heater was blowing barely warm!!!

It continued to blow only sightly warm air the remaining 3 miles to the house. I shut if off and tried a restart - FAILSAFE.

I've been advised the temp sensor is really on the wrong side and indicats temp of the radiator coolant and not the engine. If that's true, then it appears as though I have a sticky thermostat, even though I've know it's been replaced twice in the last two months.

But I've not chased down the heater hoses, this could only be true if the hoses are coming off the radiator and not the engine block. If they are coming off the engine, then this theory is goundless. Because either the car is running extreamly cool (not likely) or for reasons unknown to me the heater control is shutting off the hot water flow to the heater coil.

Can someone help me out here? I feel this cold heater air when the temp gauge is indicating slightly hot probably has some significance. I'm just not smart enough to know what that might be.

 

Yes you are correct; my comment to do the vacuum test was based on the P0171 & 174 in your post #52. Thought you were bringing it up again. Just wanted to mention that the vacuum leak is not limited to the engine compartment but the evaporator and gas cap. I should mention the gas cap I think has a recall. This might help http://gusglikas.com/images/AutoRepairPhotos/P0171.pdf As for the electrical diagram this is the complete for your car http://gusglikas.com/images/AutoRepa.../jagxk1998.pdf Something to think about, if you swapped relays you may have placed you problem in another area of the car and would account for the car wanting to start but the battery being low.

 

Excellent point Gus! That thought would have never even occurred to me. I've got to make a point to remember that for future reference.

 

Well, easy way to know if the thermostat is the problem is to eliminate it from the equation all together. You can drive the car w/o one (especially in Hawaii), just don't neglect to let the car warm up for a minute or two before driving. You can also drop your thermostat into a pot of boiling water and watch it pop open (or not if its broken). If you drive the car without it, I'd try doing it with the heat off and see if the car doesn't overheat (I'm pretty sure your engine is running way to hot). But like Gus said, make sure you haven't simply misplaced the problem if it was a faulty relay.

I know for my Jag, there are different thermostats that are listed as the proper ones, when in fact the lowest cost one (around $20), does not fit. I'm not sure about your's, but it could be a similar instance, someone trying to fit the less expensive thermostat in to save a few bucks meanwhile charging you full price on the job. May or may not be, but worth looking into.

 

Mr Fart
Recommend you print(Works printer of course) the Electrical guide that Gus posted the link for, I find it easier to reference in paper copy, also they make excellent presents if ring bound, I gave a copy to the brainless bint I live with for Christmas.....She was over the moon! Anyway, back to another "Try checking" here,s a list of Engine managment componants that share a common to each other.
Inlet Air Temp Sensor
Engine Coolant Temp Sender
Throttle Position Sensor
Mechanical Guard (in throttle body)
Fuel Tank Pressure Sensor
They are commond together in a splice in the engine harness and in connector PI1-pin 6 Black/Green wire. Maybe worth a check if thermostat replacment/removal comes to nothing
Bob
Ps I have 40 days holiday owed to me, What do you reckon the cost of the flight would be from Birmingham UK to Maui? I,d bring a tent and tools......and maybe a thong or two

 

Bob,

No need for the tent. I got a sweetheart deal on a 3 bedroom, 3 bath pole house, about 2400 sq. ft. Which leaves two bedrooms empty and available for guest (although I haven't furnished them yet). It's situated at about 500' elevation about a mile from the beach with a panoramic view of the mountains, ocean and the sunset.

If you want to come help out with the demon car, your welcome and have a place to stay.

And thanks for that troubleshooting info.

Steve (alias OldFart)

 

After a lot of posting and replies, I guess everyone is wondering what happened. The real reason there have been no posts, is that there haven't been any new developments.

The smoke test showed that nearly every gasket on the intake manifold was leaking and the PCV tube was leaking. So there was a wait for parts to be shipped in and they finally came last Friday.

But to my surprise, my regular mechanic, who has always had the time to fit me in, advised that he couldn't get to it until next week, and asked me to come by on Monday. But on Monday, he fessed us that he had sold the shop!!! Said he had to keep it secret as part of the terms of sale. And the new owner advised that the earliest he could get to it was on Wedneday - Today.

I just checked on it during lunch and they have it apart, the new gaskets are in place and they are just starting to put it back together. So by this evening I should have some indicator of whether solving this latest problem is actually going to also solve the Failsafe Engine Mode issue.

Again, thank you all for all the help you've provided. Every bit of it is very much appreciated.

 

Vacuum Leaks!

 

Gremlins. I've got gremlins.

The shop got the new intake gasket set and PCV tube installed. They also disconnected the battery to reset the ECM into learning mode.

The tech started it and then topped off the coolant reservoir. And before the car could warm up it had a Low Coolant Warning. So he checked the violent again. It was full. Checked the flow, it was good. Shut it down, cleared the code. Start it back up....LOW COOLANT WARNING. It was late so I left & said I'd check it in the morning when it was cool.

My commute is about 15 miles. Mostly highway, a few traffic lights. The engine was running smoother, but still a little rough. It seemed to have a little better throttle response also. Since I've been really babying it, I hammered it on the highway for about 5 miles. And it was much smoother at the next stop light.

And just to check, I pulled over & shut it off and then restarted it - twice!! No problems. Then I got home and shut it off and tried to restart ....... You guessed it FAILSAFE ENGINE MODE yet again.

It's driving me to drink.

About all that's left is the MAF, the gas cap, and the wiring harness.

I'll keep you posted......unless I decide to put the car out of my misery and roll it off a cliff. We have cliffs here that it's 1000 feet to the water and then the water is 3,000 feet deep. I'm beginning to like the idea.

 

This might help ... or not. But, it is easy and addresses the symptom directly.

Check the coolant level sensor *and* the float.

The float, according to other posts here, has a tendency to stick. It is apparently some type of floating ring that rides on a rod. The surfaces get contaminated and the sticking starts.

Success in fixing the problem has been had by using a long stick to push the float up and down to unstick it. Something like a chopstick should do it. There ought to be some of those floating around in Hawaii.

You might need to siphon the reservoir out until you can see what is happening.

The background behind this is that there is no way whether the coolant is flowing or not, that the coolant low warning ought to show if the coolant level is up.

If the coolant level warning is triggered, the ECM might *also* see the signal ... and trigger the failsafe.

If the float is okay, move on to the sensor wiring and the sensor itself. The float is easy pickings and a known problem though so try that first. If you have to move on to the sensor and wiring, be aware that the mounting is delicate. Too much force could result in ordering a new reservoir.

Pushing the car off a cliff is not an option until at least one JF member has had a shot at a trip to Hawaii!

++

 

It could be the ECM, i've heard of a few instances of it being an elusive problem after all other avenues are exhausted. I can't recall if i've (or someone else) has already mentioned it though. Anyway you could swap with a good one, just to check? It'd be hard to find one in your VIN range though, or even nearby, I would think. maybe someone could ship you a spare one (tech perhaps?) that would work, as a diagnostic step?

 

Good advice. It's down at the shop right now. They are removing the coolant resevior and will remove the sensor and check the operation and run a conductivity test on it.

Thanks for the tip.

 

I'm only somewhat familiar with ECM's. And the little I do know relates to much newer cars. I have the Sniper Special Forces software and tuner from a previous car and often reflashed the ECM whenever I modfied the engine (which was often). From that limited experience, it was my understanding that you couldn't just plug in a different ECM from the same make/model/year of the car and expect it to work, because the ECM was tied into the security system and the car would not start unless the dealer reprogramed it with dealer only codes/programmer.

So my question is really multiple questions:

1. If I get a new ECM can I just plug it in will it will actually run?
2. Will any ECM from a similar year range work, or do I need one for a like VIN range? And if so, what is the range?
3. Are the ECM's coded (serial numbered) to the VIN?
4. (If the security system or dealer only reprogramming is not an issue) Is my best bet to try to find a OEM new, or is Ebay the best bet?

Obviously I'm out of my depth here, so all of you that really understand this aspect of these cars are being a huge help to me with any information you may wish to share.

Thanks,

 

I noted in one of the replies, that the fuel tank is part of the vacuum system and a faulty gas cap has the potential to cause problems like I'm experiencing.

So I've paid close attention to the gas cap the last couple of times I filled up at the pumps. Now on most cars, when you first remove the gas cap you get a little "whoosh" of air pressure being relieved. But I've noted on this car that there is no sign of any pressure being relieved when you first unscrew the gas cap. And I've even put my face right next to it and listened.

So having no prior experience with this model car, is this normal, or should there be some pressure relief?

(And if it does turn out to be just a bad gas cap, I will console myself for all the money I've already spent by acknowledging that everything that has been done really did need to be done regardless.)

Thanks,

 

Don't pay much attention to that, Steve. The V8 cars generally do not hold pressure in the tank; I'd be more concerned if I noticed the "whoosh".

Cheers,

 

I,ve only noticed a "Woosh" when I,m nigh on empty!As XJR guy says this is probably irrelavent
Bob

 

Steve,
Has the renewal of the intake gaskets stopped the lean codes you were getting?

 

Yes, the lean fuel mix codes disappeared and haven't come back.

And the car is running much smoother. After a 5 mile high speed run to blow out the carbon and push some fuel through the injectors yesterday, it was idling as smooth as a person could want. So I thought that the rough idle issue was also solved.

But today during a lunch run, it was back to being rough again. Not as bad as it was, but noticable enough that you could feel it in the steering wheel.

So I'm wondering if this points to the MAF - or something else. Anyone have any thoughts on this?

And regarding the Failsafe problem that is still there. It's much the same. The car will be fine for a half dozen shut-down/restart cycles - and then for no appearent reason you'll shut down and it will be in Failsafe when you try to restart. You have the codes checked and the only code is P1111 System Check - Pass.

I've thrown so much money at this, that I'm reluctant to purchase a MAF at $386. plus shipping, unless some of you knowledgeable memebers feel it's the next best bet. (And if you do, and it doesn't fix it, I'll not hold it against you. I figure its anybodies best guess at this point.)

Thanks for all your help.

 

Bob,

I've tried a couple of times to print the electrical info Gus posted, and had no success. You noted a "Works printer of course". Could you please help out a dumb old fart and explain to me what a "Works printer" is.

Thanks,

 

Steve,

Refresh us a little. What is the current status of: [new, old, substituted, clean, secure etc.]

Throttle Body
Relays in the RH enclosure by the ECM & TCM
Relays in the LH Eng Compartment fuse/relay box
All the power studs and pass-thru studs circled in the attached page

Been a long thread and need to clarify a few things.

Cheers,