Help Solve a Mystery!

[EF XR8]

Help solve a mystery!
Hi
I have just rejoined the forum after an absence of a few years in the hope that one of the grease monkeys out there can help with a problem that has stumped just about every mechanic in Canberra.
I have a 1995 EF XR 8 with 130 000 kms on the clock. The car was a police car at one stage. It has cruise control that has never worked. The car has a major idling issue that noone can fix. When cold the car will start OK and idle OK for about 30 seconds before starting to idle rough. This continues for the next minute or so, getting progressively worse until the car almost ‘chokes’ itself before suddenly clearing and running fine. If I drive the car in that time without letting it go through the whole process before driving off it is dangerous because it is almost impossible to accelerate beyond 1500-2000 rpm. If I have to accelerate faster than that the car will miss and cough (almost sounds like a muted backfire but in the engine bay itself, not out of the exhaust) before it clears and runs OK. When it ‘clears itself’ it will surge forward, regaining some of the zip that an XR8 should have.
The idling problem happens again as soon as I turn the vehicle off, no matter how warm it is i.e. I could drive it for 3 hours, turn the car off and then back on again and it will immediately go through the whole ‘idling rough’ routine again
I have replaced oxygen sensors, the air intake system, inlet manifold gasket, distributor, exhaust system, have had the computer checked and rechecked, plugs, leads, timing, ignition all done, some of these have been done several times. This idling and surging problem has been with the car for years now and was experienced to a lesser degree by the previous owner. He also replaced the computer, air flow meter, plugs and leads in an effort to address it.
If you have had any experience with this model I would love to hear from you as this is my family vehicle and it is getting too dangerous to use. As I say, many reputable mechanics have had a go at the vehicle and none have cracked it. I’m hoping the Ford Forum can provide some ideas.

[GT-E]

I would be looking at the fuel system. Filter, regulator or pump.

[EF XR8]

Thanks, I forgot to mention on my initial post that the fuel system has been checked over as well. Would be glad to hear any other suggestions though.

[xisled]

May be a vacuum leak.

[Mickxr8]

Cat converter ? (have seen these things play merry hell with cars)

[EF XR8]

thank for both those posts. have had a vacuum leak already tested for. The converter has also been checked when I did a recent exhaust repair. As you can see, it is quite a puzzler!

[Gobes32]

Would be interesting to have the car "chipped" as such so that the factory computer no longer controls fuel/air mixture etc.

[EgoFG]

I reckon that the Car is tuning itself - I really cant recall the extent to which the EFs do this.

I would suspect that the power to the memory of the xxx (thingy that remembers the tune state) is being lost - perhaps a wiring problem, or there is a dud tiny battery there somewhere.

This would be the equivalent of a dead BIOS battery on a PC.

Given that the Cruise is also not working, it might be related to the "Rip out" of the police gear.

[The G6ET Spot]

Has the throttle body been checked?

[foxtrot3]

Hi. Have the injectors been removed and checked for leakage? An injector with a slight dribble when it is meant to be shut wont affect the running of an engine once cleared but when the engine is shut off will dump a bit of fuel onto the back of an inlet valve and richen the mixture of one cyl enough to throw out the o2 sensor until every thing clears Cheers MD

[AWD Chaser]

Originally Posted by EF XR8

Thanks, I forgot to mention on my initial post that the fuel system has been checked over as well. Would be glad to hear any other suggestions though.

Does this mean they replaced the filter or just checked it?

Make sure you have a new filter in there...

[lamborghinifan]

maybe a long shot, but i've heard of two cases of an "untraceable" problem, one on my fathers nl fairlane. similar sorts of idling/tune issues , it ended up being a bad earth on the computer. for the relatively small cost it's worth a look.

[Bundy]

I gave up reading after you said "grease monkey" .............

[mik]

i would re check the cat if nothing changes(even dropping the exhaust ), also earth at the ecu and every where else, maybe even check fuseable link and engine loom connectors/connections, if all else fails, one by one re check all work done, good luck.
.

[RAREV8]

I had this issue with my XC that was fuel injected- try removing all injectors and either sonic bathing them before fitting new olives or replace with new items.....not sure on cost for EF ones though. Given how much has been thrown at it already, dare I suggest an complete motor transplant for something newer?

[Gavin Thomas]

Originally Posted by bundy

I gave up reading after you said "grease monkey" .............

++++++++++++++++++++++++++++++++++++++++++++++++++

So did i .....not a very favorable or appreciated term to use nowadays - which is a little unfortunate for ol' mate as i have seen a very, very similar fault 1st hand myself. ( And also found the eventual fix - which was relatively quite simple in the end ).

Just to be a nice little 'monkey', i'll feed you a little banana by saying that another member above could be right on the money.....

[rag top]

Originally Posted by EF XR8

I have just rejoined the forum after an absence of a few years in the hope that one of the grease monkeys out there can help with a problem that has stumped just about every mechanic in Canberra.

Who in Canberra have you tried? I've found Dyno Tune in Belconnen to be able to trouble shoot bizarre issues on previous cars of mine that workshops and dealerships could not.

[familybus]

you say cruise control has never worked?

do you know why?

i ask because mine was doin the same and all it was, was the little sender unit on the end/side of the brake booster that was faulty!

replaced that and bingo cruise control works and now runs sweet

[roberts]

was the car a repairable right off, bad earth?

[roberts]

I should clarify my question, when cars have been in major accidents and are fixed panels guys get the body looking sweet but don't understand wiring, and mechanical stuff why would they know 3 different trades. I have seen countless cars present with head scratching problems after a major accident repair, so yeah thats my question

[XARATE]

+10 points to EGOFG :-) as an auto elec i second his comment. Take it to an auto sparky and get them to do a back probe of the ecu, they will measure all voltages, earths, outputs, inputs, signals ect amd compare them to a readily available diagram with ecu pinouts and wgat they should have

Good luck with it

[vanman_75]

a low voltage issue im guessing , check earthing to said ecu , and voltage drops in general.battery condition ,and its supply .but many of the above answers are all up there ... write a list and tick it off .


and people get upset from being called a" grease monkey" ? wow the bullying is unbelievable .

[Hitman]

Yes, 'Grease Monkey' is now a defunct term, most 'Automotive technicians' nowadays wouldn't have a clue what to do unless the laptop they have plugged into the car tells them what the problem is.

grease monkeys of old could fix a car without a laptop to tell them what the problem is.

[Ringo]

Interesting problem. You have to think about what is happening in the first 30 seconds on a cold start. Car is running rich (to compensate for no choke) until it gets some heat into it and can start to to back off the mixtures. In the mean time it idles low so the ECU adds some air to get the idle speed up so there is your surge.

Perhaps it is simply the engine temp sensor or wiring into the ECU being damaged sending weird engine temp signals to the ECU.

I am an ex grease monkey...and at the time when I was a monkey I didn't like being called one beause it doesn't get you credit for having some skills. Usually the people calling you grease monkeys weren't looking for you to help them fix their car either. 'Technician' would be the more appropriate term and in the case of this thread 'Princess' may also!

[Gavin Thomas]

Wow - some people here should take a chill pill.... it's all some light hearted 'tongue in cheek' stuff on a internet forum,

Don't take it all so seriously guys - old mate will get plenty of 'expert' advice from plenty of KEYBOARD MONKEYS quicker than you can say "fool-injected",

Besides, i believe i may possibly know a very likely possible cause of the concern / fault / problem at hand = ( Grease monkey lingo for those that are having difficulties understanding ). Also with that in mind it would seem that ol' mate needs me more than i him....Maybe i will give my suggestions in due time. Besides, look how much info / advice has already been given. No one can say which way all this advice will be taken / used. At the end of the day the vehicle will still need to be taken to someone to have any one or all of these suggestions "tried out "..... Maybe the best advice given so far is that from "rag top". I mean really with all the stuff already done, how can we really be expected to give a fair diognosis without even having the car on hand.

Now in the real world, go into any decent Workshop and ask to speak to the head grease monkey & see how you go, Lucky this is the cyber world & my skin is thick enough to realize that the op's remark was not meant with any malice or in any untoward way....Just giving some free professional advice on the best way to start his question, that's all,
Maybe some of you guys need some concrete cookies,

[LOW_NL]

i think that when the op used the term "grease monkey" he was actually meaning somebody with "knowledge" and didn't mean to offend anyone.
and he is asking for help and not to be bullied or lectured in any way,

good luck with finding the problem

[Gavin Thomas]

Originally Posted by LOW_NL

.....i think that when the op used the term "grease monkey" he was actually meaning somebody with "knowledge" and didn't mean to offend anyone.... he is asking for help and not to be bullied or lectured in any way...

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

N/S shirlock ! - And i can't see anywhere on here where there is any real serious bullying..... I realize the fact that you are just trying to stir things up, so get back into your box again,

[RG]

A bad earth would be the first place I'd look. From there I'd try to get my hands on another ECU from a known running EF XR8 as, from memory, the EF did suffer from an ECU fault that affected idle.

If you have no luck there the next port of call would the the MAF and throttle body, a quick clean with CRC Throttle Body cleaner may help here if there is a buildup in either. Still no luck then try the Idle Speed Controller, although I have my doubts about that being the cause as it is, as described, an intermittent fault that occurs at specific times.

To me though it really seems to be related to the ECU, it's almost as if it is forgetting its idle and has to relearn each and every time you fire it up. First 30 seconds would be fine as it overfuels for that period but then as it starts to lean out it isn't sending the correct signals and has to relearn.

And as I type this another idea comes to mind, a leaking injector. A leaking injector will cause the issues you are experiencing.

[SEZ213]

Is this happening only when the air outside is cold? Or at all stages during the day?

When you've taken it to said mechanics, is the issue occurring with them as well, or are they finding no faults and just 'replacing' bits that could be the problem?

[last fairlane]

Hi your not running on LPG are you?
as I had the same problem and it was traced back to
the tap on the LPG tank that was dirty
just a thought
John