Old Englishman

[ManwithX6]

Ich entschuldige mich noch einmal für das lange Schweigen, ich bin nicht gut in Websites.
RX-7 SA: Vielen Dank für die Erinnerung an den Schlüsselabgleich. Es scheint hier Firmen zu geben, die das auch tun. Ich habe ein Haynes-Handbuch für einen 626 bestellt, ein Modell von 1992 ohne V6, aber es könnte einige Hinweise geben, die den niedrigen Preis wert sind.

Es ist fast 8 Wochen her, dass unsere Xedos ausgefallen sind und die Garage langsam war. Ich habe das Steuergerät mit 4 Anschlüssen gekauft, aber der Mechaniker kann das alte nicht finden, nachdem er unter den Teppichen und der Batterie usw. gesucht hat, hat aber drei weitere kleinere Kästen gefunden. Die örtliche Mazda-Werkstatt schlug vor, dass es sich unter einer Platte auf dem Beifahrerboden (linke Seite in Großbritannien) oder vor dem Schalthebel befinden sollte.

In der Zwischenzeit hob der Mechaniker die Abdeckung über den Nockenwellen-Zahnriemen, von dem ich nicht bemerkt hatte, dass er Risse hatte, und stellte fest, dass der Spannungseinsteller kaputt war und den Riemen locker ließ, sodass „er über die Zähne der Nocken gesprungen wäre und die Ventile verbogen wären!“ ” Würde das Design das zulassen? Er hat keine Zeitmarkierungen überprüft. Meine Lotus Elan-Nockenwellen sind kettengetrieben und es ist unmöglich, die Zähne zu überspringen, ohne ein Kettenrad zu entfernen. Der Riemen und der Spanner wurden 2017 ausgetauscht; Warum sollten überhaupt zwei schwerwiegende Fehler gleichzeitig auftreten? Der Mechaniker will offensichtlich nicht weitermachen und ich suche nach einer anderen Werkstatt, um die Arbeit zu Ende zu bringen. Vielleicht findet der Weihnachtsmann eines oder schickt ein Rentier mit sechs Beinen in einer V-Form!


Once again, my apologies for a long silence, I am not good at Web sites.

RX-7 SA: Thank you for the reminder about key matching, there seem to be firms here who do it too. I have ordered a Haynes Manual for a 626, a 1992 model without a V6, but there might be some clues worth the low price.
It is nearly 8 weeks since our Xedos failed and the garage has been slow. I bought the ECU which has 4 connectors but the mechanic cannot find the old one after looking under the carpets and battery etc but found 3 other smaller boxes. The local Mazda garage suggested it should be under a panel on the passenger floor (left side in UK) or in front of the gear lever.

Meanwhile, the mechanic lifted the cover over the cam timing belt, which I hadn’t noticed was cracked, and found the tension adjuster was broken leaving the belt loose so “it would have jumped teeth on the cams and the valves would be bent!” Would the design allow that? He hasn’t checked any timing marks. My Lotus Elan cams are chain driven and it is impossible to jump teeth without removing a sprocket. The belt and tensioner were changed in 2017; anyway why would two fatal faults occur at the same time? The mechanic clearly doesn’t want to continue and I am looking for another garage to finish the job. Perhaps Santa Claus will find one, or send a reindeer with six legs in a V!

[Mazda RX-7 SA]

Zitat von ManwithX6

RX-7 SA: Thank you for the reminder about key matching, there seem to be firms here who do it too. I have ordered a Haynes Manual for a 626, a 1992 model without a V6, but there might be some clues worth the low price.
It is nearly 8 weeks since our Xedos failed and the garage has been slow. I bought the ECU which has 4 connectors but the mechanic cannot find the old one after looking under the carpets and battery etc but found 3 other smaller boxes. The local Mazda garage suggested it should be under a panel on the passenger floor (left side in UK) or in front of the gear lever.

The ECU of the Xedos is located directly before the shift lever, down under the radio.

Zitat von ManwithX6

Meanwhile, the mechanic lifted the cover over the cam timing belt, which I hadn’t noticed was cracked, and found the tension adjuster was broken leaving the belt loose so “it would have jumped teeth on the cams and the valves would be bent!” Would the design allow that? He hasn’t checked any timing marks. My Lotus Elan cams are chain driven and it is impossible to jump teeth without removing a sprocket. The belt and tensioner were changed in 2017; anyway why would two fatal faults occur at the same time? The mechanic clearly doesn’t want to continue and I am looking for another garage to finish the job. Perhaps Santa Claus will find one, or send a reindeer with six legs in a V!

There are some reason why something happens.
Many times the tensioner won't be changed in case of new drive belt. In such case everything is still OK, "just" the tensioner failed and in such case the belt can jump teeth.
But, the V6 in the Xedos is a so called "Freiläufer". It means, the piston don't touch the valves in case of belt failure.

[JWBehrendt]

@ManwithX6

Hello again,
well, as far as I remember You have 2 Xedos 6 with the V6 Engine.
With this Engines, it is nearly impossible, to damage Valves!

Between the Pistons and the Valves is enough space, to avoid (nearly) any Collision. There is only one possibility to get the Valves damaged, totally worn out Crankshaft Bearings (or somebody someone intended to grind the cylinder head to increase the compression ratio). This means in a reverse conclusion, the Engine was running without Oil or has been used for far more than 250.000 Miles.

A not working timing Belt Tensioner is no.t an urgent Problem, I drove some 1.000 Miles with this Problem with my 626 V6, because I couldn't identify this terrible noise. By the Way, the Engine ist still running well.

In general, you should check whether the engine can still be reactivated and if so, at what price.

Regards,
John

BTW, the Original Mazda Sparepart No's I gave You, were for the complete Fuel Pumps, with all the neccessary Filters, etc.

[Mazda RX-7 SA]

Zitat von JWBehrendt

A not working timing Belt Tensioner is no.t an urgent Problem, I drove some 1.000 Miles with this Problem with my 626 V6, because I couldn't identify this terrible noise. By the Way, the Engine ist still running well.

But if you know, that the belt already jumped teeth its not an good idea to drive the car.

[JWBehrendt]

Zitat von Mazda RX-7 SA

But if you know, that the belt already jumped teeth its not an good idea to drive the car.

Well, of course You are right, but it's really not necessary to call for the RAC.
The Belt jumped 2 or 3 teeth; Under normal conditions no loss of performance was noticeable and the exhaust gas test (TÜV/DEKRA) was successfully completed.

[ManwithX6]

Fantastisch, danke euch beiden, wie schade, dass ich die Fragen nicht schon vor ein paar Wochen gestellt habe, damit ich wusste, wo das Steuergerät ist und dass die Ventile sicher sind!
Wir hatten zwei Xedos, aber nicht gleichzeitig; Der jetzige wurde 2016 gekauft und hat weniger als 30.000 Meilen (50.000 km) und jetzt sind es 52.000 Meilen.
Zeitet das Steuergerät die Zündfunken? Mein Mechaniker ist der Meinung, dass der Motor ohne ihn starten sollte (er behauptet, er hätte ihn umgangen), wenn er den Motorstart in den Lufteinlass spritzt, aber das tut er nicht, weshalb er denkt, dass die mechanischen Teile defekt sind. Ich kann nicht sehen, warum es ohne Eingabe von den Steuermarkierungen am Motor starten sollte.
Nur aus Interesse: Arbeiten alle Einspritzdüsen zusammen oder werden sie einzeln wie ein Dieselmotor gesteuert? (Ich kann mich nicht erinnern, wo die Injektoren eingebaut sind).

Fantastic, thank you both, what a pity I didn’t ask the questions a few weeks ago, so that I knew where the ECU was and that the valves were safe!
We have had two Xedos’s but not at the same time; the present one was bought in 2016 showing less than 30,000 miles (50,000 km) and now it is 52,000 miles.
Does the ECU time the ignition sparks? My mechanic thinks the engine should start without it (he claims he has bypassed it) if he squirts Engine Start into the air intake, but it doesn’t which is why he thinks the mechanical bits are broken. I can’t see why it should start without some input from the timing marks on the engine.
Just for interest, do all the fuel injectors operate together or are they controlled individually like a diesel engine? (I can’t remember where the injectors are fitted).

[Mazda RX-7 SA]

Zitat von ManwithX6

Does the ECU time the ignition sparks?

Yes! Sure.
Through one signal to the distributor.

Zitat von ManwithX6

Just for interest, do all the fuel injectors operate together or are they controlled individually like a diesel engine? (I can’t remember where the injectors are fitted).

They are individually connected to the ECU via 6 cables. So they will work correctly for each cylinder.

[JWBehrendt]

Zitat von ManwithX6

Does the ECU time the ignition sparks?

Yes.

Zitat von ManwithX6

My mechanic thinks the engine should start without it (he claims he has bypassed it) if he squirts Engine Start into the air intake, but it doesn’t which is why he thinks the mechanical bits are broken.

No Way! There are some ways to do generate an ignition signal, but the distributor is not able to work w/o the correct signals; Means, he has to make a 4-Stroke-Ignition from scratch to emulate the Engine-ECU with all it's Sensors.

Zitat von ManwithX6

I can’t see why it should start without some input from the timing marks on the engine.ignition distributor
Just for interest, do all the fuel injectors operate together or are they controlled individually like a diesel engine? (I can’t remember where the injectors are fitted).

Of course, they are individual controlled.
Are You shure, Your mechanic knows, what he is dealing with?
We left the 70ties far behind, no more contact operated ignitions, no more mechanical Injection-Pumps or even Carburetors!

[JWBehrendt]

@ManwithX6
It seems, we are groping in the Fog; Did You have already been to Your Mazda Dealer to readout the ECU's?

In case, You want to DIY, have a look to our Xedo-Wiki, there it is explained, how to readout the ECU's and interprete the error codes.

If You got the error codes, let us know please.

Regards
John