limp mode???

[ossie cossie]

UPDATE.

Ok. went down today and carried out a continuity test from the ECU pins out to its various end points. After a lot of messing about, found that during the engine rebuild (after the head gasket went) somehow the distributor phase sensor plug had been put onto the knock sensor and the knock sensor plug was on the distibutor phase sensor, (both 2 pin plugs) However after changing these back to theyre correct plugs the car now wont start (it was running before just wont rev above 4000rpm) After talking to my mate he says that during the rebuild, the distributor was taken out, and may not be correctly put back in.
But why was it running?????
I have a couple of questions for anyone who knows about cosworth engine wiring.
Firstly. the distributor, when i take off the distributor cap, rotor arm and dust guard off, the shaft inside only has 2 lugs on it that pass the distributor phase sensor. Is this correct? if so which is the one (of the 2) triggers the coil.
It also has kent cams on it and i can not see any timing marks on them, can anyone help with this.
If the engine temp sensor (the 2 pin one that goes to the ECU) has the wires reversed will this give the wrong value to the ECU.

I think it may now just be an engine ignition timing problem, can someone do me a brief descripion of how to time the ignition from the beginning all the timing marks etc etc.
Thanks.
Tony.

[Sunnysidebb]

UPDATE.

Ok. went down today and carried out a continuity test from the ECU pins out to its various end points. After a lot of messing about, found that during the engine rebuild (after the head gasket went) somehow the distributor phase sensor plug had been put onto the knock sensor and the knock sensor plug was on the distribution phase sensor, (both 2 pin plugs) However after changing these back to theyre correct plugs the car now wont start (it was running before just wont rev above 4000rpm) After talking to my mate he says that during the rebuild, the distributor was taken out, and may not be correctly put back in.
But why was it running?????
I have a couple of questions for anyone who knows about cosworth engine wiring.
Firstly. the distributor, when i take off the distributor cap, rotor arm and dust guard off, the shaft inside only has 2 lugs on it that pass the distributor phase sensor. Is this correct? if so which is the one (of the 2) triggers the coil.
It also has kent cams on it and i can not see any timing marks on them, can anyone help with this.
If the engine temp sensor (the 2 pin one that goes to the ECU) has the wires reversed will this give the wrong value to the ECU.

I think it may now just be an engine ignition timing problem, can someone do me a brief descripion of how to time the ignition from the beginning all the timing marks etc etc.
Thanks.
Tony.

Hi Tony,

Temp sensor.... No it doesn't matter its only a Resistance reading. However it should be wired as per the wiring diagram.

The Distributor phase sensor does not trigger the coil, that sensor is a fuel injector timing sensor and will not trigger the coil.

The Crank sensor is the basic trigger and speed sensor for the ecu . Timing is then added or removed to the initial pulse's to create the correct coil trigger.

Why do you think you had the 2 mixed up. I have never seen a car run with the 2 connectors mixed up. For one, the ecu wont get the 4 pulses form the crank which it has to get. The Engine can run without the phase sensor but not the other way round

You dont have to worry about the 2 lobes on the distributor shaft. So long as you have aligned the distributor up correctly the lobes will be ok.

You can check your static timing using a strobe against the TDC on the crank sensor and the pulley.You will note 4 lugs, each represents TDC for each cylinder. Dial into the strobe the correct timing for idle and the primary ( no 1)TDC mark should line up. If the distributor is out you wont be able to get the correct static timing.Lightly unclamp the distributor and slowly move until you get the correct static timing.

These engines have a set static timing so once you have reset the distributor to the initial point it requires no further adjustment.

As to setting up Camshaft timing, I hope you have a mark on the exhaust and inlet cam pulley's. I would suggest who ever put the cams in would have set up the exact cam timing and pot marked the pulley.
Cam timing is very involved and requires a DTI , a dial crank protractor, TDC indicator and a lot of time and patience and of course Kents Cams Cam timing figures. (Just for an example inlet fully open @109 deg BTDC and exhaust fully open @ 103 deg ATDC. example only)
It requires the cam cover to be removed and belt removed . Mid pint of the cam lobe found then that point has to be set up to the required degrees from / before TDC for the inlet and exhaust. A matter of 3 or 4 degrees can rob you of noticeable power.

Frank

[ossie cossie]

Why do you think you had the 2 mixed up. I have never seen a car run with the 2 connectors mixed up. For one, the ecu wont get the 4 pulses form the crank which it has to get. The Engine can run without the phase sensor but not the other way round


sunnysidebb.

The sensor wires that were mixed up were the one on the distributor. (2 pin) and the knock sensor (2 pin) Not the crank angle sensor that has white wiring, they look the same but they have different ways of getting them off the distributor one is like the the injector ones you push in a small metal clip, and the knock sensor one you have to sort of pry the locking clip with a screwdriver. i checked by looking at my engine bay wires, and tracing the wires from the ECU continuity through the 12 pin plugs, neer the coil. These have been replaced with new deutz ones.

[Sunnysidebb]

Why do you think you had the 2 mixed up. I have never seen a car run with the 2 connectors mixed up. For one, the ecu wont get the 4 pulses form the crank which it has to get. The Engine can run without the phase sensor but not the other way round


sunnysidebb.

The sensor wires that were mixed up were the one on the distributor. (2 pin) and the knock sensor (2 pin) Not the crank angle sensor that has white wiring, they look the same but they have different ways of getting them off the distributor one is like the the injector ones you push in a small metal clip, and the knock sensor one you have to sort of pry the locking clip with a screwdriver. i checked by looking at my engine bay wires, and tracing the wires from the ECU continuity through the 12 pin plugs, neer the coil. These have been replaced with new deutz ones.

That explains that, I completely missed the word Knock in your post. I have never run a knock sensor so I don’t know what effect it has if not wired correctly.
I could make a guess though and say if the ecu see's a signal from the knock sensor that it doesn’t recognise or the signal comes back in such a way it is determined to be sensing "Knocking" , then I presume it might put the ecu into limp mode or at least retard the boost and ignition and possibly stop the engine from revving . But that is pure speculation as its the only sensor I have never had fitted. Closely followed by the Lambda sensor. It was my 4x4 MSD Saph that had one. No other car I have owned has had a lambda either.


Frank

[ossie cossie]

Right, another update, took out the distributor and refitted it with the cam timing and bottom pulley timing in position. Refitted the distributor and fitted plug leads 1,3,4,2 distributor turns clockwise? viewed from the front is this correct? started the engine and it ran for a while, 15 seconds made a funny crunching noise. found that the starter motor cog cover had broke and war rolling around in the bellhousing, fitted a secondhand starter motor and tried again. now we have another problem, when we turn it over it to start, it now seems to fire before top dead centre, like the timing is too far advanced? it even when we turn off the ignition after trying to start it (sort of starts and the engine runs backerds for a couple of seconds?????? what could be wrong i am thinking that the only pulley i cant see very well is the distributor drive pulley driven by the cam belt. my next step is to remove the rad and find out if it is lined up on the timing mark. Can anyone help.