Breakdown last night - fuel or cam timing?

[1000 PR]

Car is an '85 Mk1 owned for over 15 years with only 1 previous breakdown when the headgasket went. Was running fine until 2 miles down the road heading home last night the car suddenly lost power and engine would only keep going if i kept revving it. Managed to limp to B&Q car park where called RAC out. Orange van turned up within half an hour and technician noticed car was low on petrol (although fuel light hadn't come on) so we went off to get 10 litres of fuel. Poured in but no result. Car will start but splutter and misfire and die unless keep pumping throttle. Technician checked for spark and fuel, scratched his head and concurred with me that it could be the cam timing ie. the cambelt has jumped a tooth, but couldn't tell without taking off the cam covers and didn't want to try and do this at 7pm at night in B&Q's car park so he ordered a recovery truck and bu88ered off. Recovery truck finally turned up and I got home 3 hours later than usual!

So before I take the cambelt covers off is there an easy way to check and anything else I should check first?

[mikey2]

can you check error codes at all?? if you have an afm that would be a good check to do, my mk2 did very similar when the afm went, wouldnt stay running unless the accelerator was pumped, certainly no power.

when its running, even though you have to pump the accelerator to keep it going, does it sound normal? or is it very sort of lumpy?

[mr2magic]

almost certainly AFM

[SuperRedMR2]

Mine did this once, it was horrific. I had a full tank of fuel but it stank like it was running rich.

I killed an injector, god knows how but mine behaved like yours did.

[1000 PR]

Ok thanks but UK spec Mk1's don't have an AFM but a mass air pressure sensor (MAP).

I disconnected the battery after getting it off the recovery truck on the basis it wasn't going anywhere for a while, but if I try restarting it will the error codes come back? There were no engine check lights on the dash when it broke down.

[cartledge_uk]

Ok thanks but UK spec Mk1's don't have an AFM but a mass air pressure sensor (MAP).

I disconnected the battery after getting it off the recovery truck on the basis it wasn't going anywhere for a while, but if I try restarting it will the error codes come back? There were no engine check lights on the dash when it broke down.

Try and start it again. The error code will come back.

You dont get the light on the dash, you have to bridge 2 ports in diagnostic box, then read the light flash.

check this
http://myweb.tiscali.co.uk/jimilawson/V ... Codes.html

[cabbydave1]

How long is it since you changed the fuel filter in the car could well be that

[Tiamat]

How long is it since you changed the fuel filter in the car could well be that

Rare if it is, to make it suffer like that would have to be epically blocked. Even when mine had not been changed for three years there was no problems with the fuelling.

[Boddney]

I bought a Celica once that had an empty tank, I filled it up and the very next day it did exactly what you are describing.
I changed the fuel filter and job done.
That was the first and only time I have ever changed a petrol filter, so rare indeed but a possibilty.
Moral---It can happen.

Bod

[jimi]

Ok thanks but UK spec Mk1's don't have an AFM but a mass air pressure sensor (MAP).

MAP = Manifold Absolute Pressure

[1000 PR]

Sorry - I copied that from another post as I kinew it didn't have an AFM as this is pictured in the Haynes manual but the MAF isn't.

Bridged the terminals and the error light flashed 11 times which apparently means theres a problem with the TPS or the ECU.

Personally I'm still favouring the slipped tooth as I had something similiar on another Mk1 a few years ago but who knows.

[1000 PR]

Would a slipped tooth show up as a TPS (throttle Position Sensor) error?

When I tried starting it last night to bring up the error code again, I thought for a magical 5 seconds it was going to run ok but then it lost all power and died again.

The cambelt hasn't been replaced for near on ten years but the car's only done 3000 miles and similiarly the fuel filter hasn't been replaced in this time but the RAC technician said he could feel fuel pressure so erm....

[oukie]

Mine did something similar

On my first mk1 the king lead (HT) failed and would only only worked if I booted it, as in if I let the revs drop I would lose all power and she would cut out , just as you are describing,


Chris

[dopiaza]

Check the pipe from the manifold to the MAP sensor - mine cracked and did exactly this. Local garage said he'd seen it a few times and replaced the metal pipe with a plastic one - problem fixed.

Graham

[1000 PR]

Ok thanks. Swapped all the leads over at the weekend but made no difference. Car started for about 3 seconds then died again. Checked TPS and all settings were within range. So have ordered a new fuel filter from Camskill today but will look at manifold to MAP sensor pipe this evening (in the dark unfortunately) and report thanks.

[tottacrolla]

if the cambelt has jumped a tooth (unlikely) then the ignition timing could be out as the ignition timing is set from the exhaust cam.
I would be looking at the distributor cap and rotor arm.
Code 11... tps
It could be that the ignition timing is not advancing if the tps is not coming out of its 'idle' map mode.
Do you have a timing light ?

[JMR_AW11]

This is from memory (so could be wrong) but I thought that code 11 can be generated on a healthy car if you press the throttle whilst you are looking for codes with the wire link fitted in the check connector.

Try clearing the codes and next time don't touch the throttle during the time you read the codes.

If you still get code 11 then there might be something wrong with the IDL switch on the throttle.

I think the code 11 test applies during the code reading session and it checks that the IDL switch is closed with a closed throttle. So if you press the throttle during the code reading you get a fail... Can anyone confirm?

I doubt code 11 will be related to your current fault though as the car would still run OK (you would get poor idle performance if the IDL switch failed but this doesn't fit your symptoms)

I suppose the car would run bad if it got stuck with the IDL switch always closed but this is pretty unlikely to be your problem as the fuel would cut at a certain rpm eg less than 2000rpm and the engine would die at the same rpm point and come back to life at a lower rpm (like a kangaroo but there would be no misfire, just on or off).

[tottacrolla]

JMR is correct, code 11 is a check code I think. If you depress the throttle when checking codes you should see code 11 release the throttle and it should not show code 11.

[1000 PR]

I tried starting the car (and pressed the throttle) but as it died again I switched off the ignition, before I placed the jumper wire in the diagnostic port and then turned the ignition back on to read the codes, so this doesn't make sense.

And no sign of any cracking on the metal pipe to the sensor either.

Oooer. . .

[Tiamat]

I am probably going to be down Southampton way next week, am happy to lend my limited expertise.