18 months in,,,, and first break down!!
Discussion
Yep,after owning my Griff for a year and a half,she decided today to leave me stranded by the side of the road!... now i managed to get it going again,but need some advice from those in the know,to try and pinpoint the problem.
Car is a 95 with 72k showing,has been ultra reliable since ive had her when running,up until the last six months,when intermittantly,when hot it would hesitate something cronic after a gearchange,not always,in fact pretty random,but when revving the car to about 4k and above,and then changing up,there would be about 2-3 seconds before the engine would chime back in,i thought it was the inlet hose collapsing,or similar,but as its so random i now think not,anyway it did it again today,but then the engine started to miss pretty bad,revs would be all over the place at idle too,anywhere between 1500-2000 rpm,and would not drop back down when the car came to a stop as normal,running got progressivly worse,at junctions i had to keep the revs up to prevent stalling,it then ran normally again for about 15 mins,and then started to run rough again,so something is breaking down but not all the time it would seem..then the inevitable happened,she cut out and would not restart,tried several times,but wouldnt have it,bonnet up had a look,could not see anything obvious,checked ht lead from coil to cap,checked cap security,low tension side connections to coil etc,still would not start,pretty sure the fuel pump was primimg,but with the roof off (it is a griff) it was hard to be sure with all the traffic about,tried to start again,still nothing,i delved into the passenger footwell and all i could think of was to swap the two silver relays around as i think thats been mentioned on here before,again tried to start and after about 3 seconds cranking it fired up,but this was not a complete cure,as although it ran,it was rough,missing and very fluffy on throttle responce,nursed it home, again it ran fine at times,back in the garage,again the idle speed was high and disconecting the stepper made no difference...... car has had a recent full service,though it had the initial hesitance before that,have a new cap and rotor to stick on but dont think thats the cause as its intermittant,leads are less than 2k old,plug extensions were recently checked and measured at 5k ohms,so again not them.... so any pointers? coil maybe? what else do i need to check?
Thanks in advance
Car is a 95 with 72k showing,has been ultra reliable since ive had her when running,up until the last six months,when intermittantly,when hot it would hesitate something cronic after a gearchange,not always,in fact pretty random,but when revving the car to about 4k and above,and then changing up,there would be about 2-3 seconds before the engine would chime back in,i thought it was the inlet hose collapsing,or similar,but as its so random i now think not,anyway it did it again today,but then the engine started to miss pretty bad,revs would be all over the place at idle too,anywhere between 1500-2000 rpm,and would not drop back down when the car came to a stop as normal,running got progressivly worse,at junctions i had to keep the revs up to prevent stalling,it then ran normally again for about 15 mins,and then started to run rough again,so something is breaking down but not all the time it would seem..then the inevitable happened,she cut out and would not restart,tried several times,but wouldnt have it,bonnet up had a look,could not see anything obvious,checked ht lead from coil to cap,checked cap security,low tension side connections to coil etc,still would not start,pretty sure the fuel pump was primimg,but with the roof off (it is a griff) it was hard to be sure with all the traffic about,tried to start again,still nothing,i delved into the passenger footwell and all i could think of was to swap the two silver relays around as i think thats been mentioned on here before,again tried to start and after about 3 seconds cranking it fired up,but this was not a complete cure,as although it ran,it was rough,missing and very fluffy on throttle responce,nursed it home, again it ran fine at times,back in the garage,again the idle speed was high and disconecting the stepper made no difference...... car has had a recent full service,though it had the initial hesitance before that,have a new cap and rotor to stick on but dont think thats the cause as its intermittant,leads are less than 2k old,plug extensions were recently checked and measured at 5k ohms,so again not them.... so any pointers? coil maybe? what else do i need to check?
Thanks in advance
Go about it logically- The HT system is pretty simple, and you can do an easy test to check the coil and amp. Take the distribitor cap off, and remove the king lead. Attach it by whatever means to a plug. Then rotate the engine until one of the trigger lobes lines up with the pickup in the distributor. Now turn on the ignition,( Dont start!) and tap a screwdriver tip across the air gap between the rotor and pickup, and you should get a good spark, as the magnetic circuit is completed. Its worth borrowing a rotor arm and trying another one as well, but the symptons are too bad to be plug leads or caps. Id also check the AFM. Try disconnecting it and see if the symptoms change, and heres a really good bit Mark Adams did on testing them:
Here's a quick fault finding guide.
Note that you can drive without an airflow meter in case of emergency (i.e. airflow meter disconnected), because the system will drop into a default (limp-home) mode based on throttle opening.
Most airflow meter faults will cause the engine to run excessively rich. However if the airflow meter remains connected whilst defective then the vehicle will probably not run. In most cases the output from a defective airflow meter will be in the range 2.0-2.5 Volts, which is a viable value. This represents a moderate load and will cause heavy over-fuelling without setting a fault code.
Testing is performed in the following manner. Peel back the rubber boot on the airflow meter connector and leave it plugged in to the airflow meter. Set up the digital multimeter to read voltage. Insert the negative probe into the Red/Black wire (sensor ground), and the positive into the Blue/Green wire (Airflow signal).
Turn on the ignition, but do not start the engine. The meter should immediately indicate a reading of approximately 0.3-0.34 Volts. Most defective airflow meters will overshoot to 0.8 Volts or higher, and take at least 2 seconds to come down to the correct voltage.
Now start the engine, and the reading should rise to 1.6 Volts (3.5 Litre engine) to 1.75 Volts (5.0 Litre engine).
The next test is full load, and as with the fuel pressure test it will require use of a rolling road or a steep hill in the same manner. Under full load the voltage should rise to 4.45 Volts (3.5 Litre engine) to 4.95 Volts (5.0 Litre engine).
On this injection system, the idle CO mixture adjuster is provided on the airflow meter. It is located in a boss on the top of the airflow meter, pointing towards the engine. Leaving the multimeter negative probe in the Red/Black wire, move the positive probe to the Blue/Red wire.
Now turn on the ignition but do not start the engine. Observe the voltage. The normal adjustment range is between 0.0 and 3.6 Volts, with the higher Voltages producing higher idle CO values. There are approximately 20 turns of the adjuster screw to cover the entire range.
Annoyingly, the adjustment may be clockwise or anticlockwise to increase the value, and this varies from meter to meter! For this reason it is always preferable to have the multimeter connected in this manner when adjusting idle CO, so that you see can something is actually happening.
Typical Voltages that would be found at this point are between 0.9 to 1.4 Volts for non-catalyst cars. This Voltage is always factory pre-set to 1.8 Volts for catalyst vehicles. A value near to 3.5 Volts will generally produce an idle CO value of 9-10%. These Voltages may be used as safe initial values particularly if no CO measuring equipment is available.
Apart from that an ECU fault code reader is a good place to start before you swap too expensive many bits.
Here's a quick fault finding guide.
Note that you can drive without an airflow meter in case of emergency (i.e. airflow meter disconnected), because the system will drop into a default (limp-home) mode based on throttle opening.
Most airflow meter faults will cause the engine to run excessively rich. However if the airflow meter remains connected whilst defective then the vehicle will probably not run. In most cases the output from a defective airflow meter will be in the range 2.0-2.5 Volts, which is a viable value. This represents a moderate load and will cause heavy over-fuelling without setting a fault code.
Testing is performed in the following manner. Peel back the rubber boot on the airflow meter connector and leave it plugged in to the airflow meter. Set up the digital multimeter to read voltage. Insert the negative probe into the Red/Black wire (sensor ground), and the positive into the Blue/Green wire (Airflow signal).
Turn on the ignition, but do not start the engine. The meter should immediately indicate a reading of approximately 0.3-0.34 Volts. Most defective airflow meters will overshoot to 0.8 Volts or higher, and take at least 2 seconds to come down to the correct voltage.
Now start the engine, and the reading should rise to 1.6 Volts (3.5 Litre engine) to 1.75 Volts (5.0 Litre engine).
The next test is full load, and as with the fuel pressure test it will require use of a rolling road or a steep hill in the same manner. Under full load the voltage should rise to 4.45 Volts (3.5 Litre engine) to 4.95 Volts (5.0 Litre engine).
On this injection system, the idle CO mixture adjuster is provided on the airflow meter. It is located in a boss on the top of the airflow meter, pointing towards the engine. Leaving the multimeter negative probe in the Red/Black wire, move the positive probe to the Blue/Red wire.
Now turn on the ignition but do not start the engine. Observe the voltage. The normal adjustment range is between 0.0 and 3.6 Volts, with the higher Voltages producing higher idle CO values. There are approximately 20 turns of the adjuster screw to cover the entire range.
Annoyingly, the adjustment may be clockwise or anticlockwise to increase the value, and this varies from meter to meter! For this reason it is always preferable to have the multimeter connected in this manner when adjusting idle CO, so that you see can something is actually happening.
Typical Voltages that would be found at this point are between 0.9 to 1.4 Volts for non-catalyst cars. This Voltage is always factory pre-set to 1.8 Volts for catalyst vehicles. A value near to 3.5 Volts will generally produce an idle CO value of 9-10%. These Voltages may be used as safe initial values particularly if no CO measuring equipment is available.
Apart from that an ECU fault code reader is a good place to start before you swap too expensive many bits.
Thanks for the info,but the symptoms seem to me heat related,i think the car finally started due to the fault cooling down....would the afm be affected by heat,and then revert back to normal running/then fail/then normal?...thought once they were goosed that was it? i also think the high idle is associated with the problem,as that occurs when the car starts to run rough,and then thought the fi was trying to compensate for the problem by raising the idle speed?,the miss/hesitation when changing gear feels very electrical though,i have a cap and rotor anyway,so no cost there to fit and see,but always glad for advise.
The symptoms you describe are not uncommon for cars your age.
Go here:
http://www.rv8r.co.uk/uneven%20running.html
for some easily performed checks.
My car suffered a similar problem and it turned out to be the connections, the 40-pin plug, on the ECU. A little contact cream and it was just as if I'd had the car tuned. It's a 10-minute job.
Go here:
http://www.rv8r.co.uk/uneven%20running.html
for some easily performed checks.
My car suffered a similar problem and it turned out to be the connections, the 40-pin plug, on the ECU. A little contact cream and it was just as if I'd had the car tuned. It's a 10-minute job.
Ballistic Banana said:
Doesnnt a dodgy 100amp fuse conection cause these probs iirc!! Also ignition amp as well. Would look at these along with what blitz has suggested( which is a very good guide might I add
)
BB
I agree,Blitz advice is well receieved and i would not discount it out of hand at all,he after all knows far more about these things than i will ever know,and i would not discount his post.... btw the amp was replaced a few months ago along with the fi temp sensor due to a poor cold start issue,not touched the car today,i guess when i have a day off tomorrow it will run absolutly fine from the moment i start it..... i will add checking the 100 amp fuse to the list of things to check..... many thanks )BB
Right,good news and bad news...... good news is ive been out for about 3 hours in the car,and its ran perfect,not a hiccup,miss stutter nothing.... bad news is im not sure what the actual fault was,or even if i have actually cured it.... replaced the cap and rotor that i had spare,brand new lucas items the pair,checked every connection i could,ecu plug,underbonnet plugs afm,lambda's etc,fuel pump connections,even the 100 amp fuse,couldnt really see anything wrong as i went,i did though replace the HT king lead for a shorter version,the one i had was a bit long being a landy item,and was sitting on top of the alternator,so not sure if it was picking up interferance or not,anyway its now routed well away....one other thing,whilst i had the ecu out of the car,i noticed some numbers and initials written in black ink on the label,5.0 for the engine size obviously,but also 1719 and what appears to be the initials MH.... any ideas what thats about?
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