Poor/non start and a cold misfire/hesitation
Poor/non start and a cold misfire/hesitation was created by TaffMGF
Posted 1 year 10 months ago #200899
Hello all and a HNY to you all.
My '96 VVC has started to play up. It can be extremely reluctant to start, to the point of turning over until the starter solenoid starts clicking. When it does start, there is usually a misfire and hesitancy/flat-spot until the engine is up to working temperature.
I have had this once before; the battery went flat so i called out recovery. He hooked it up via jump leads to his truck and almost forced it into life. He suggested the fuel filter, which i changed the following weekend (that would have been 6 months ago).
The car has been outside all over the festive period, under a tarp, and this does have the feel of a weather-related issue. It started fine the other day when it was sunny and then 24 hours later in a downpour, it wouldn't start at all.
Searches and google don't seem to point to a single issue, it could be something prosaic as plugs, an inlet manifold gasket or even as simple as a pipe off the manifold pressure sensor.
I will push the car into the workshop at the weekend, but in the meantime, any hints of were to have a look?
Thanks, Taff
My '96 VVC has started to play up. It can be extremely reluctant to start, to the point of turning over until the starter solenoid starts clicking. When it does start, there is usually a misfire and hesitancy/flat-spot until the engine is up to working temperature.
I have had this once before; the battery went flat so i called out recovery. He hooked it up via jump leads to his truck and almost forced it into life. He suggested the fuel filter, which i changed the following weekend (that would have been 6 months ago).
The car has been outside all over the festive period, under a tarp, and this does have the feel of a weather-related issue. It started fine the other day when it was sunny and then 24 hours later in a downpour, it wouldn't start at all.
Searches and google don't seem to point to a single issue, it could be something prosaic as plugs, an inlet manifold gasket or even as simple as a pipe off the manifold pressure sensor.
I will push the car into the workshop at the weekend, but in the meantime, any hints of were to have a look?
Thanks, Taff
by TaffMGF
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Replied by Cobber on topic Poor/non start and a cold misfire/hesitation
Posted 1 year 10 months ago #200901
Yeah do all the usual suspects, check the plugs, in particular check the gaps, sometimes when something is reluctant to start when cold/wet closing the plug gaps by a bee’s dick can get ‘em going…….. usually means the ignition system is not up to par and needs a thorough going over.
Plug leads could be breaking down with too much resistance and crossfiring.
As it seems to be temp related, check the temp senders, there are two, one for the gauge and the other talks to the ECU. If it’s telling porkies to the ECU, then of course it’ll be running like a hairy goat. Don’t worry about the gauge sender it won’t be effecting the running.
Don’t ever rightoff the possibility of the fuel pump shitting itself on an intermittent basis, had two do this to me…..bloody hard to diagnose as the bastard of a thing would come good whenever you had tools handy.
You might have a shitty fuel pump relay, or even crap electrical connections on the fuel circuit, retracting and expending with temperature variations.
O2 sensors can play havoc with ECUs when they’re telling lies like a candidate on election day
Once you done with that lot, get back to us.
Plug leads could be breaking down with too much resistance and crossfiring.
As it seems to be temp related, check the temp senders, there are two, one for the gauge and the other talks to the ECU. If it’s telling porkies to the ECU, then of course it’ll be running like a hairy goat. Don’t worry about the gauge sender it won’t be effecting the running.
Don’t ever rightoff the possibility of the fuel pump shitting itself on an intermittent basis, had two do this to me…..bloody hard to diagnose as the bastard of a thing would come good whenever you had tools handy.
You might have a shitty fuel pump relay, or even crap electrical connections on the fuel circuit, retracting and expending with temperature variations.
O2 sensors can play havoc with ECUs when they’re telling lies like a candidate on election day
Once you done with that lot, get back to us.
"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"
Last Edit:1 year 10 months ago
by Cobber
Last edit: 1 year 10 months ago by Cobber.
The following user(s) said Thank You: TaffMGF
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Replied by SteveFMk1 on topic Poor/non start and a cold misfire/hesitation
Posted 1 year 10 months ago #200904
One other check while your checking everything Cobber suggested is the hose that goes to the ecu, if you have an air leak that could give the ecu the wrong info on engine temp.
by SteveFMk1
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Replied by Airportable on topic Poor/non start and a cold misfire/hesitation
Posted 1 year 10 months ago #200906
Cold damp conditions = condensation, which = tracking. With the low current signals on which all “modern” cars depend, an important signal may find a route through the dampness to ground rather than its intended target & it only needs one track & you can have a problem. Multiply that by the number of contacts on the ECU & you get a glimpse of the possibilities. A good & fully charged battery, it goes without saying is an imperative.
Cranking the engine over in the hope of it starting could easily fill the silencer & catalytic converter with unburned fuel, which if the car were to fire could go bang. Which ever way up your cat will not be your best friend.
Cranking the engine over in the hope of it starting could easily fill the silencer & catalytic converter with unburned fuel, which if the car were to fire could go bang. Which ever way up your cat will not be your best friend.
by Airportable
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