Morning all, new here and hoping that someone can help with a new issue!!
A couple of weeks ago the distributor cap and rotor arm were replaced and this was all good for about 100 miles when a misfire developed, so pulled the cap and arm again and no sign of an issue but replaced with the old cap and rotor arm, still have a misfire.
Even with the misfire the car would start on the first or second compression.
Put a Colour Tune on each cylinder and found that No:5 was running rich (yellow and uneven flame, never any hint of blue and different to all other cylinders), so I changed out the injector with one in the garage. This has got all cylinders running more or less evenly and when on the road itâs smooth with plenty of power.
The issue now is that it will not start without a significant amount of throttle opening and will crank for a significant time before starting.
There is plenty of information online and in the manuals about a complete non-start, but once started it is spot on so most of the checks are negated. Has anyone seen anything like this before or have any ideas what I can try to get it sorted out?
Matt, perhaps the cold start capability has been AWOL for some time, but an over-rich dribbling no 5 covered up for it somehow?
The guys here will take you through the trouble-shooting process, but âfeet-offâ starts are the norm. So allowing more air in by giving it some throttle is likely making it a weaker mixture and therefore worse cold starting (unlike a carb engine with accelerator enrichment mechanism?
Matt,
Welcome!
Check that your Cold Start Injector and Extra Air Valve (also called the Auxiliary Air Valve) are working properly and that your throttle butterfly is properly gapped to 0.002 inches.
Matt, in additional to the apropos suggestions youâve received so far, check the ducting between the throttle body and the Air Flow Meter. Leaks here can create some odd engine behavior.
Does the starting problem change is engine temperature?
Another thing to check (if the ducting is air tight and idle speed is right plus if it also affects hot starts) is the coil. I had a hard time going through it all, including a new cheap ebay coil, and in the end a new coil from a donor engine fixed the bad starting behavior (hot and cold). The engine ran fine once it got going. Maybe a degrading connection?
David
Under fueled, Doug. Not had first cuppa, when posted.
In USA versioned carb cars, a cold start is best done as follows. Stomp the throttle pedal once in moderate weather, twice in cold. Remove foot. Crank. Almost always gets a start. Pedal down adds more air, leaner mix hard to fire in the cold.
Some early carbs had a summer and winter setting for the pump arm.
Now, my primitive carbâd T Ford. Winter start.
jack up the right rear wheel. Inherent clutch drag minimized. Twist choke rod one turn rich. Set choke closed. Ignition off. hand crank one turn minimum. Full retard spark lever. Throttle lever at 3/4⊠Crank handle at 6:00 ,
Fingers and thumb on same side of the handle. Pull up sharply. A healthy engine will start. if not so much, push it down hill, jump in and engage the clutch and hope!!!
If it does, push it off the jack and jump inas it goes by!!!
**
As Peter says, Matt; the engine is a âfeet offâ starter - you touch the pedal at your peril while crankingâŠ
As Doug implies; is this difficulty only with the engine old or only while hot - a useful clue. If both, and anyway; check AFM to throttle body for leaks/damage or loose clamps.
Remove the air hose on top of the AFM and look at the slide. It should be half open when cold, and closed with the engine hot. If malfunctioning it will interfere with hot or cold starting - depending on slide position. And for the record, what is your cold and hot idle - a good clueâŠ
That the Colour Tune showed normal fuelling, and the engine otherwise runs normally after starting, this is a starting problem - with limited suspectsâŠ
Frank,
I am sure that you did not mean âAFMâ but âAAVâ or âEAVâ for the Auxiliary Air Valve or Extra Air Valve as Jaguar used both names for that component.
Sorry for my slow response, apparently putting up the new kitchen lights is more important - says OCHC!!
Iâm thinking that Peter might be right about the cold start system, from what Iâm reading it looks as though it works every time the engine is started and not just with a cold engine, as I thought it did.
So thatâs the next thing to investigate when I have a few minutes, will report back.
