Hi every body, I wander if anybody has any idea'st could be wrong with my 1983 308 QV It has developed a misfire and has lost power mainly under 3500 rpm from 3500 upwards it seens to improve?? Also the Catalytic converters/exhaust is getting so hot that even after driving just a short distance 2/3 miles the SLOW DOWN LIGHTS are coming on.First flashing and then staying on,could it be that the car is just running 6/7 cylinders hence the noticable miss on lower rpm and that the unburnt gas in the other cylinders is heating up the cats???.I have not yet had a chance to test the spark on all cylinders but I thought someone may have some idea's.I can not understand why the catrs are getting so hot in such on such a short drive.Thanks everybody Mike308QV PS. this site fantastic.
If you're not firing on all cylinders, some raw fuel is likely working its way into your cat, making for greater heat and possibly setting off the slow-down light. Re: the miss, carefully inspect each of the plugs to try to dtermine which cylinder(s) aren't firing properly. Also, carfully inspect the extenders for holes/cracks/etc--as this is common. It's happened to me 3 times in the last 3 years. If they're OK, check all of the usual suspects next--ie wires, digiplex connectors, sensors, etc. If you find that an extender has burnt through, also replace the plug it was attached to as it may have glazed and won't fire again, even with a new proper connection/extender.
Hi Doc, What are digiplex connectors and what sensors are you referring to.Also I forgot to mention that the idle fluctuates up and down,and there is a tick sound coming from the drivers side of the engine but it does not sound like a valve/tappet and also it seems to stop at higher rpm.
I'd bet, based upon what you're saying , is that the tick sound is a spark arcing somwhere. As I mentioned, check the extenders closely for burn holes. Also, if you run the car in a very dark place, you may even see the spark arcing. The arcing, if that's what it is, could be coming from a split ignition wire or poor connection of such as well. Re: connectors to clean/check, the Digiplex bulk head connectors to the engine are located near the driver's side wheel well, right next to the oil cooler. You'll see 2 connectors. Disconnect them and spray electrical contact cleaner into all of the connection surfaces. The Digiplex units themselves are located in the far left side of the trunk under a floor cover. It's good to check those connections as well and to be sure the ground wire in there is good and tight ( I found my to be loose last year). Some guys. have secured the digiplex connectors vis large tie-wraps as they can sometimes work loose. Also, check the coil wire connections. If you don't find anything wrong here, remove the distr caps, reconnect all of the ignition wires, and clean all of the rotor connection areas. HOWEVER, I'd bet anything that that clicking sound is a grounded spark . Replace the wire or extender/plug and you'll probably be good to go. If you see the spark coming from an ignition wire, consider replacing all of them, as they may be breaking down w age.
I have checked all the connections/extenders etc and found two problems now fixed.The car was running great with no missing,but after driving it for 2/3 miles the slow down lights came on again.It also then lost power and started to miss again.Are the slow down warning lights connected to any saftey devise to make the engine miss and loss power to make you slow down??The engine temp remained normal all the time also the oil temp and presure great. What can be making the CATS GET SO HOT in such a short time at normal driving speeds.And hopefully if I can cure that it will stop the loss of power??
There's no "intelligent" connection on your K-Jet with Lambda system between the warning light system and the ignition/injection system -- so even if the warning light is mis-behaving, when you lose power you definitely have a real problem elesewhere (almost certainly ignition). So it's probalby the other way around -- when you cure the power loss, you will not have the warning lights coming on. The reason the cat heats up so quickly is that when you lose the ignition on one bank all that fuel is ignited inside the cat (a small metal box with no cooling system) -- even when they are working "correctly" they are little toasters.
