Shuddering in Overdrive - not coils, but fuel injectors?
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Shuddering in Overdrive - not coils, but fuel injectors?
Hello,
I've recently been reading about several threads that mentioned shuddering from the engine when the torque convertor locks up, and is easily mistaken as a transmission problem. Luckily for me, I read this the night before it happened to me, and figured that the same thing was happening to me - ignition coil(*) going bad.
Well, I'm 100 miles from home, and nothing to do except pop the hood the reseat all the plug wires - of course this doesn't help. I go another few miles with the OD shudder, then pull over and reseat all of the electrical connectors on the fuel injectors. Now it'* shudder free!
The same situation happened about a year and a half ago when I purchased the car, though it would shudder at any speed, in any gear, and it turned out merely to be loose fuel injector connectors. But yesterday, it showed the exact symptoms of coil failure: runs fine in lower gears, then starts acting up only when the TCC locks up. But after reseating the FI connectors, it was absolutely fine for 100 miles. A weak coil I can understand missing under load, but an intermittant FI should miss any time at all, right?
Can anybody give a plausible mechanical explanation for this?
I've recently been reading about several threads that mentioned shuddering from the engine when the torque convertor locks up, and is easily mistaken as a transmission problem. Luckily for me, I read this the night before it happened to me, and figured that the same thing was happening to me - ignition coil(*) going bad.
Well, I'm 100 miles from home, and nothing to do except pop the hood the reseat all the plug wires - of course this doesn't help. I go another few miles with the OD shudder, then pull over and reseat all of the electrical connectors on the fuel injectors. Now it'* shudder free!
The same situation happened about a year and a half ago when I purchased the car, though it would shudder at any speed, in any gear, and it turned out merely to be loose fuel injector connectors. But yesterday, it showed the exact symptoms of coil failure: runs fine in lower gears, then starts acting up only when the TCC locks up. But after reseating the FI connectors, it was absolutely fine for 100 miles. A weak coil I can understand missing under load, but an intermittant FI should miss any time at all, right?
Can anybody give a plausible mechanical explanation for this?
#2
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Re: Shuddering in Overdrive - not coils, but fuel injectors?
Originally Posted by StoopidSavant
Can anybody give a plausible mechanical explanation for this?
1) When OD first engages, increased engine load requires a slightly richer charge in the cylinders, and the intermittently-firing injectors can't keep up with the demand
2) When OD first engages, the engine shifts in its mounts slightly due to powertrain stresses, and disturbs the loose wiring harness to the injectors
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