Re: 4 cyl (2200) engine hesitates when warm, fine when cold 1994 camry, 104,000 mi

Can you describe the "hesitation" you were experiencing? My 92 Camry has what I describe as sort of a hiccup. It's not verry consistant, but it does seem to happen after the car is warmed up and out of the cold start high idle mode. Basically, it will just be idling along, then it like wants to die real quick and then it revs itself a bit and idles fine and then does it again. Some times it's a few back to back other times, a few minutes in between. Also, when driving, occassionally when I accelerate, it bogs down bad until I left off the gas. Is this the sorta problem you were having? I swear I just replaced the damn distributor about 20,000 miles ago. Aren't those things supposed to last longer than that? Is this an inherent problem with Camrys?

So I trouble shot just about everything except a new distributor, > ignitor and ECM. Brought the car to the Toyota dealer with a list of > what I had done, no suggestions, didn't want to step on any toes etc. > (It was bad enough telling them the 20 or so tests that I had done.) > After two days they called said that they had duplicated the problem > swapped the distributor from a car on the lot going to a reseller, and > "fixed it" They will put in a new Toyota distributor, and want $700 > plus tax for the whole deal. I know I can put in a after market > distributor for $130, but they have already put in 3.5 hours (times > $80/hour, ouch) plus the cost of the distributor. So as I read the > board I'm surprised on how many distributors have to be changed. What > is going on? Is it time for a class action suit or is it just because > so many Camry's have been sold that the numbers are so high? To me > clearly something is not designed right--Well, I hope this fixes it. > Another distributor problem searchable by google. > > > > The distributer cap and rotor were only $18, nothing much, I've got a > > > real heat gun today and will try that on the internal coil to see if > > > the resistance goes up/goes down. As I mentioned to somebody else the > > > plug wires go from about 9k upto 22 kohms depending on length, I guess > > > I could play the heat gun along these dudes to see if one fails > > > (carefully). The ignitor I want to stay away from as it is about 3 > > > bills until a last resort. What does the ignitor do? > > > > > > Ignitors are a hardy (usually) little device. Basically they accept

input

> from the pulse generator which consists (usually again) of a 4 pointed

star

> shaped magnet and a pickup coil. All this eis located in the distributor
.
> As each point passes a small pick-up coil (the distance between the star > > point and the p/up coil pole-face is critical and is supplied in the

manual)

> an electrical pulse is generated. On Fords these are quite large (in the > > vicinity of a volt) due to a different design ie multi pointed star

passing

> many coils each engine cylinder power cycle. This sig-pulse is in time

with

> each cyl reaching top-dead-centre/compression-stroke, give or take a few > > degrees of arc (this is adjusted to effect base-idle advance). The

igniter

> receives these pulses and amplifies them to trigger the > > output -switching -power transistor which causes a burst of current to

flow

> in the coil. Timing is effected by passing the sig-pulses through the

EMC,

> which in turn delays the pulse by an amount to give correct advance.

Some

> configs are designed to maintain saturation current in the coil until

the

> power transistor (sometimes referred to as 'the switching element') is > > switched off for a brief time (in the millisecs) causing field collapse

in

> the coil and thus spark. Other designs have no between cyl saturation > > current, relying instead on the rising field in the coil caused by the > > switch on time of the power transistor. > > > > Thesethings usually either work or dont work, but it maybe the case it

is

> running at reduced performance. Also some igniters will not operate when > > battery supply to them, drops below 10v. This often caused by resistance

in

> loom connectors carrying the supply to the igniter. > > > > Jason > > > > > > > > > > I don't have any > > > test info for it anywhere. Does it shape the spark based on the ECU? I > > > could put a scope on it's output power transistor, which is also be > > > the input to the primary on the internal coil lead. I'm guessing that > > > the primary should be getting something like 25 pulses/sec at idle > > > 770RPM / 2 (for a four cycle) * 4 (cyclinders) /60 sec/min =25.667 hz. > > > ...grant
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Dan Bassett
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