95 Camry Ignition problem hard to start

I think you're digging down much, much further than you have to.

Ever since the dawn of Toyota (in the US, at least) there is an issue with older cars that won't start esp when warm. The contacts on the starter wear down. For some reason, they will start the car just fine cold, but when the car warms up they like to hesitate.

IIRC, there is a cover over the soleniod you can remove and check the condition of the contacts. They used to be a few bucks from a Toy dealer, but $17 seems to stick in my head right now.

THis would be the first place I would look on a Toy that starts hard when warm...

Mark wrote in news:6a00f53c-eeec-4816-a995- snipped-for-privacy@w19g2000yqa.googlegroups.com:

Can you /precisely/ describe the /actual behavior/ of the engine/starter when you turn the key and the engine does not start?

You can try the Yahoo group I help moderate: Toyotas_Only. We have a number of actual Toyota techs.

Yeah is the engine cranking normally just not firing, or is the starter dragging while trying to start the motor??

the starter / engine cranks just fine....it's not the starter..

FYI you are correct about the starter contacts, I had that problem 6 months ago and replaced them,,, this is a different problem, the engine cranks, there is fuel and spark but the spark appears to be late...

it will usually catch after several seconds of cranking but it used to start immedialy, now it needs to crank for a while and I can see the spark is late due due the iGT pulse being wide...

thanks

Mark

Mark wrote in news: snipped-for-privacy@a11g2000pro.googlegroups.com:

when is the last time you put in a fuel filter? I see this a lot on all makes when the filter is half plugged and the innitial fuel pump shot will not pressurize the system enough. KB

I had a 2.8 Celebrity that bogged when entering the x-way. Fuel filter fixed that. Couple years later it started cranking more to start. Like the OP's. Went from instant on to 3 or 4 seconds of cranking over a period of a year or so. Longer when it was hot. Then one day it wouldn't restart when hot. I had picked up fried chicken, so we jumped on a bus to get home. Had my wife drop me off at the car when we went to work in the AM. Started right up with the now usual 3-4 seconds of cranking. Drove it to my mech with no issues. He couldn't believe I drove it in when he found the fuel pump pressure was 2.5 psi. New pump fixed that. Go figure.

--Vic

If you want to check the timing then check the timing. I don't think you can draw any mmeaningful conclusions about timing from looking at how long a period the coil is energized unless you have established a reference base first.

-jim

In message , Mark writes

Surely the width of the pulse in direct related to the cranking speed, so the slower the speed, the larger the dwell angle.

Clive wrote in news:2B $ snipped-for-privacy@yewbank.demon.co.uk:

That's counter-intuitive, actually.

The coil needs a certain number of milliseconds to saturate. That number of milliseconds is constant, regardless of engine speed. One drawback of the old points-and-condenser system was that actual coil-charge time varied with engine RPM (shorter at high-rpm). Modern electronic systems do not have this issue.

Doesn't really matter if the system is electronic or mechanical you still have the same limiting condition that there is only so much time for switching between cylinders. If you want to extend the time to get complete coil saturation at high RPM you need multiple coils instead of one coil for all the cylinders.

-jim

nds of cranking but it used to

Clive,

yes I am starting to think you are correct...

At cranking speed the RPM is very low and the pulse widths (dwell) and rep rate all seem to get longer and shorter proportionaly with RPM. Above a certain RPM around 1500 the dwell time seems to be fixed and no longer gets shorter as the RPM increases. I am starting to think this is totally normal and has nothing to do with the problem. The car seems to be fine now, running and starting so I will wait and see. I was able to scope the Ne and G pulses out of the distributor pickups while cranking (with them disconnected from the ECM and connected to my scope so the car did not start of course) and they looked normal.

So right now the problem could be anything and I will have to wait for it to happen again.

Mark

 I was able to scope the Ne and G pulses out of the

Were you able to scope them with the ecm connected? If you did all your scoping with the ecm disconnected... the ecm may tighten up the signal during cranking... Either way, there is some excellent factory toyota stuff here:

that may be of use to you. Have you looked at iant.net? Much better source of the kind of hardcore tech you may need. HTH, Ben

Mark wrote in news: snipped-for-privacy@o7g2000prn.googlegroups.com:

A couple of suggestions:

1) Have you checked the voltage though the primary feed to the coil while cranking? Do you see 6V? 8V? 12V? Other?

2) have you actually LOOKED at the spark being produced while cranking? By that I mean: pulling a plug wire, sticking a spare plug into it, holding the plug body to a handy ground, and operating the starter. In a dark garage, or at night, the spark--even when cranking--ought to be very snappy and purply-blue.

problem #1 solved, the IAC was stuck, I cleaned that out and idle is now good most of the time.

But I'm pretty sure one of the ignition sensor pickup coils inside the distributor is intermittent, (I'm not taking about the HV ignition coil, I'm talking about the low level reluctor wheel pickup coils). They are known to get flaky with temperature swings, I want to be able to trust this car, so at this point I need to replace these.

Problem is I can't seem to find them for sale anywhere.

I know I have the option to buy a distributor, but I just need the pickup coils.

Any sugestions.

thanks

Mark

Mark wrote in news:8ee538e3-a690-437e-b562- snipped-for-privacy@a28g2000prb.googlegroups.com:

1) Have you checked the voltage though the primary feed to the coil while cranking? Do you see 6V? 8V? 12V? Other? 2) have you actually LOOKED at the spark being produced while cranking? By that I mean: pulling a plug wire, sticking a spare plug into it, holding the plug body to a handy ground, and operating the starter. In a dark garage, or at night, the spark--even when cranking--ought to be very snappy and purply-blue.

OK, Car seems to run without hicupp if I connect the E1 TE1 test points so it is in base timing mode. Its hard to start but it will run without intermittent.

Also I put it in ECM test mode where is sets codes without delay. It set a code 31 twice in that mode, which is MAP sensor. I monitored the signal voltage out of the MAP sensor and it is appears perfect, I was watching it on a scope even while the car stalled.

When it cranks and won't start, there is spark, and it tries to start but backfires, I think this fit with an intermittent timing problem.

When its running, it runs perfectly, so the base timing is good, something seems to happen in the ECM or one of the sensors to throw off the timing. The MAP sensor can do that but the voltage look correct.

Questions: Does the ECM ignore the MAP sensor when the ECM is in base timing mode with TE1 jumpered to E1?

I'm suspecting an intermittent problem with MAP wiring to the ECM or the MAP circuit in the ECM.

To Tegger, I'm looking at the spark on a scope and it looks exactly the same when the car is running perfectly and when it's cranking but won't start. I have no reason to suspect weak spark, but the spark timing is highly suspect.

thanks

Mark

Bill,

I monitored the MAP sensor output directly on the wire right next to the MAP sensor. I agree with you, the next step is to monitor the MAP voltage right at the ECM. I removed the glove box then ran out of time yesterday. That will be the next step.

But it's starting to look like an ECM issue. I ordered a cheapie on EBay.

Mark

I replaced the MAP sensor with a junk yard part...no change...

Next step... The car recently developed an exhaust leak at the front pipe to manifold flange. There is chance this is effecting the O2 sensor so I'm having that fixed... and we'll see what happens..

Mark

thanks Bill..

I'm looking for more in depth info...

Can a MAP code get set as a result, not a cause, i.e if something else casues the engine to stall and or backfire, can that unexpected pressure set a MAP code even though nothing is wrong with the MAP system?

Can an exhaust leak at the front pipe flange cause the O2 reading to gradually get the ECM calibrations screwed up enough to cause these symptoms?

The symptoms also seem to fit a distributor pickup coil problem but no code has been set for that.

I know in the end it will be something simple that caused this weird sequence of problems...

Mark