Ook's issues with Corolla - crank but no start - RESOLVED

The_Librarian

The_Librarian

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Best to start from the beginning.

Cold start issues on my Corolla. (car starts just fine when warm).

Symptoms feel like a definite loose electrical connection, but then again it may also be fuel-related, as a loose electrical connection will just cut out, whilst fuel starvation will means less and less power. So basically a combination of the two.

Checked out the distributor (yes, it’s that old) and found no loose wires or funky stuff except for the condensor which looked definitely iffy. The distributor is of the electronical type, so no points.

Chucked it out (the condensor) and problem still persists. Then the car started. (The issue may be cold-start related).

Somebody who’s in the trade informed me that with points you definitely need a condensor otherwise you’ll burn your points out. So we can only assume that that specific condensor was to suppress electrical noise. Tough for the guy whose radio/mp3 player will whine when I’m next to him with my car… hehehehe

Drove to the autoshop, got some brand new tools (my current tools is with the SO) and decided to tackle the throttle body.

Got some throttle body spray cleaner, went home and started to clean the patient.

The throttle body… it was dirty. It was filthy. It was black on the inside.

Like black sludge. Ewww.

Cleaned it to the best of what I can do, then while I was still busy spraying it, the little plastic pipe which you push into the nozzle of the spray can to get at hard-to-reach places, shot off and vanished into the throttle body innards.

Well, f***. That was the last thing I wanted. Pondered whether to leave it, then decided, nah, if it ends up cockblocking a valve, then I’ll have a major issue.

So… decided to take the throttle body off. It was when I found that there is a vacuum pipe missing. Looked all over inside the engine bay, could not find any trace of it. WTF??? But I found and removed the small plastic pipe which shot off the can of cleaners.

But I also noticed a nipple of the same size a bit behind the engine block - also without a pipe.

Did the hillbilly thing and applied a small blob of silicone sealant to both open nipples. (hurr durr). Put everything back together (after cleaning the inside part of the throttle body), and put it all together.

It may be my inagination, but the car definitely start easier now.

The following day I was greeted with a drizzle.

Tried to start the car, it just cranked.

I got a lift to work this morning. The above symptoms tells us that it is most probably a cold start issue.
 
This afternoon I traced all the sensors - and there is only one I'm not 100% sure of. I know that if it is disconnected, the engine warning light comes on. So this one is a high possibility.

The rest is for the cooling fan and temperature sensor, no other sensors so far. Gotta make notes of the locations of these for future reference.

Battery is put on charge for the night. It was cranked a bit flat.

Luckily I have an OWM (workshop manual). There are now three suspects.

1. Possibly the cold start sensor. Will have to verify that this sensor is what I think it is.
2. Trigger unit inside distributor may have given the ghost. Keep in mind car is over 20 years old, so...
3. Something Else. (Damn you Mr Murphy).

The OWM have instructions on how to test the coil and assorted components, I will test them tomorrow. Hopefully there will be parts available.

Interestingly, the manual said that the GTi 16V have the cold start injector and sensor, I did not see such an injector on my car as I have the GLe 16V.
 
Ive had a cold start issue on one of my cars that ended up being leaking injectors. But cold start issues can be quite a few things.
 
Given that it generally runs ok and just cold starts are an issue I would start with that cold start sensor.
 
Not sure what year yours is, but I drove several Corolla models (before my Camry), from 1976, 1987 and 1996 (only had issues on the oldest). All carburettor, but electronic ignition on the later models.

IMO cold start on older models is either spark (maybe cracked leads in damp weather), or automatic choke (that missing vacuum hose).

Did you try starting after depressing the accelerator to the floor once to get some fuel? That can sometimes work, or eliminate one scenario).
 
Gordon_R said:
Not sure what year yours is, but I drove several Corolla models (before my Camry), from 1976, 1987 and 1996 (only had issues on the oldest). All carburettor, but electronic ignition on the later models.

IMO cold start on older models is either spark (maybe cracked leads in damp weather), or automatic choke (that missing vacuum hose).

Did you try starting after depressing the accelerator to the floor once to get some fuel? That can sometimes work, or eliminate one scenario).
Click to expand...
It's fuel injected so no choke. The mixture will be enriched by the injection system based on input from the cold start sensor.
 
Sinbad said:
It's fuel injected so no choke. The mixture will be enriched by the injection system based on input from the cold start sensor.
Click to expand...

Noted. I never needed to work on fuel infection models, but they are definitely more complex. Still sounds like spark...
 
Have you tried changing the spark plugs and the ht leads as well as the cool ht lead?
 
I had a similar crank but no start issue, took two years to track it down to a faulty airflow/oxygen sensor that gave erratic readings. You're probably on the right track with the cold start or similar sensors.
 
According to this :


when measuring the coil, the primary coil must give a reading between 1.28 to 1.56kOhm

Secondary must give a reading between 10.4 to 14kOhm

Set the multimeter to 20kOhm, and measured. First measure (primary coil) drops down to zero. (Even the same when setting it to 2kOhm, then 200Ohm, the reading drops out).

Second measure (secondary coil) measures 11.4kOhm

Looks like the primary's gone and done it. Nuwe part se moer.
 
The_Librarian said:
According to this :


when measuring the coil, the primary coil must give a reading between 1.28 to 1.56kOhm

Secondary must give a reading between 10.4 to 14kOhm

Set the multimeter to 20kOhm, and measured. First measure (primary coil) drops down to zero. (Even the same when setting it to 2kOhm, then 200Ohm, the reading drops out).

Second measure (secondary coil) measures 11.4kOhm

Looks like the primary's gone and done it. Nuwe part se moer.
Click to expand...
If the primary was dead shorted surely a fuse would blow somewhere.
 
Shouldn't a simple test of the coil be to disconnect the coil wire while it's not starting and try to see if you are getting a spark?
 
TheChamp said:
Was it the one on the intake manifold? because the oxygen sensor is the one on the exhaust.
Click to expand...
Must have been, it was a case of going to multiple places that couldn't work it out, then someone took a second look at the readings from the OBD2 and saw a blip in whichever sensor it was, they swapped it out without me actually seeing where it was. I got to keep the old sensor at least.
 
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