Trying to help a mate diagnose his car, its a SC400 V8.
Drove it home one night, it never started the next day, or since.
It was minus 10 that night.
Transported it here, where it is now.
This is what I have found so far.
It has petrol. (not contaminated)
It has fuel pressure (not checked, but it is there)
Injectors are working. (clicking on turn over)
It has a healthy spark ( confirmed )
Timing belt has not slipped, (confirmed)
Compression test reveal all about 140psi except for one that is slightly lower.
It is sucking air into intake
Normal oil level
Changed the spark plugs with no effect.
Removed the exhaust, it is not blocked and I have pressure coming out of the exhaust when it is spinning over.
It is spinning over as fast as it should, and you can hear it coming up on compression when it is spinning over.
It does not start, splutter, cough or fart.
So, what is it ?
Does it sputter or cough if you spary start gas into air intake ?
Thats the next step, hes gone to get some.
Did it work?
do the plugs get fuel on them when you turn it over?
just tip some petrol in the intake.
The easy start made no difference.
The plugs are wet, so it shouldnt be overfuelling,
Changed ECU. Thinking about cam sensors but it has 2, so it should start lumpy.
The car drove fine to where it is now, and didnt break down. It just wont start any more :(
if you have good spark, compression and fuel then that could mean timing, could be a senor that controls it like the crank sensor.
Could be the crank sensor, but it is under the inlet and means a major strip down.
Hes going to spend the evening trying to work out if he can test it via the ECU Pins.
http://soarercentral.com/sc-forum/messages/1113/862.html
shows how to read fault codes by bridging some pins on the connectors.
Hes been through that already, he runs an equivalent site here in the UK :-D
what does the exhaust smell like ?
sounds a lot like a timeing problem to me...
i had a car that just wouldnt start one day, checked there was fuel and pressure, checked there was spark, just cranked over and over, turned out there was a dead cell in the battery and it didnt have quite enough current to do everything at once, tried a jump?
crank position sensor. has to be a timing prob if it DEFINITELY has fuel and spark and good compression.
His response :
QuoteHeres the thing.
If the crank sensor is not working, would it have a spark ?
NO is the answer we are looking for here. as the crank sensors tell the igniter when to chuck out a spark.
But what about the cam sensors ? as I said before I know if one is bad it will run, but be a pig to start, so they do not have anything to do with the spark (I think not )
The car doesnt have an alarm, and if it did it would have cut out either the fuel or the spark, and I ahve both.
I dont like easy start, so I got some petrol and squirted it into the intake while it was spinning over, and nothing, I even had a spark plug lead off to make sure it had a spark while spinning, while squirting while spinning.
So it had suck, it had fuel, it had spark and it had spin.
It has to be timing Shirley ?
But I am reluctant to take it apart until I find out what the problem is.
It is a 32 so it aint an easy or quick job to strip the front down, but I could do this and leave all the important bits connected and then spin it over after I have seen the timing marks to make 100% sure it aint slipped a couple of teeth.
What am I thinking ? I have checked the timing and it is good.
I lined up the crank shaft pulley with the mark, and checked both dizzy cap positions.
WTF can it be ?
Can the injector timing be off so it is always to wet to ignite even with starting gas ?
as said before, have you tried a jump, and a tow start ?
if you can get it running, you can see how its running, and maybe figure something else out...
like disconeting the plugs one at a time to see if it makes any difference... see if it has normal power etc...
also... sure he hasnt done anything silly like connected up the spark plugs in thew wrong order etc... ?
(if its pssible on these?)
also... this might sound too obvious.... sure he hasnt just flooded the sh*t out of it ?
Quote from: soopahflyHis response :
QuoteHeres the thing.
If the crank sensor is not working, would it have a spark ?
NO is the answer we are looking for here. as the crank sensors tell the igniter when to chuck out a spark.
But what about the cam sensors ? as I said before I know if one is bad it will run, but be a pig to start, so they do not have anything to do with the spark (I think not )
The car doesnt have an alarm, and if it did it would have cut out either the fuel or the spark, and I ahve both.
I dont like easy start, so I got some petrol and squirted it into the intake while it was spinning over, and nothing, I even had a spark plug lead off to make sure it had a spark while spinning, while squirting while spinning.
So it had suck, it had fuel, it had spark and it had spin.
It has to be timing Shirley ?
But I am reluctant to take it apart until I find out what the problem is.
It is a 32 so it aint an easy or quick job to strip the front down, but I could do this and leave all the important bits connected and then spin it over after I have seen the timing marks to make 100% sure it aint slipped a couple of teeth.
What am I thinking ? I have checked the timing and it is good.
I lined up the crank shaft pulley with the mark, and checked both dizzy cap positions.
WTF can it be ?
If the crank sensor is giving the wrong/no signal then it would have spark but would be at the wrong time to start the engine.
Ill check what hes found so far, but he cant tow start it. Its an auto.
the crankshaft sensor has been tested - has it been tested properly with an oscilloscope?
what sort of sensor is it? hall effect or otherwise?
It does sound like a timing problem. If the seller said the timing belt had been changed, you can bet it hadnt, and that the tensioners definitely hadnt been done.
It was..........
The timing. The belt had jumped 8 teeth overnight.
Various theories are being banded round to the effect of "Water leaking from the pump, filling in the teeth on the timing belt then freezing"
Quote from: soopahflyTiming belt has not slipped, (confirmed)
:mutley:
Much ribbing going on over in the soarer camp I can tell thee.