Engine wont start - need help

[speedmaster]

i know i can get more help here than posting in fB. so anyway i have a problem getting my engine to start. i spoilt 3 starters in 3 days! i had to tow the car in order to start it. when cranking, there will be times that the engine kicks back and flames coming out from intake. i have tried almost anything but i still cant get it to start. am i missing anything? i never had such problem before on 4a block, until i changed to 7A block.

my engine specs;

4age 20v blacktop
7a block
Kelford cams 266 @ 1.00mm / 10.50mm nett lift
83mm pistons (compression test at 290psi)
adaptronic e420d ecu tuned with tps (no map)
COP

is you need more info on the engine, let me know. i appreciate the help guys

[jondee86]

Sounds like a heap of compression for such long cams. Did you time
the cams to the Kelford cam card ? The book says normal BT compression
is 193psi, so maybe look at closing the intake cam a bit later to drop a bit
of static compression. You might also want to look at retarding the ignition
a bit to help starting.

If the engine starts and runs OK if you tow it to get it running, but it won't
start with cranking (and kicks back or locks), you are putting too much load
on the starter. BTW... sounds like a beast of an engine

Cheers... jondee86

[speedmaster]

Sounds like a heap of compression for such long cams. Did you time
the cams to the Kelford cam card ? The book says normal BT compression
is 193psi, so maybe look at closing the intake cam a bit later to drop a bit
of static compression. You might also want to look at retarding the ignition
a bit to help starting.

If the engine starts and runs OK if you tow it to get it running, but it won't
start with cranking (and kicks back or locks), you are putting too much load
on the starter. BTW... sounds like a beast of an engine

Cheers... jondee86

yes time to kelford specs - 102/105LC @ .025/.035



retarding the ignition wont help either

[jondee86]

Your Adaptronic will have a setting for ignition timing while cranking.
What do you have that set at ?

Cheers... jondee86

[allencr]

i spoilt 3 starters in 3 days! ...engine kicks back and flames coming out from intake.

FIX cam and/or ignition timing!!

[totta crolla]

How much valve lift a TDC (not compression) do you have ?
290 psi is a lot of compression have you checked that nothing, water, oil or fuel is leaking into the cylinders ?

[speedmaster]

How much valve lift a TDC (not compression) do you have ?

10.50mm nett valve lift

[totta crolla]

Valve clearances correct ?

[jondee86]

Hey Ed,
Just curious, but what does overlap have to do with cranking compression ?

Mike,
Just about everything. lol. More degrees of overlap equals more low rpm cylinder
bleed off.Here is a perfect example of how I learned this initially by accident....

I had a fairly stout 454 12.00-1 compression hyd cammed motor years ago with
a mild cam with very little overlap, but it was a 110 deg LSA cam from Comp.
Cranking Compression was very near 300 psi. Actually it was 290 to 296 psi

That thing was tough on starters and frequently busted them at the most
in-opportune times, like in rain storms etc. It was so bad that I carried tools
and a spare starter so I would not be stranded.

Then I changed the cam to a super radical 108 LSA high duration cam with tons
of overlap. Intake manifold and carb were the only other changes. Same ignition
and same ignition timing at first. Cranking compression changed immediately
to 160 - 166 psi. Engine spun over easier and it took much less amps to get it
started.

That started me on my journey to find out why. That was back in 1977 when
I started to learn about Dynamic Compression and how it was affecting my engine.
Now it was quicker, meaner, started easier, and idled like a John Deer Tractor
on steroids.

I love a good story It doesn't address the question of IVC which actually has
more effect on cranking compression. But I couldn't find a good story about IVC,
so this will have to do for starters

Cheers... jondee86

[speedmaster]

Valve clearances correct ?

Yes all correct

[totta crolla]

I love a good story It doesn't address the question of IVC which actually has
more effect on cranking compression. But I couldn't find a good story about IVC,
so this will have to do for starters

Cheers... jondee86

I once experimented with twin cam timing and setting it up by using a compression tester, figuring that the higher the compression the more air was getting in.
All went well on the inlet side and I could see up to 40psi increase on the gauge. The exhaust side was a different story and it seemed that the more overlap I gave it the higher the compression went, great until I tried to run the engine. It would only just start and had no power at all. Resetting the exhaust cam to factory specs. saw a great improvement.
So what was happening was that by having a large exhaust overlap meant the engine was simply drawing the exhaust back into the cylinder, the compression tester didn't much care where its air came from and was happy to give a reading. The engine of course was not at all happy with re-compressing 'dirty' air and would hardly run.

[speedmaster]

I love a good story It doesn't address the question of IVC which actually has
more effect on cranking compression. But I couldn't find a good story about IVC,
so this will have to do for starters [emoji38]

Cheers... jondee86

I once experimented with twin cam timing and setting it up by using a compression tester, figuring that the higher the compression the more air was getting in.
All went well on the inlet side and I could see up to 40psi increase on the gauge. The exhaust side was a different story and it seemed that the more overlap I gave it the higher the compression went, great until I tried to run the engine. It would only just start and had no power at all. Resetting the exhaust cam to factory specs. saw a great improvement.
So what was happening was that by having a large exhaust overlap meant the engine was simply drawing the exhaust back into the cylinder, the compression tester didn't much care where its air came from and was happy to give a reading. The engine of course was not at all happy with re-compressing 'dirty' air and would hardly run.

Did you had a hard time cranking to start the engine?

[jondee86]

The exhaust side was a different story and it seemed that the more overlap
I gave it the higher the compression went,

It is not hard to see that advancing the intake cam for more overlap will close
the intake valves sooner and trap more air inside the cylinder. But it is hard to
see why retarding the exhaust valve would give more compression

Of course, when the engine is running, the inlet side is likely to be under vacuum
while the exhaust side is under pressure. So yes, as you say, keeping the exhaust
valve open into the intake stroke will allow more exhaust gas to enter the cylinder,
especially at low rpm's. At higher rpm's the scavenging effect of exhaust flow is
greater, and overlap is more inclined to draw fresh charge out into the exhaust
(over-scavenging).

I tested a lot of different cam timing combinations ond came to the conclusion
that the rule of thumb used by Billzilla was actually right on the money. Stock or
shorter duration cams set at around 110/110 and longer duration cams (>272 deg)
set at around 100/100. I don't know what the static compression would be on the
7AFE+20V combination, but I'm guessing it might be quite high to start with ?

But race engines being what they are, it is not unusual for them to have to be
push started. TQ midgets, big single race bikes, Indy cars... they all need a bit
of help to get them fired up

Cheers... jondee86

[speedmaster]

too high of a cam that will have this issue. can it be solved with a 16v battery?

[jondee86]

Big high cranking pressure race engines often use high power custom built
reduction starters. The motor power and the reduction ratio are chosen to
both to be able to turn the engine over, and to spin it fast enough to catch.
Custom starters for race engines will usually be 24 volts.

So what happens if you put 24V on a 12V starter ? The starter will spin faster,
have the potential to draw twice the current, and deliver twice the power
that it was designed for. As starter motors are short-term rated even at
12V, running them at 24V will kill them quickly unless the engine fires up
after only a couple of seconds. Of course, this depends on the load on the
starter. A standard compression engine that starts easily will not overload
the starter. A high compression engine that is a hard starter and needs a lot
of cranking, could melt the windings in 20 seconds.

For high compression 4AGE engines there are two possibilities. The first
is the reduction starter from the AE92 16V which is said to work better
than the stock AE86 starter. The second option is to upgrade to the 1G
starter as outlined below. A simple adapter is required to get the iG starter
to align with the 4AGE flywheel. If you are able to use this on the 7AFE block,
it might be an answer.

Niteparts/Tama Autos 4AGE hightorque starter adaptor kit- NZ$95
Designed in conjustion with Tama Autos (oldschool toyota parts) this adaptor
kit allows the use of high torque 1.2kw 1G-GE and 1G-FE late model starter
motors with your 4AGE RWD and FWD applications.
Great for that high-compression naturally aspirated monster 4AGE or just
an easy upgrade from your old tired starter!

Please contact brendan@niteparts.co.nz regarding parts sales.

Toyota 1G starter with a custom bracket to hold the ae86 oem heat shield,
and an adapter plate to mate with the T50 bellhousing. Comes with hardware.
This starter served me well for the past 4 years (blacktop swap) but I recently
rebuilt my OEM starters and decided to go with those instead. I bought this on
yahoo japan auction. It cleared my OBX header and silkroad header. Dunno if
it'll fit with an oem header. VERY compact design. I can remove and install this
baby without jacking up the car or unbolting the header (just make sure you have
a swivel ratchet). In case you didn't know 1G-GE engines are 2.0L inline sixes.

Thanks to VitriumGTS for the pics...



Cheers... jondee86

[totta crolla]

What is the static compression ratio of the engine ?
Is the Adaptronic running a calibration that has already been proven to work ?
Does the engine turn over better if you disconnect the ignition leads ?

[jondee86]

These are the cam specs...



Cheers... jondee86

[speedmaster]

Mine is slightly different for exhaust

[speedmaster]

This is my cam card

[totta crolla]

Yep missed the @ 1mm bit
edited....

[totta crolla]

Incorrect firing order ?

[speedmaster]

Firing order is correct.

Will it be fuel pump problem?

[jondee86]

Your Adaptronic will have a setting for ignition timing while cranking.
What do you have that set at ?

Cheers... jondee86

[speedmaster]

Your Adaptronic will have a setting for ignition timing while cranking.
What do you have that set at ?

Cheers... jondee86

I will send you a snapshop

[jondee86]

I've got an e420c in my car, and I think the software is the same as the e420d.
On the Corrections Page, down at the bottom left hand corner, there is a checkbox
for setting the ignition timing during cranking. This means the timing is retarded
only during cranking, to help the engine start.

For example, I have 15deg timing advance at idle, but cranking at 9 deg advance.

And I have just been out in the garage trying to fix a problem with my engine.
When I put the CAS back in it went one tooth too far advanced. I can tell that
immediately, because when I cranked the engine it went... crank... crank... UMPH !!
The spark fires too early while the engine is still on the compression stroke, and
the combustion pressure stops the piston dead before it reaches TDC. Out the
CAS and turn the gear back one tooth, and it fires up immediately.

Cheers... jondee86

[speedmaster]

Yes crank crank uumph