Starting Issues - Need Ideas!

[DRFT33]

Symptom - Car cranks but does not start (hot or cold)

There is fuel pressure at the line, pump is operating and priming correctly. There is a good spark.

Now here is the confusing part - on initial start, there is no injector pulse. I thought easy fix, its probably my CAS. Changed with another working unit tested on another car. It starts! Switched the engine off. Try to start again, cranks but no start. Once again, no injector pulse.

When i remove the CAS and spin it by hand, the pump primes and the injectors pulses. Reinstall the CAS and it starts. But when I switch it off, same problem reoccurs.

I've checked all the main wiring loom, make sure there's no short to earth. I've checked all earths and wiring. The battery is new. Measures 12.4Vs and 14.5Vs whilst running (alternator is charging). Whilst cranking it drops to 10.2V which is acceptable.

My theory is that the starter motor is drawing too much current when cranking, causing the CAS not to send the proper signal. Does anyone have any further ideas that I might need to check? I know its hard to diagnose a car over the internet without seeing it, but just want to hear any other ideas just in case I have left something out.

By the way, the car did receive a whole bunch of upgraded bits. Just to name a few that might affect it - Bosch 040 fuel pump and Bosch 363 injectors with R32 GTR ballast resistor, Z32 AFM, 80mm Throttle body. The rest of the mods I fail to see how it could affect starting.

Cheers!

[heller44]

Check all your earth's, sounds like one is a bit off. First suggestion anyway.

[The Dan]

Get rid of the ballast resisters and put in injectors that suit the car.

Had exactly this problem with a customer with a PowerFC Pro and GTR injectors (Dano4127). ripped out the resisters, made a new loom for the SARD 550's I had laying around and bang, starts every time. It had something to do with the injector driver in the ECU not operating correctly with that particular setup. Spoke in length with contacts in Japan and it turns out some of them have different drivers to others so cannot be wired that way.

[The Dan]

Once the car started, it would be fine, but you needed to turn the cas to get fuel in there...then it would start using the fuel you injected, then continue to run after cranking had finished

[DRFT33]

That's a fair call about the injectors. I'm running a remapped RB20 ECU with Nistune.

My question is now, what's the difference between me turning the CAS by hand and the camshaft doing it whilst cranking? It should technically still prime and pulse the injectors whilst cranking?

[The Dan]

It could be dropping voltage to the injector drivers while cranking. It could be something to do with current issues with the resistors in place causing the drivers to not fire while the starter motor is drawing what it needs.

Just a thought.

I never went into it in massive detail as I could see the most uncomplicated solution so I just fixed it. I would have liked to know exactly why but unfortunately time was not permitting. Let me know if you find out the reason.

[Dose Pipe Sutututu]

If you think your car is drawing too much current, hence the voltage drop, does the car start when you roll start it?

like get 2 of your mates to push the car down the street, and clutch it to life, if that doesn't work that's not the problem then.

try starting the car without the AFM plugged in.

[blind_elk]

The problem would be less of the cranking voltage taking power from the injectors, and more of the cranking voltage taking power away from the ECU.

Try jump starting the engine.

[brother_david]

Sounds like the CAS is acting up, my car acted the same, would start in the beginning if you pushed it but it got worse and worse until it wounldnt start at all. Pulled the CAS and gave it a spin by hand, sounded like a peppergrinder Changed it and everything was good!

[mad082]

That's a fair call about the injectors. I'm running a remapped RB20 ECU with Nistune.

My question is now, what's the difference between me turning the CAS by hand and the camshaft doing it whilst cranking? It should technically still prime and pulse the injectors whilst cranking?

it could be that you have a broken cam (have seen this before in a mates ca18) or there is a short in the CAS so that it is earthing out when bolted to the block.

but i would be looking at other things first like voltage dropping when cranking

[DRFT33]

Cheers for the input guys.

Just to clarify, the engine does start but only after I have manually spun the CAS. As soon as the injector pulses, I can reinstall the CAS and it starts.

Its not the AFM and its not the CAS. When the engine is running, it receives all signals correctly and runs fine. I've checked the end of the cam to make sure there's no damage to the half-moon shaft.

I've just bought another starter motor and will be installing it this weekend.

[heller44]

So... the injectors aren't firing so you are changing the starter motor?

[The Dan]

So... the injectors aren't firing so you are changing the starter motor?

+1

Have you checked voltage at the injector while cranking?

You said up the top that the voltage drops to 10.2 while cranking. That's normal.

[R.3.2.G.T.R]

thread revival, didnt want to start new one, car wont start, only cranks

what i have tested so far:

fuel pump relay - ok

fuel pump primes - ok

fuses (in-cabin and engine bay) - ok

fuel pressure - 43psi

battery (13v, 11v whilst cranking) - ok

ignitor - swapped with another known working one

ignitor earth grounded - yes

voltage at injector - yes

pfc sensor check - ok

disconnected maf - still no start

spark with coilpack attached - FAIL

R34 CAS, yet to remove, however have read broken locator wont stop it starting

continuity testing to coilpack loom - yet to do

check voltage at starter motor - yet to do

broken cam - possible??

Q:

is cas and ignitor only culprit that would cause no spark issue?? any other things i can look at..

anyone wanna lend a R34 CAS i can test with??

[DVS JEZ]

if there is injector pulse than the CAS is ok, the ecu gets its firing order signal for injector and spark from the CAS so if one works then they should both work.

you need to check with an LED test light if theres a pulse on the ecu side of the ignitor when cranking, this will tell you if the ecu is sending the signal to the ignitor. it will be very faint when you check it.

if there is no pulse here the check at the ecu itself, if there is none here than you might need to try another ecu,

[R.3.2.G.T.R]

will PFC sensor check pickup the issue, as it came back normal

I'll open the PFC to check for burnt tracks and re-check wiring

any specific pin I should be testing?

Is there a relay near the PFC, I remember ages ago of one clicking in that area

[R.3.2.G.T.R]

update:

swapped in a new odyssey pc1200 battery, still no closer to getting it started

i have voltage at the injector plugs although this is different to injector pulse which i cant hear during cranking with screwdriver

if so, that would point the finger at the CAS right?

when measuring voltage at ignitor, do i have to earth out the E during cranking in order to get voltage reading?

also have re-plugged the ECU and relays near it, yet to test voltages at the pins

btw, car started briefly with the new battery for bout a minute, idled normally, could hear the injectors being their noisy normal self, then on its own it splutter few times and died

[STATUS]

cas pinout is different on R34 to R32, did you repin it?

[R.3.2.G.T.R]

cas pinout is different on R34 to R32, did you repin it?

i didnt but was done previously when motor was swapped, should i be looking at the wiring?

[R.3.2.G.T.R]

question:

assuming CAS is fine, and its the power wire to the coil in the loom thats broken or bad (ie. no spark), will cranking still cause injectors to wet the spark plugs??

i will pull CAS out over the weekend and rotate by hand to test if the injectors click etc

also only one of the relay by the ecu click with ignition on however 12v is present on both relays