4age bluetop wont start **SORTED!!!**

[l1ttle_d3vil]

Got a bit of a problem with my ke35 / 4age bluetop. I'm running an ae86 ecu / loom etc and have been doing so for the last 12 months without any problems at all.
Bit of background - for the last one or two weeks its been getting a bit harder to start from cold, just gota crank it over for a while with my foot on the gas. I put this down to a faulty cold start injector or something along those lines, then the other day noticed it missing a couple of times under higher revs as if the timing was a bit wrong or something.
Couple of mornings later I went out, started it, then as I started reversing it stalled and it hasn't started since.

So far I have replaced:
* Spark plugs (they were quite black)
* ECU
* Coil / ignitor
* Distributor

Injectors have power, I can hear them clicking and also the cold start injector clicking. The spark plugs were wet so fuel seems to be getting through, and its not getting blocked at the filter or anything. There is spark at the spark plugs. The distributor was bolted / clamped so couldn't have moved and upset the timing by itself.

What else am I missing?? has anyone else got any ideas?? I'm going to get hold of some other tools so I can test everything easier, check fuel pressure, reset timing properly, check compression etc. In the mean time is there anything else I could check? I've checked all relays, they're all OK and working.
The only other thing I've noticed is the engine was going through oil a bit more recently, but not sure if it was just as a result of taking it on a long trip after lots of town driving. If the engine has lost compression would it crank over easier like when the spark plugs are removed? or would that only occur in major loss of compression?

cheers
-matt

[thaphatty]

Sounds like you know the basics so just incase anyone doesnt know (good analogy to remember )

a car wont start without the facts

Fuel
Air
Compression
Timing
Spark

and only a major loss of compression. it would be rare to lose compression on all 4 cyls=catastrophic accident.

Checked all 4 sparkplugs for spark? not just one? timing is dead right when you replaced distributor? Does it start if you drop start it?

[l1ttle_d3vil]

yeah it still has a pretty decent amount of compression there so highly doubt its that. haven't tried push starting it, only two other girls in the flat and they don't seem keen to wana push start it

i only checked one spark plug, although it did look like a weakish spark.
I'm not 100% sure on the timing, but it should've been enough to atleast get it trying to fire...plus I was rushing to beat the storm!
I'll check the fuel pressure, compression, timing and spark on all 4 plugs tomorrow properly so I can be sure its all going.

good to know there is nothing really obvious ive missed (ive learnt something in building this car!!) i cant think of anything else off the top of my head which could cause this, other than maybe wiring has come loose somewhere along the lines but im guessing the problems with starting is related and something has slowly worn out to the point it wont start - not consistent with a wire coming loose.

will see what I can find out tomorrow...weather permitting

[big_boy]

check the air gap in the dizzy
& un plug the cold start injector & see what happens
also if you say your useing a bit of oil check that that hasent all built up in the TPS

[l1ttle_d3vil]

check the air gap in the dizzy

the what?

will check the other stuff you mentioned. thanks

[big_boy]

in the dizzy put a fealer gauge between the rotor & the pick up & check the gap is right

when you get your fealer gauges out its the brass one not the steel ones its about 15tho from memory

[l1ttle_d3vil]

ok i've figured its got no spark, for some reason it had a small spark yesterday though. definitely nothing at all there tonight though.
unplugged the cold start, no change. i've tried two different dizzies, both with the timing setup accurately and still nothing. compression was 125 on #1 cylinder, didn't check the rest as theres no spark before it even gets to the compression point

I've checked all the connections between the dizzy / ecu, and the ignitor / ecu and they're all fine. also not the ecu which is faulty.
there is power at the coil / ignitor, so pretty sure it isn't any of that wiring come loose. all I can think is it would be the coil and / or ignitor which is faulty, I've tried a different one but it had different plugs so had to wire it up temporarily - may have got something wrong.

Is there any easy way to test my current coil and ignitor though? From memory don't auto electricians have a tester they can connect them up to, or is that just the coil??

cheers
-matt

[thaphatty]

just need to test the resistance of the primary windings in the coil (ie across the positive + negative - not the HT point) and make sure the resistance is within factory spec

because it sounds like your windings are shorting out to me, happens quite frequently.

try using a certified non-bung coil and if it has good spark, then now is the time to go out at purchase that GT40R you've been meaning to get

edit: also make sure the positive of the coil and the HT point do not have continuity

2nd edit: you dont know you have weak spark till you test with your tounge

[Alex B]

have you checked the actual fuel pressure?

[l1ttle_d3vil]

haven't actually checked the fuel pressure, but the spark plugs are definitely wet with fuel when I take them out, so pretty certain thats not the problem.

just checked the + and HT point for continuity and there is none. checked the + and - of the coil though and they have continuity, when I turn the key on the - terminal gets 12v, been like this for the last year or so though iirc.

how would one go about checking the resistance? which setting on the multimeter do I use, and any idea what the factory specs are off the top of your head?

and I was just going by eye, spark looked alot fainter than usual - im pretty sure it is alot weaker now though as I can't even see it... I wonder if there really is no spark at all

thanks for the help. hopefully getting closer to the problem...

[big_boy]

1.4 ohm for a ballest 2.6-3.1ohm for a non ballest depending on brand but its normaly written on them in some way

like 12v 4A so its got to be 3ohms ect

[l1ttle_d3vil]

its a standard 4age coil + ignitor, not an aftermarket one or anything...non bellest I think.

but either way, i just checked it and couldn't really get any sort of reading. wasnt sure if I had the right setting so I tested it on all the settings - 20M, 2M, 200K, 20K and 2K.

on 20K it would flash up to about -0.59 for a second then if I held them on the terminals it would go to 0. on 2K it was something like .029...
I checked the second coil out of interest too and it was similar.

does the ignitor need to be removed from the coil first though, so its just the coil by itself i'm testing?

so whats more likely - both coils are stuffed, or I was doing it wrong?

[big_boy]

yes inighter needs to be removed

it sounds like your measureing the inighter to me from your results

your muiltymeter needs to be on its lowest setting on mine its 0-20ohms but on yours it sounds like its 2k

[l1ttle_d3vil]

i got a brand new coil tonight to try out, checked the resistance out of curiosity and got the same result as with my old one.
on 2k ohms I get a reading of .003; on a brand new coil. this is with the ignitor etc completely disconnected, and putting one multimeter terminal on the + coil terminal and the other on the - coil terminal. is that correct?

what about the ignitor itself? any way to test if thats shat itself?

[rollaholic]

0.003 on 2k setting = 3 ohms

[l1ttle_d3vil]

yep thought so...so new coil is definitely fine. old coil is showing between 1 to 1.5, so seems its faulty (disregard the previous readings!). still got no spark though.
ive checked all the wiring at the ecu, earths, power, batt signals etc etc and they're all fine.
Only strange thing I noticed was #12 and #18 pins on the 18 pin ecu plug weren't connected to an earth, they're for the tps, map, tha etc. another loom I checked was like this, I assume these sensors are earthed from inside the ecu or something, similar to the injectors?

[big_boy]

hang on you may now have the rong coil if your old 1 is about 1.4ohms then so should your new one if you old 1 is jumping up & do it may be stuffed but if is closer to 1.4 than 3 double check it or you will get a very weak spark if you put a 3ohm in insted of a 1.4ohm

[rwd_mayhem]

i had sorta the same problem with my ae70 4age, when i turned the key the motor would just turn over and not spark, but when i let go of the key it would spark in that small second between on and start. so it was a huge mish to get it started had to turn the key let it go, turn the key let it go etc, until it got to the right point and it would start but run like shit. turned out that as i turned the key to start all of the power was going to the starter and none to the dizzy, i took it to a sparky he fixed it, had no problems so far, did cost a bit but i had to get heaps of other things done too, definatly worth it in the end.
and this happened just randonly as well, one day it just wouldnt start properly.

[l1ttle_d3vil]

fairly sure theres no spark at all on the new one - not just a weak spark.

like 12v 4A so its got to be 3ohms ect

both old and new coils have 12v written on them...

rwd_mayhem: was it just your dizzy which wasnt getting power?? very interesting, was it just losing all voltage as soon as the key was turned to start? any idea how he fixed it??

[big_boy]

if you have a test light put that accross you dizzy while cranking & see what happens

it should flash

also if they both have 12V you should be all good