Just done a 4age swap and... (Its finally a runner!!!)

[skoty]

I've run into some problems Basically as I blew my last blue top 4age up I've replaced it with a new one in my gt but for some reason it wont even attempt to start. Ive checked over EVERYTHING such as the dizzy and the timing, fuel injection and injectors, compression, spark, ecu sensors you name it but wtf I think Ive missed something small, please help 4age enthusiasts!

[Adamal]

You've connected the battery, right?

But really, does it even attempt to turn over or what?

[skoty]

You've connected the battery, right?

I don't think it would be turning over if the battery was disconnected buddy No it doesn't even attempt to, Ive got a feeling Ive missed an earth lead somewhere

[AE85.6]

but if it was an earth lead or something wouldnt it have no power at all ?

[eightytrueno]

having VERY similar problem, going over to check it all out again now

check and recheck ALL your earths and power lines tho! this helped sort a lot of stuff out on ours lol dodgy wiring...

[evil_si]

ok do you have a multimeter??
if so check earth continuity between chassis and engine, between battery negative terminal and chassis , and engine should all be as low as possible like .001 - .008ohms

that should clear up the earthing

have you connected the ignition wire to the starter? that would be the only reason i can think of for not cranking.
check for 12v to the starter from the battery, check that the fusabile links are ok

[vvega]

is the igniter earthed ??
they need to be earthed to fire

make sure all the red and black have 12v applyed to then while cranking as well

onec you have that sorted check back

v

[skoty]

It does have spark as it turns over. I think the injectors arnt operating, someone told me if there is a bad earth to the injectors the car wont run either.

Also... obviously to run an engine you need spark fuel and air. When working with a carbed car it is a lot easier to illiminate a problem working with those few basic needs, however with EFI someone was telling me that say if one of the ecu sensors isn't working the ecu will work in 'limp' mode which basically overrides everything in order for the car just to run but not all that well obviously. Is this true?

[matt dunn]

It does have spark as it turns over. I think the injectors arnt operating, someone told me if there is a bad earth to the injectors the car wont run either.

Make sure that the computer earths are connected. the should bolt to the inlet manifold on top of the runners in abot the centre. Use a 10 mm socket.


Matt

[skoty]

Matt: You mean the ones on the part of the wiring harness that run past the intake manifold?

[matt dunn]

Matt: You mean the ones on the part of the wiring harness that run past the intake manifold?

yes they come out of the loom along by the fuel rail somewhere.
Quite often after an engine change people forget to srew them back on.

[4AGTE]

Just under the fuel rail on the left hand side the earth's bolt to the manifold. Its a 10mm bolt for this and i have made that mestake befor and took a little to sus it If thats the reason but its easily missed when putting the wiring loom back in.

[skoty]

Just under the fuel rail on the left hand side the earth's bolt to the manifold. Its a 10mm bolt for this and i have made that mestake befor and took a little to sus it If thats the reason but its easily missed when putting the wiring loom back in.

I'm sure thats what I've missed then , so the car wont even attempt to run while being turned over like in my situation?

[4AGTE]

wont even consider starting dude. Not even show a sign of it.

[M R 2 Mk1]

wont even consider starting dude. Not even show a sign of it.

Yeah I think anybody whos worked on a 4age finds that out eventually, took me an 1 1/2 of stuffing about yelling "motherf**er why wont you start" and then....oh thats all it is

[skoty]

We brought the 4age back to life...

Basically it was running far too rich and just continuously flooding itself, to solve this problem there was a special ecu sensor that was busted which from what I've been told determines the air/fuel mixture.

[spencer]

to solve this problem there was a special ecu sensor that was busted which from what I've been told determines the air/fuel mixture.

special sensor? could it just be a Map sensor??or ya afm??

[skoty]

to solve this problem there was a special ecu sensor that was busted which from what I've been told determines the air/fuel mixture.

special sensor? could it just be a Map sensor??or ya afm??

Nope it wasn't the MAP sensor.

[spencer]

what kind of special sensor controls your air fuel ratio maybe the temp sensor that goes with the map? Ive wired up a few 4ages and never come across this special sensor. I mean to make a 4age work there aint that many senosors ya need. Afm or map, air temp, tps, water temp and hall effect thingy in the dizzy. The comp will then use this info to know how much fuel to slap in and where to spark it

[skoty]

It was the temp sensor (the brown plug I think), apparantly if your temp sensor is fukd it tells the ecu to run to rich for some reason

Its funny that, as soon as I replaced that sensor, it started straight up no problems I'd checked absolutly everything including timing etc, but never thought initally the temp sensor would cause it to run too rich if faulty