car fires up, then revs drop and stalls. will not run. help!

[deaf_rattle]

as i said before sounds like i/c piping, sort that out to eliminate that possibility

[jondee86]

There is a thread on Toymods that touches this subject. It indicates that
it is probable that Gen 1 and 2 had a ballast resistor, but Gen 3 did not
(on account of having high impedence injectors).

I've extracted a couple of comments (edited for brevity):-

I have what appears to be a gen 1 1G-GTE - yellow ECU plugs
and injectors - in the yellow wreck in the garage.

Also, the hoods on the injec connectors are brown and grey, however
the ECU's label only has '1G-GT" on it ??

It has large ballast resister for injectors under the bonnet - has three
wires: presumably one for each bank of injectors and the third going to
ground, tho it rejoins the wiring loom before doing so. I would think that
without it, the injectors will pull too much juice and you'll either fry the
driver circuits in the ECU or the injec's will pop.

To check for your particular engine, confirm the impedance of
the injectors - if the are 2.8 ohms you will need the resister if they
are 13 or so ohms you will not.

If the resistor is wired anything like a 4A-GE, then there will be a 12V
feed from the ignition to the resistor, and two wires from the resistor,
one for each bank of injectors. The injectors will be switched to earth
by the ECU.

From reading your original post, it would appear that if you have a Gen 3
engine, you should have high impedence injectors. In which case you
don't need the ballast resistor, and you should be running 12V direct from
the ignition to the injectors.

Cheers..... jondee86

PS: And yeah.... since the purpose of a ballast resistor is to drop voltage/
limit current; if you ARE using one with high impedence injectors, there
probably won't be enuff juice getting thru to drive the injectors......

[Malcolm]

try attaching the AFM directly to the throttle body, this may require copious use of duct-tape to make it join up without leaks, but this will eliminate all the intercooler piping and tell you whether there's a problem with that or not. Where abouts in Aucks are you?

[snwtoy]

I think you have the wrong approach here...

This is the perfect excuse to go aftermarked engine management

[lofreq]

thats really valuable info about the injectors and resistance. i will measure the injectors tomorrow and report on their rating. the reason we are trying to wire in the resistor is because it came with the soarer that the 3rd gen 1ggte came out of. so we thought, just put everythign back to how it was.

the resistor i have is only 2 wire, so im guessing it applies resistance across the main feed, then each bank of 3 injectors that fire already are reduced in voltage. problem is, where to wire it in!

however if the injectors are high resistance already then i guess i dont need it. which doesnt help matters since we didnt initially have the resistor in there, and she still did the same thing (fire up, run but slowly die) it sounds like its running off the cold start injector, then running out of fuel and dying.

im trying to find a length of hose to bridge the turbo outlet to intake mani ports (bypassing intercooler) so i can ensure no leaks... will do this tomorrow at the same time of measuring the injectors.

car is at my parents place, Howick. im in St heliers, my driveway here is too steep to push a dead car up so i had to leave it someplace else... if youre closeish by and want to swing by, i will probably be spending as much of next week from monday onwards working on it to get her fired up so let me know if you might be able to swing by! 027 5563737 - nigel

thanks a bunch!

ps: zam - aftermarket ecu will come later when i pay off this current expenses - together with single turbo mani, ext wastegate, new IC and surge tank. dont have money for it now - just want it running as per stock for now.

[Malcolm]

the two wire ballast resistor, are you sure it wasn't a fuel pump resistor? Don't know a lot about 1G-GTE's but the 3S-GTEs had a fuel pump resistor that is switched into the circuit when cruising to reduce fuel pressure and I guess, pump wear. Most injector ballast resistors I've seen have a single wire in, then enough outputs to go to each resistor (so a 4 cylinder has 5 wires).

I might be heading out east sometime next week, so if you're still struggling then I might come and see if I can help at all

[lofreq]

man. the resistor was next to a relay that we assumed was the fuel pump relay, in the soarer. we unscrewed the resistor... and took that to be the injector resistor. crap! maybe it is the fuel pump resistor and the motor doesnt need a ballast resistor!

if so then even more baffling is, what then is the problem!!

i'll measure the resistance of the injectors tomorrow and let u all know, and also try to seal off the intake piping... but yeah im stumped as to what to try next - feels like ive tried everything :/ if youre out that way do let me know so i can show u the car... thanks

[jondee86]

Looking at the wiring diagram, it seems the fuel pump gets a direct
feed at high engine load, and feed via the fuel pump resistor at light
loads. Sitting in your garage would be light load. Sooooo.... with the
fuel pump resistor out of circuit, when the ECU switches over to the
resistor, there will be no feed to the pump.

You can either put the resistor back in, or bridge the Fuel Pump
Control Relay terminals 2 and 4, so that the pump gets 12V no matter
what the ECU reckons it should have

Cheers.... jondee86

[lofreq]

makes sense - the setup right now does not use the fuel pump relay because the wiring for the fuel pump etc is now running off my cressida's system which doesnt have any pump resistor. right now, when the AFM is opened by any amount, the fuel pump comes on and stays on as long as the flap is opened. perhaps at idle, the ECU is sending a signal down ANOTHER wire, which should have gone to the resistor - but perhaps that is hanging somewhere unconnected hence no fuel pump running at idle - thanks for the lead i will check it out!

ps: merry xmas everyone! my christmas will be merry if santa clause fixes my motor tomorro!

[jondee86]

Refering to the 1G-GTE wiring diagram, the fuel pump is powered from
the start circuit when it is energised (during cranking). As soon as the
engine fires and the AFM comes off the stop, the AFM switch maintains
power to the pump (via relays).

The AFM switch is open circuit when the AFM flap is fully closed, but closes
as soon as the flap opens just a small amount. If you have to hold the flap
open to keep the fuel pump running, maybe you have changed the setting
of the AFM switch ??

You can bridge the switch out by connecting terminals 1 and 2 on the AFM.
Cutting power to the fuel pump when there is no airflow thru the AFM is a
safety thing, and you should not drive the car with the switch bridged <=
Mandatory OSH style warning.

Cheers..... jondee86

[lofreq]

i have to hold the flap to keep the ENGINE running - not the fuel pump. fuel pump stops when the flap closes, as its supposed to

heres what i have done so far:

1) bypassed intercooler with a pipe running from turbo outlets direct to the inlet pipe to the throttle body. AFM in factory location and all hose clamps tightened down.

2) i have bridged the wires in the AFM like you said, as a test - confirmed that the fuel pump now stays on all the time when ignition is set to ON.

so regardless of resistor, the fuel pump is working all the time the key is in the ON position. that rules out the 'low pressure mode' thing...

3) i have removed what we thought was the "ballast resistor" and wired everything back to how it was.
checked resistance on the injectors - 14ohms or thereabouts on each one ( +/- 0.3 ohms). this suggests that they are high impedance injectors and thus do not need a ballast resistor... yes?


after all that - she does the same thing - fires up for about 3-4 secs then slowly drops revs to stall.


how do i test to see if the injectors are pulsing? i now reckon the AFM is fine, and its something somewhere that is stopping the injectors from opening, so its dying when it runs out of fuel from the cold start injector.

problem is, i thought only the ECU is controlling the earthing of the 2 banks of injectors... so if they arent earthing then the injectors dont open so i get no fuel... what else would cause the injectors not to work??

[lorolla24]

Hi, not sure if im much help but i had a simalar problem when i did a engine swap with a 4agze in to replace a 4afe in my corolla, took me ages to work it out.
After about a week we found that the fuel pump relay would flick on for a second when you turn the key, which puts a small amount of fuel pressure in the lines and when you crank it would start but stall seconds later. because of 2 different fuel pump relays between the engines there was no signal going to the relay to keep it contacted which keeps the fuel pump going. Think the signal came though the "circuit opening" relay.

Try searching for that or to problem solve just baypass the relay and get the fuel pump hooked straight up th power.

Hope it helps..

Cheers
Rob

[lofreq]

thanks for the tip. i hooked up a test light to the fuel pump so i could see exactly what it was doing at all times. pump comes on when key is set to ON, and remains on during cranking etc. so fuel pump going all the time.

also had the coil sorta laying in the engine bay - not bolted down. i suddenly thought it may need to be earthed somehow. bolted that down - no difference.

now battery is dead - again. no battery charger here so its gonna have to wait till tomoro, i'll get one from warehouse - bah another $99 gone (i think they are that much?)

keep the suggestions coming!! im gonna keep trying to get this bitch running!!!

[Punter]

no battery charger here so its gonna have to wait till tomoro, i'll get one from warehouse - bah another $99 gone (i think they are that much?)

Paid $30 for mine from ripco, Its pretty slow to charge you have to leave it overnight.

[jondee86]

Yup... you have high impedence injectors. Now try this....

1. Check that you have voltage at ECU terminals 10 and 20 with the
ignition switch ON (test between terminals and body ground).

2. Check that you have a good earth connection between ECU terminals
E01 and E02 and body ground.

3. Injector operation can be checked with a mechanics stethoscope for
a rpm related "ticking" sound. Or by putting the end of your finger on the
injector body and "feeling" the injector opening and closing.

I've never had to try either of these methods, but this stuff comes right
out of the Toyota manual

Kind of interested in that you can keep the engine running by holding
the AFM flap open. Do you mean it will keep running even after the cold
start injector has closed ??

Cheers.... jondee86

[lofreq]

will check what you said tomorrow, will swap battery and charge the dead one. will also try the 'ticking injector' touch test, but i hope its apparent what i am supposed to be feeling for.

when i say "i can keep the motor running": if i do not touch anything, the motor revs up then dies smoothly, within about 5 seconds. if you quickly stick your hand in the AFM and press open the flap while it initially fires, with a bit of variation you can get the motor to run a bit longer, the revs (which usually drop to zero) rev back up again, and the motor surges perhaps around 1500+rpm, up and down, you have to keep adjusting the flap to get the motor to not die. however this only extends the run time to about 20 secs at the most, after about 15 secs the motor starts sounding like its misfiring and dropping to 5 or 4 cyls... then no matter how much you manipulate the AFM, it slowly dies anyway. so max run time with AFM tomfoolery is about 15-20 secs. run time without touching anything = 3 to 5secs

thats about as accurate as i can describe whats happening. does that sound like something specific is happening there?

[jondee86]

To die smoothly and cleanly without misfiring or "chugging" indicates a
clean fuel cut. Exactly what could be expected when the cold start injector
closes.

I don't know exactly what fiddling with the AFM does, as the ECU takes
signals from both the AFM and TPS when deciding how much fuel to supply.
But misfiring and surging as you describe would seem to indicate that at
least some fuel is being injected by the main injectors. But not enuff to keep
the engine running.

A bad earth on the injector ECU circuit could create enuff resistance to
prevent the injectors firing properly.

Cheers.... jondee86

[lofreq]

crap. heres a revelation - if i have the fuel pump running when car is set to ON position (motor is off, waiting to crank) and i unplug the fuel return line... shouldnt the return line pressurise, and start pissing fuel out? (well, if it was connected to the fuel return, it would send the fuel back to the tank, correct??)

i unplugged my return line, and turned on the pump - and nothing came out. its bone dry inside. surely i expected SOME pressure in there... shouldnt i?

now im thinking i have a problem in my fuel delivery. the fuel comes from the line running along the chassis rail... goes to a steel line with banjo fitting. we bolted this to the BOTTOM of the original 1GEU fuel filter... bolted the 1GGTE fuel line to the TOP of the fuel filter. this line then runs to the injector rail, at the BACK of the motor (firewall end) into another banjo fitting that also looks like a mini diaphragm, but no vac line on this end

the other end of the fuel rail has another similar diaphragm, but this time with a vac line connected to the intake plenum. i assume this is the factory regulator (so what the heck was the first diaphragm for?) from this fitting, the return line goes back down to the return line of the car (this is what i unplugged to test and it was pretty dry)

now, i know that fuel is getting at least as far as the banjo at the firewall end of the fuel rail - because we had that fitting loose, and on cranking the car that end started pissing out fuel everywhere. so ok, thats good, but after tightening it up, perhaps no fuel (or only a very tiny amount) is actually getting through to the fuel rail. is this possible? do the banjo bolts need to 'line up' somehow? perhaps thats why i have no fuel in my return? were we correct to connect the fuel feed to the bottom of the factory filter, and the output from the top of the filter to the rail?

if i unscrew the FPR end (radiator end) banjo, should i expect gas to piss out there? im gonna try this now, i have a feeling that it will be dry in there,...

please let me know if the way i described the fuel path above sounds correct!

does the above sound correct?

[lofreq]

ok heres the result. since no fuel was coming out the fuel rail at the exit side, i then unbolted the "dampener" so the banjo was free in the breeze. primed the fuel line for a second, and got a shitload of fuel out of there, healthy as.

this means - the fuel pump is fine, the lines are fine no crimps, the filter is fine (not blocking the flow) - fuel is getting right to the 'dampener' then stopping almost completely and shit-all is getting past it into the rail

looked at this dampener thing - there are NO feed holes thru the middle of the bolt!!! how the hell is it meant to work? the bolt is hollow, but i looked up the hollow and it leads to nowhere. there are no holes going thru the bolt perpendicularly, to allow the fuel to get thru and into the rail.

is this what its meant to look like???

[jondee86]

Sounds like a typical Toyota fuel rail. From the top of the filter is good, and
from there to the "pulsation damper" and in to the rail. Banjo orientation
should make no difference. At the other end of the rail the fuel pressure
regulator is trying to hold about 30 psi in the rail.

If your pump is supplying fuel at better than 30 psi, with the engine off and
the ignition on, there should be a heap of fuel running back to the tank in
the return line. If your pump can't make 30 psi, then the FPR will be closed
and the return line will be dry.

This doesn't mean the engine won't run at all, because if your pump is
making 20 psi, your fuel rail will operate like a returnless system. But with
low fuel pressure the amount of fuel injected will be less than normal. If the mixture becomes too lean, the engine may not run

Cheers...... jondee86