Back probing with needles and clips @ 17:06 - why hadn't I ever thought of that!!! I only have one pair of proper back probes so I'll add this to my arsenal. Many thanks!
Spark looked like it was doing the 1 2 3 pulse thing too when you were doing the long crank. What does the imobiliser cut? Also what was the voltage between and after the injector pulses? Would be a good idea to id ecu power and grounds. Also for power tests use test light as multimeter will say bad connections are good due to it's high resistance. Lack of prime makes me think intermitant ign feed as it is happy sometimes.
Andy so far everything seems to checkout how about the immobilizer circuit. Possibly the ignition key or key battery if it uses a key fab. Just a hunch the way it keeps shutting down. Possibly bad alarm connections or poor solder connections on an ignition circuit board if the vehicle has one. Maybe as they heat up your losing continuity. Just some thoughts mate. Thanks for the challange
My first guess, too. I had a similar problem with a Chrysler LeBaron Sedan once and it turned out to be the aftermarket immobilizer that cut the power to the injectors.
I agree - the alarm's behaviour does not seem right to me; reminds me of a similar situation I had many, many years ago with a Ford Sierra that ended up with the alarm being repaired by a specialist.
Well done on your diagnostics. Curious, is that manual for a 3SGTE though, a few slight differences on the S series engines. I noticed that while turning it’s cutting out, which brings me back to my original comment about the VSV and the power steering pressure sensor and or vacuum leak. I’m gonna get my manual to confirm an idea...leaning towards MAF, those Bosch style sensors can go bad on the contacts inside. 🤔 again though, this is awesome walk thru knowledge of diagnostics people, and how it should be done. Throwing parts at stuff because you ‘think’ it might be a problem, and physically checking the parameters are miles apart.
Find out if the IGF and IGT wires are where the manual says so. If the distributor wires are moved, it is reasonable to assume the others have been as well. Then scope the signal coming from the ignitor to the ECU. ECU is complaining about not seeing a signal from there. Since a different ignitor doesn't fix the issue, my suspicion would be wiring between itnitor and ECU, and/or rev counter. Since the rev counter also gets its signal from the Ignitor, a grounded cable there might degrade signal quality enough to let the ECU not see ignitions, in which case it would stop fuel injection. In other words, find out why the rev counter isn't working, and you will find the reason why the engine isn't running.
If the alarm immobiliser system was the culprit... It wouldn't have started for so long as it did at the beginning of part 1 where Andy actually said he wanted to go for a test drive.
Good Morning chungaleta1234, I think you are correct. It's a fault that definitely occurs more once the engine/components have warmed up a little as the car, when started from cold, will run for a few minutes before the fault develops. However, once the fault shows for the first time that day then the engine only fires for around 6 revolutions of the crank before it dies due to no injector pulse. It could be a circuit board issue where a dry joint is loosing connectivity as soon as it warms up. This could be in the immobilizer if it breaks the IGF or IGT signal wire, the igniter or possibly even in the ECU. I think if it was a broken external wire within the harness it wouldn't be so heat specific. Anyway, must sign off now as I'm just about to start filming Episode 3. Cheers for your input... Andy
I'm a bit suspicious of the ignition relay still. You measured about 1.7V on the ground terminal and a reading of about 13ohms to ground on these terminals. But they should be connected directly to ground. Maybe 0.5ohm - but 13ohms is quite high. And if it's a poor connection and the current is high when closed, the voltage will increase significantly. There's a 40A fuse on it so I'd expect the current to be quite high. Even at 1A, a 13ohm connection will drop 13V. The injector voltages looked way low also - only about 1.4V? Maybe the poor ground connection on the relay is preventing the injectors working properly & the subsequent voltage rise at the relay is then shutting down the ECU? Interesting problem regardless.
+StopDropandLOL I'm starting to think along the same lines as you guys. To be honest any excuse to take that bloody alarm out! Well, I'll be back to it at the weekend so will take a look. Thanks for your input. Cheers Andy
sparks are firing at odd times. 1 long 2 quick 1 long. however, have you even checked the fuel filter. You did say the car is not getting fuel towards the end of the video. first thing to do i say. bypass the alarm and retry the car start up. 2nd check for the fuel pressurization. See if the filter can accept the flow and deliver the flow of fuel. Then go back to the sparks.
+jason puttock Hi, thanks for your input. Just to clarify, fuel pressure gauge is on output side of filter. Fuel pressure is fine - 1st video. I'll check out more on ignition circuit on next video. It's the injector pulse (opening signal) or duty cycle that's stopping. This is controlled by the ECU & I want to find out why it's stopping. Is it an ECU decision, a circuit issue or an immobilizer issue....we will find out soon enough. Cheers again. Andy
I would be careful to check the igf signal. Toyotas can shut down injectors to save the cat if the igf is missing. Take a look at this www.scribd.com/doc/224732136 in this case they are modifying the spark advance system and the igf shuts it down because it's not following the IGT instruction from the ECT.
I meant to say missing or not "as expected" by the ECU. I guess the IGF shutdown can protect damage to the engine by uncontrolled timing as well as the CAT from misfires.
Back probing with needles and clips @ 17:06 - why hadn't I ever thought of that!!! I only have one pair of proper back probes so I'll add this to my arsenal. Many thanks!
New drinking game......chug a beer every time the word “right” is said.
Spark looked like it was doing the 1 2 3 pulse thing too when you were doing the long crank. What does the imobiliser cut?
Also what was the voltage between and after the injector pulses?
Would be a good idea to id ecu power and grounds.
Also for power tests use test light as multimeter will say bad connections are good due to it's high resistance.
Lack of prime makes me think intermitant ign feed as it is happy sometimes.
Ivan just watches to see the Tool Girls :-)
cam or crankshaft sensor braking down under load. Where dose the rev counter get its signal from?
Andy so far everything seems to checkout how about the immobilizer circuit. Possibly the ignition key or key battery if it uses a key fab. Just a hunch the way it keeps shutting down. Possibly bad alarm connections or poor solder connections on an ignition circuit board if the vehicle has one. Maybe as they heat up your losing continuity. Just some thoughts mate. Thanks for the challange
it seems more like the alarm to me the way vit keeps chiming in just before you turn over the engine more so if after market
My first guess, too. I had a similar problem with a Chrysler LeBaron Sedan once and it turned out to be the aftermarket immobilizer that cut the power to the injectors.
Certainly worth exploring. Normally it's the fuel pump that is immobilised though on these.
I agree - the alarm's behaviour does not seem right to me; reminds me of a similar situation I had many, many years ago with a Ford Sierra that ended up with the alarm being repaired by a specialist.
I thimk the alarm as well
I thought an immobiliser completely cuts all power to the ignition. So it shouldn't fire at all.
Well done on your diagnostics.
Curious, is that manual for a 3SGTE though, a few slight differences on the S series engines.
I noticed that while turning it’s cutting out, which brings me back to my original comment about the VSV and the power steering pressure sensor and or vacuum leak.
I’m gonna get my manual to confirm an idea...leaning towards MAF, those Bosch style sensors can go bad on the contacts inside. 🤔
again though, this is awesome walk thru knowledge of diagnostics people, and how it should be done. Throwing parts at stuff because you ‘think’ it might be a problem, and physically checking the parameters are miles apart.
Bad ignition switch? Key reader? Alarm system?
Find out if the IGF and IGT wires are where the manual says so. If the distributor wires are moved, it is reasonable to assume the others have been as well. Then scope the signal coming from the ignitor to the ECU. ECU is complaining about not seeing a signal from there. Since a different ignitor doesn't fix the issue, my suspicion would be wiring between itnitor and ECU, and/or rev counter. Since the rev counter also gets its signal from the Ignitor, a grounded cable there might degrade signal quality enough to let the ECU not see ignitions, in which case it would stop fuel injection.
In other words, find out why the rev counter isn't working, and you will find the reason why the engine isn't running.
The manual being used is not for the 3gse engine, it's for the 3sgte and 5sfe. Hence why there are a few differences.
If the alarm immobiliser system was the culprit... It wouldn't have started for so long as it did at the beginning of part 1 where Andy actually said he wanted to go for a test drive.
Good Morning chungaleta1234, I think you are correct. It's a fault that definitely occurs more once the engine/components have warmed up a little as the car, when started from cold, will run for a few minutes before the fault develops. However, once the fault shows for the first time that day then the engine only fires for around 6 revolutions of the crank before it dies due to no injector pulse.
It could be a circuit board issue where a dry joint is loosing connectivity as soon as it warms up. This could be in the immobilizer if it breaks the IGF or IGT signal wire, the igniter or possibly even in the ECU. I think if it was a broken external wire within the harness it wouldn't be so heat specific.
Anyway, must sign off now as I'm just about to start filming Episode 3. Cheers for your input... Andy
Ahhh that sounds about right. Looking forward to that 3rd part.
I'm a bit suspicious of the ignition relay still. You measured about 1.7V on the ground terminal and a reading of about 13ohms to ground on these terminals. But they should be connected directly to ground. Maybe 0.5ohm - but 13ohms is quite high. And if it's a poor connection and the current is high when closed, the voltage will increase significantly. There's a 40A fuse on it so I'd expect the current to be quite high. Even at 1A, a 13ohm connection will drop 13V. The injector voltages looked way low also - only about 1.4V? Maybe the poor ground connection on the relay is preventing the injectors working properly & the subsequent voltage rise at the relay is then shutting down the ECU? Interesting problem regardless.
That alarm doesn’t have an immobilizer built into it does it?
+StopDropandLOL I'm starting to think along the same lines as you guys. To be honest any excuse to take that bloody alarm out!
Well, I'll be back to it at the weekend so will take a look.
Thanks for your input. Cheers Andy
I think i saw this car on the back of a tow truck going north the other day through the city haha
+SilentGamer Haha! Not this one! But there are lots of these in New Zealand.
sparks are firing at odd times. 1 long 2 quick 1 long. however, have you even checked the fuel filter. You did say the car is not getting fuel towards the end of the video. first thing to do i say. bypass the alarm and retry the car start up. 2nd check for the fuel pressurization. See if the filter can accept the flow and deliver the flow of fuel. Then go back to the sparks.
+jason puttock Hi, thanks for your input.
Just to clarify, fuel pressure gauge is on output side of filter. Fuel pressure is fine - 1st video.
I'll check out more on ignition circuit on next video. It's the injector pulse (opening signal) or duty cycle that's stopping. This is controlled by the ECU & I want to find out why it's stopping. Is it an ECU decision, a circuit issue or an immobilizer issue....we will find out soon enough.
Cheers again. Andy
O think the alarm is the problem maybe you shows desactivate the alarm.
I would be careful to check the igf signal. Toyotas can shut down injectors to save the cat if the igf is missing. Take a look at this www.scribd.com/doc/224732136 in this case they are modifying the spark advance system and the igf shuts it down because it's not following the IGT instruction from the ECT.
+Andrew Thompson Good call....I'll include this on the next series of checks. Cheers Andy
I meant to say missing or not "as expected" by the ECU. I guess the IGF shutdown can protect damage to the engine by uncontrolled timing as well as the CAT from misfires.
My car stalls after revving the car straight away from cold. If i leave it to rev until 1.5k its fine.
This stinks of a crapping out Crank or camshaft sensor. Seen this loads on Toyota's.
I agree, if this version of the MR2 had a crank or cam sensor I would agree. However, it does not! Cheers Andy
@@AndyMechanic Andy there is a cam sensor it's in on the distributor on these revision 2 Mr2s, defiantly no crank sensor.
Agreed....though don't fire the parts cannon just yet....next Episode....
Cheers Andy
classic toyota start and stall problem: dirty idle air control motor. i think you're going down a huge rabbit hole focusing on spark and fuel.