4agze stuck in limp mode

[Intense]

Went on a cruise today and the car was performing fine the whole day, then on the way home just slowing down to turn left, it stalled. So I restarted it and it started up, but wouldn't rev. Also the idle was going very low on the verge of stalling and then up and then down again, so it was hunting idle. The car had plenty of oil and water and I wasn't even pushing the car hard because it was raining today so what could possibly cause this problem?
I'd put my foot flat to the floor but it seemed to have no power. Could it be a small problem like a plug coming loose? Any suspected component's I should look out for. It's an ae101 4agze with map sensor, couuld a faulty map sensor cause this?
Any help will be greatly appreciated

[TERRA Operative]

Check for boot leaks, also loose plugs etc.

Can you pull any codes?

[Intense]

Took it to toyospares and they couldnt pull any codes from the diagnostic plug in the engine bay. Tried an ae92 MAP sensor on it, no difference. Found out that one of my plugs had been ripped off by the pod filter, soldered that back together and still having the problem. No boost leaks or vacuum leaks as far as I can tell. Got it booked in on Wednesday for a thorough going over so that should sort it out.

[TERRA Operative]

Hopefully that damaged plug didn't damage the ECU....

[boon280]

might sound like a basic thing to do but I have had similar problems with silvertop occasionaly and I swap the ecu over (i have several) and it will run fine.
I have swapped them back later and the original one works perfectly, you may need to just unplug it and let it sit for a while.
You may have bigger problems but it could be worth a try.

[Mitchee]

might sound like a basic thing to do but I have had similar problems with silvertop occasionaly and I swap the ecu over (i have several) and it will run fine.
I have swapped them back later and the original one works perfectly, you may need to just unplug it and let it sit for a while.
You may have bigger problems but it could be worth a try.

This is true.

My AE101 GZE did exactly what was described in the first post. And doing exactly as above fixed my problem. I now carry 2 ECUs with me incase one has a hiccup. Swapping them over seems to fix the problem instantly.

[boon280]

Yeah I went racing the other weeekend and the thing had a fit on me and it would only go at about half the power it usually has, so I unplugged it and let it sit for a while then plugged it back in warmed it up to operating temp then switched the ignition off for about a minute ( apparently they need to reset after being plugged back in) and away it went, no problems.

[TERRA Operative]

Disconnecting the battery for a minute or so will perform a hard reset on the ECU too.

[TERRA Operative]

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[Intense]

turns out the ecu has fried a few capacitors. Seems to be a problem on only the jz and 4agze ecu's

[TERRA Operative]

Check out the AE101 link in my sig for a complete rundown on how to replace the caps and what parts to get.

[Intense]

Here's the guts of it

Found another ecu I'm going to get and then we'll fix this one up

[Lambolica]

Funny that, My mother in law has been complaining that her car has no pick up (as does the rest of the family) I had never been (allowed) to drive it. but last week She lent it to me to get to work, I drove probably 500m when I worked out that the auto was stuck in 3rd gear.

Cut a long story short, after some searching on the net, with that particular model Galant the capacitors in the ECU's were very prone to leaking and melting and failing. In fact most capacitors made in the mid 80's to about 93 that alot of auto manufactures use (including toyota/lexus) are prone.

After reading this I went home and pulled apart a 1G computer that was problematic and sure enough there is a burn cap in there as well.

Just coincidental that this thread popped up.

Oh and my mother in law has been driving with the auto in limp mode for over 4 years?!?

Cheers
Simon

[TERRA Operative]

Yea, that one's a bad one Intense. You should look at cleaning the tracks and maybe soldering in wire jumpers if they're really stuffed.

[Intense]

Bought another ecu for 70 bucks. Will fix this one up and sell it after thorough testing