Jim.

Yes, as Trent says.

Ok Dave, it is very punctilious of you to post all the above details for the reader. That is all good reference stuff, however we are not the ones experiencing the problem. I still don't know why you seem to want to interfere with the wiring harness and ECU connectors. If there is no visible damage to insulation, I don't see a reason to replace the wiring runs. Maybe I have missed something here? Did you read my post # 34? Jim.

Thanks for that comprehensive report Sploddy. Yes, you have clarified the yellow and black wire question well enough. While driving around town today in my car, I had a bit of an epiphany. If either injector #1 or #3 has a partial or intermittent short circuit, that would cause the output transistors driving them to fail. I'm assuming the injectors consist of kind of solenoid device, with a coil and armature etc. If the coil is shorting between turns, this would cause a low impedance and could create the problem. A couple of injectors second hand would probably be cheap. I would either have them checked thoroughly, or simply replace them and try it out. As for the wires referred to above, if the wiring was visually inspected and found to be in good order as you report, I doubt if there could be any other problem with them. After all, one of them would have to short to chassis (earth) to blow the output transistors. Jim.

Thanks for your decision to continue communicating with us. Also, the details of suppliers etc. above could be useful sometime in the future. I'm a bit puzzled by this part of your installation instructions: ................................. The mechanic at the wreckers strongly recommended not using the original cabling (yellow and white wire) but to cut them close to the plug and patch in at the cut wire and run a separate pair. He said the ECU came off a fully operational engine and therefore taking this precaution it should work. eliminating any intermittent shorts in the harness. The unused wire ends should be heat shrinked to prevent shorting anything at either end and tied back with a cable tie. ...................................................... What cabling is this? My ECU is simply plugged in with a couple of large multi-cable couplers. No cutting of wires necessary to change it. I agree with what Trent has said however. After all, the exact same fault developed with both the original ECU and the second one that replaced it. The fault is clearly external to the ECU. It's good though that you have the necessary skill and experience to repair your damaged ECU; this might save you a lot of money. What you have written about it reveals a couple of potential problems that older units might develop and how to fault find them and fix them. I'll cut and paste your report for future possible reference. Jim.

That is great news Ladidi! I'm glad you were able to negotiate some of the bill. My understanding is that this vehicle has the OBD1 (On Board Diagnostic 1) system. This means that the ECU codes can be read without a code reader by following the instructions in the manual. It involves shorting out two of the terminal in the diagnostics socket under the bonnet. All described in this short video here: I got caught out myself and paid for an auto electrician who also could find the codes on my former vehicle (5SFE engine) some years ago. I've since discovered the above. Anyway, happy motoring to you. I agree with you about the car; I have a 1993 manual trans wagon which I love.

Any updates Ladidi?

I thought it would be. My earlier one is a 5SFE as I have said. Have another look on the compliance plate. I know I mentioned rats before. But has there ever been evidence of rats in the engine bay?

My first thought after reading the posts so far, is to check the alternator output voltage like Trent suggests. If it is overcharging, that can blow power transistors. However, it is still a curious fact that # 1 & 3 have failed for the second time. This would indicate a wiring fault. Rats can eat through wires and I have to keep rodent poison up to my engine bay to keep them under control. If some insulation is eaten away from a wire, it could short out to chassis intermittently. A simple multimeter check will not reveal this, as you will know, and a visual check of the harness/loom would be required to eliminate this possibility. Physically challenging task due to accessibility problems. I'm now glad I have a spare ECU for my 5SFE 1993 Camry! edit: Is your model engine a 5SFE?

Is your guage an analogue one or digital? If analogue, the tests are simple and can be found on a DIY site on the net. Or I can describe if you want.

"loan of some spring"??

Yes, I would ask for a written report as has been suggested above. Also, I would take a print out of what Trent has documented for you above to the mechanic and ask if the codes were read and what the results were. If they were not read, I would be a bit more inclined towards your position regards not paying or not paying the total billed amount. All the above being satisfied and answered, I suspect you will have to pay as has been said.

How long since the fuel filter has been replaced? This is a periodic service item (50,00 klms or so?). If it has not been changed for some time, it would be a good idea to change it anyway. It is a remote possibility, but could be the problem.

Where have you gone Chris?

Where have you gone Dan? I've logged on each day only to find you have not replied for four days. I would like to see you resolve this and get it fixed. Here is the test procedure for an analogue type guage: http://www.ehow.com/how_5908457_test-fuel-gauge-see-working.html

I got 410,000 klms out of my last auto trans Camry. Only took it off the road due to a failed trans for the second time. It would cost more to fix than the value of the vehicle. I much prefer this one which is manual. Approx 25% improvement in fuel economy and power.

Yes, that's a possibility Trent.

Thanks Malaus. I'm beginning to form the same conclusion. How many kilometers had your 93 Camry done when you sold it? Manual trans or auto?

That's good news. There are several descriptions of the simple tests that can be done with analogue fuel guages. I did some recently. Also, the needle on that type of guage is usually a press fit onto the spindle. At least mine is; I only just worked on it a short while ago while fitting a tacho to the dash. What this means is that the needle can be pulled off and replaced onto the spindle in another position. Fit, test using test procedures above. If you can't find the description(s) quickly, let us know and I find them for you.

For the older analogue types, the test prodedure is described in various published links online. Also in my electronic service manual (for earlier vehicles). I'm guessing yours is a digital one? I would do a search online for a test procedure in that case, unless you already have a service manual for it.

Is this guage an analogue one or digital?

Chris, The only voltage regulator in the vehicle that I am aware of is the alternator voltage regulator. Everything else is 12 volt. Unless of course, the computer has a 5 volt regulator in it. However, if that was the case and it was faulty, it would go open or short circuit and blow the computer or shut it down. Either way, the car would not run. Your last post would have me checking the chassis earths under the dashboard. They are not too hard to dismantle, at least my generation 2 Camry isn't. I'm currently wrecking one, so will have a look under the dash of that one to see if there is anything I can possibly lead you to. I've just had a look at the engine bay earth straps on mine. If there was a small brake fluid leak while filling some time long ago, it could cause corrosion around the bolt that fastens the two black straps I mentioned (or any of them). I would undo them, rough sand up the body panel to bare metal and the lug and bolt; replace, tighten and then paint for future protection. The wiring diagrams don't show these earth straps, which on reflection, makes sense. They don't connect any discrete components to any others, so to speak. Don't give up!

There will be two or more on the Engine block to start with. I will have a look on the wiring diagrams for that model later on and see if they are listed. On my 5SFE engine, there is one black strap with a plug and socket that runs over the engine stabiliser mount behind the alternator for example. I would check both ends for any corrosion and also disconnect the plug and sockets and give a shot of cleaner such as WD40 etc. before connecting again. Do you have access to wiring diagrams for that model? My electronic service manual(s) are listed by year model. So post your model details here, and I'll have a look at the diagrams I have to see what I can find. With some perserverance, we might be able to find them all and then you could service them all.

Thanks for the correction Trent. OldMechanic. Yes I know the frustration of chasing intermittent electronic faults. I can't help but suspect one or more of the earth strap joiner clips. I think I would clean and service each of them with CRC or WD40. Do you have access to the wiring diagrams?