Tuesday, September 30, 2008 - 10:44 pm, by: David Barry(Davidb2008)
Hi everyone, I've got a problem with my 1992 UZZ31 Soarer. It idles ok not perfectly but acceptably. When I rev the engine it struggles has no power and runs roughly. At around 1500 revs or so the tachometer display goes blank and it occasionally flashes the correct reading. I have also noticed a strong smell of unburnt fuel coming from the exhaust.
I have just replaced the spark plug leads and I have also tried the same test while running on LPG with the same results which I assume rules out a faulty fuel pump and fuel pump ecu. I have also run the engine ECU diagnostics but have not been able to get any error codes out of it. After I run the test, no lights are flashing and the lcd display on the speedo says "ECU Ok". The oxygen sensors were new about six months ago.
The problem came about while I was driving and the engine backfired and blew apart the pipe from the airflow meter to the intake manifold. This is a common problem with lpg converted engines and is often the result of an ignition problem. This is why I replaced the spark plug leads. After the backfire I was only a short distance from home (about 2km) so I switched back to petrol and limped back. On the way back the catalytic convertor warning light switched so I stopped and waited for them to cool down. I then drove the last bit back home. After this I replaced the damaged pipe and replaced the spark plug leads to try and stop it happening again. This is when I discovered the problems I described above. Has anybody got any suggestions on what to look at next? I'd also be interested in any recommendations of mechanics in Footscray or anywhere in Melbourne’s inner west who have experience with soarers.
Wednesday, October 01, 2008 - 04:51 pm, by: David Barry(Davidb2008)
Thanks everybody who replied. I've disconnected the airflow meter and found that it runs exactly the same without it so it looks like I will need a new airflow meter. Is this likely to be the cause of the tachometer problem too?
Andrew Ferres DieHard WA '90 C-F Celsior V8, '84 Soarer V8, '91 Supra V8
Thursday, October 02, 2008 - 09:44 pm, by: David Barry(Davidb2008)
I've swapped the two igniters around and tried again and found that the tacho is still not working correctly. After this I tried disconnecting each of the coils and seeing if it runs any differently. When I disconnected the top coil the engine would not start at all and when cranked did not show any sign of running. I then tried this with the igniters swapped around and found no difference.
After this I tried the same test but with the lower coil disconnected and found that while the engine would not run when started it definitely showed signs of ignition and trying to start.
I also measured the resistance of both the coils and found that the top coil had a resistance of around 2 ohms on the low voltage side and 12k on the high voltage side. On the lower coil I found that the low voltage resistance was 2 ohms but the high voltage resistance was only 9k which is quite a bit lower than the 12k which is supposed to be normal. Does it look like I need a new coil or is there something else I should be looking at?
Andrew Ferres DieHard WA '90 C-F Celsior V8, '84 Soarer V8, '91 Supra V8
Awesome this post saved me a lot of time hunting for what the cause was. Thanks!
Symptoms: - Running on 4 cylinders (ie big loss of power) - Tacho flashes to zero (esp once over 1000rpm) - Smell of petrol from exhaust - Alternator error/warning (not charging battery)
To troubleshoot (if you suspect coil): - Take plug off lower coil (passenger side one). With the high voltage one (thick one should be pryed off with screw driver) unplugged only then it should exhibit the same symptoms. With the low voltage one unplugged my car would not start. - Proceed to measure the resistance of the coils. They should be within the recommended guides as per: http://soarercentral.com/sc-forum/messages/282/40635.html - If coil measures OK you could swap the igniters as a test.
I immediately swapped the coil off my second soarer as a test (after seeing this post with same symptoms) and it fixed it straight away, while my other soarer began to exhibit the same behavior with the busted coil. So that confirmed the diagnosis.
Part number for replacement coil from Toyota is: 90919-02197
Thursday, December 27, 2012 - 04:01 pm, by: Paul Morante(Breaker)
I also wish to thank this post, and the many other posts that I have read since my similar symptoms. Mine started two weeks ago with a slight miss at start up, but disappeared as the temperature rose. Thought it must be one of the original h.t. Leads, so performed an ohms check, and inspected the 60,000 k iridium. All looked ok, but next morning limp mode set in. Performed all the normal diagnostics resulting in no direction of attack. Finally removed the lower coil to find a crack across the full width of the resin face, which was hidden with fan grime. Purchased and fitted a Camry coil which has the same shape, mounting holes and input terminals, but the output terminal was oversize, so fitted a spring loaded brass ferrule to compensate! Fired up like new. Also now know that the igniters and ECU are healthy.