Engine has started cutting out

[Badwolf]

Hi All
Have started having issues with my early 1uzfe cutting out,
For context i have an early 1UZ engine fitted in my MK4 Supra, which has a Soarer engine wiring loom and standard ECU, this is a straight forward plug and play setup.

The engine has started to randomly cut out usually at the most inconvenient times but usually when at running temperature. So far i have managed to get it back home after cutting out but only after an hour or so.
I have been to several garages with diagnostic machines to get a fault code but have been told that due to engine swop they can not diagnose the problem on there machines.
I bought my own hand held diagnostic machine but have not been able to get it to talk to the ECR.
I purchased a second hand duplicate ECU, which i fitted but am still having the engine cut out. Before it cuts out the engine management light comes on along with the handbrake light.

Any ideas what could be causing this issue or have any recommendations of any services around the Wiltshire area who may be able to help with diagnosing the issue?

 

[P Bateman]

"The engine is cutting out" is a very broad statement, as there are literally dozens of reasons why an engine will cut out - and diagnosis is a process of elimination, working through each potential cause to confirm whether it is (or isn't) the cause. If the fault has been detected by the ECU, it will have stored the fault in its memory, however you don't need a scantool for this... just a short piece of spare wire. This is not rocket science and you will save yourself shitloads on labour costs.


If the person who did the engine conversion is awesome, you should have a malfunction indicator lamp (MIL) on your dashboard:

1. Switch the ignition on - but do not start the engine
2. Locate the either diagnostic link connector #1 or #2
3. Using a split pin or spare wire, bridge the terminals TE1 and E1. This will put the ECU into inspection mode
4. Record the blinking sequences (codes) of the MIL. It will end up repeating
5. Compare the codes shown to a troubleshooting guide or just post them here and someone will tell you what they mean.

But, if the person who did the engine conversion was a bit sketchy, you won't have a MIL, so grab yourself a test lamp.

1. Follow steps 1 to 3 as shown above
2. Using your test lamp, connect the alligator clamp to 12v+ battery power
3. Gently hold the probe end onto the W terminal of the DLC#2 plug (shown above in blue)
4. Record the blinking sequences (codes) of the MIL. It will end up repeating.
5. Compare the codes shown to a troubleshooting guide or just post them here and someone will tell you what they mean.

Now, if the person who wired up the car is a complete dogarse, you may be missing one or both of the DLC connectors. If this is the case, you will need to (carefully) perform the TE1 to E1 pin bridging and W terminal probe on the back of the ECU.





Having said all of this, if the fault is something that the ECU cannot detect (i.e fuel pressure or ignition lead failure) then all of the above has been a complete waste of time and it will need to be diagnosed it the old-fashioned way. Combustion will only occur when you have compression, fuel and spark and, given that compression doesn't intermittently drop out on a running engine, its likely to be either fuel or spark related. No amount of fancy scantools in the Wiltshire area will find this problem and they will need to rely on their ability to interpret the first sentence in my post.

Depending on how handy you are with spanners, google "soarer bible" and get cracking on the Engine Troubleshooting section. Page EG-484 is a good place to start. The fact your engine is cutting out when everything is hot is an important factor. Vapour lock in the fuel system is temp related. Coils, leads or igniters can fail when they get too hot, as can camshaft or crank angle sensors. An cooked air flow meter that too close the exhaust heat can get cooked. The list goes on.

 

[Badwolf]

Many thanks for the pointers, will look at trying the second step over the weekend as their is no MIL fitted and if no success go for the soarer bible, again thanks for reply.