7MGTE miss. >update, all fixed

**boxh34d** · 24-06-2006, 07:27 PM

Thanks to all that have replies so far.
As i have no garage at the moment, and i havent been home in daylight hours, i havent been able to check.
But, on the heat rating on the plug issue, i went for a drive tonight and gave it some squirt when it was just below full temp, and funnily enough, i couldnt feel it stuttering.
Tomorrow shall see some results hopefully.

**boxh34d** · 01-07-2006, 06:45 PM

Ok, update.
On Thursday I ripped the plugs out, checked the gap, and I could land a light plane between the tip and ground electrode. Some where around 1.1mm, but varied, one up to 1.4mm!!!! Got to love mechanics presumptions

I gapped them down to .8mm, put it all back together, and took it for a drive. I wasn't giving it hell, but it seemed to cure the problem.
Tonight I went for a bit of a drive, and it all still seemed well, until after about 15 mins of testing, it started to drop one cylinder again. And i mean completely drop one, not just cough and fart.
So, my question is, what spark plug heat range and gap are other people using??
Is there any other reason it would only start doing it after a given period of time??? Coils getting too hot and not working properly etc etc???
Thanks.

**boxh34d** · 14-07-2006, 05:29 PM

Ok well, after doing some looking around, it turns out that the whole problem was caused by a combination of things.
One problem was that the wastegate actuator arm was sticky, so it was spiking and then diving with boost. Once freed up, boost is more stable, and fueling more smooth.
The engine was still running pig rich though. Turns out that the thermostat was stuck open, and telling the ECU to dump in fuel, which was causing the fouled plugs to break down intermittently.
The whole problem was very hard to track down because when testing, no two times were the same.

Before someone asks, yes, I had noticed the fact that it did take a while to warm up ( not ages, but a while ), but not owning the car before this was occurring, I didnt know any better, and didnt really think much of it. Also, some other cars that I had driven would never warm up with no thermostat, so it never really entered my mind to check that part.

All in all, after problems solved, it is still running a bit rich in the top end, but I guess I am to expect that from an 80's turbo car. Good news is, it is making much better power, and is smoother and more tractable.
The final figure was 190 RWHP, or close enough to 140 RWKW.
I assume this is about normal for a car with no mods save for a cat back exhaust??

A big thank you to all who had replied previously, it is much appreciated.

Reps have been distributed.