I'm not sure exactly where the PTU is (or exactly what it does) but from searching through the forums it appears to be a trouble maker. My 300 is missing at low revs (up to about 2.5) but smooths out at higher revs and seems to run ok. If I floor it at high revs, no problem. Down low and it sounds like poo, like it's missing on one of the cylinders or running really rich.

I took off the coil packs on 3 of the cylinders (one at a time) and fitted a spare plug. All three of them seem to fire ok but miss every 8 or 10 or 6 sparks. Any ideas...? (the other 3 coil packs are under too much stuff for my limited skills...I think)

 

BTW, this started happening AFTER I got my 100,000km service. Shit.

 

 

Thanks :)

This doesn't sound like the PTU to me.

 

How is your wiring to the injectors?

As far as I know it's good. The guys that did my service replaced all the connectors because they were broken and dodgy. Apparently one of them was taped together!

The wires themselves though...?

And you are confident that they have done a proper job on the connectors?

 

When I said the wiring I meant the wiring/connectors.

 

Can you lay your hands on a spare PTU just to make sure?

 

Have a little read through this maybe for a few pointers.....

http://www.twinturbo.net/ttnetfaq/FAQpages/hesitate2.html

Ive got exactly the same and my problem is the injector wiring. Easily fixed buy buying http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=24079-00002

Have a little read through this maybe for a few pointers.....

 

Didn't like the bit abou the heads on the 1990 model, that's what i've got :(

 

I'll try the cleaning though, sounds good. Did I mention that the first few minutes when I start it up it runs ok? I wont be able to get a PTU without paying for it though :(

 

Perhaps I should go to a good auto electrician and get the thing re wired?

 

Chris,

Ive got exactly the same and my problem is the injector wiring. Easily fixed buy buying http://www.courtesyparts.com/Mercha...ode=24079-00002

I don't know if I could fit that by myself or if a sparkie would do it for me. Would I need to buy 2 lots? It says 3 pack...

Yup buy 2 packs of 3, for the money you may as well just do it anyway ;)

Hi,

 

I don't think it's your PTU cos it wouldn't rev properly past 2.5K, it would splutter. Make sure your coilpack connectors are fully pushed down. I had exactly the same symptom a while back and it was one of my connectors not all the way on (only slightly).

 

Vijay

Observe the exact same symptoms often in the workshop, usually tps will be showing a closed idle switch even with an open throttle, after 2,500rpm (ish) this usually open`s and allows the ecu to fuel/timing to be correct. As a warning often the tps linear reading will be close to normal so will not show as a fault on an ecu check, needs a ConZult or meter check on the hard idle to confirm this.

 

Jeff

Hey Jeff, that sounds like a good suggestion. Is the tps easily cleaned/fixed and :confused: where is it...?