The 75 and ZT Owners Club Forums - Reduced fuel consumption and smoke

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Reduced fuel consumption and smoke - 2004 Diesel

I guess your title should read INCREASED fuel consumption.---;)

You seem to have done some thorough maintenance. About the only thing I can think of is an injector problem.

If the spray pattern is poor your fuel consumption will increase due to the incomplete burn and there will be smoke from the exhaust.

Your injector cleaner might not have done a good enough clean up.

This of course will give less mpg.

Have you cleaned the Map sensor or the inlet manifold? Artic advised me when my car failed the mot that it could be the map sensor. It evidently sends a signal to the ecu about fuelling amounts, by way of reading the pressure in the manifold.

What's the running temperature?

TC

Quote:

Originally Posted by JMW (Post 2719871)

Runs at normal temperature

Have you checked the actual temperature?

TC

Sounds like an leak in the intake system - perhaps a leak in the intercooler?

Quote:

Originally Posted by JMW (Post 2720020)

Is there any way to check this or will I need to remove the inter cooler and inspect it?

If you are 100% sure of the rest of the intake pipework and can find no other explanation I'd examine the possibility of the intercooler leaking. I expect some stripdown of the front end would be necessary to get at it for inspection if you've no other way of testing it.

Jonathan,
I’ve sent you a pm, but in case you haven’t seen it, perhaps take a look at my other thread.
Diesel intercooler query
https://r.tapatalk.com/shareLink?sha...3&share_type=t

Look to see if you can see any oily deposits on your intercooler.

Sent from my iPhone using Tapatalk

Yes the map sensor was really blocked up. Artic you have to thank for that advice. I passed it on to you from his advic to me when I was having problems with emissions from the mot test.

Quote:

Originally Posted by JMW (Post 2721725)

This morning I decided to swap over the MAP sensors and the cleaned manifold that I got from a 75, I was expecting to see some really bunged up areas however the manifold and the egr were quite good, the MAP sensor was however blocked.

I cleaned out the EGR, replaced the MAP sensor and did a few other little jobs I’ve been meaning to do.

Quote:

I couldn’t replace the manifold in the end as one of the bolts and bolt surround was missing. The intercooler pipes all look ok and have already been replaced.

Once all back together there is a big improvement, little smoke and runs fine, just driven 112 motorway miles and returned 46 mpg which is better than I was getting before. Doesn’t feel particularly lively so might do some more research on the 160 re map.

Pic of the MAP sensor from the 75 replacement unit.

Thanks to everyone for the help in getting this sorted.

HI Jonathan
The bolts and there surrounds can be taken from the manifold you would take from your car and added to your cleaned out replacement manifold, so do not worry about changing it over go for it the car will benefit from it ;) Arctic.