excessive exhaust fumes...SOLVED.

fiatmonkey

fiatmonkey

Tim Hoover
I have noticed ever since I did the cam box repair an excessive amount of exhaust fumes. Someone told me I smelled like "Jet fuel" this morning at the coffee shop :( I also had put off fine tuning my timing until this afternoon so I thought it was related. However I got the timing set (although the idle is a tad rough). No change in exhaust smell.

Any thoughts what it might be? The car IS running a "test" pipe so a lack of cat already puts me in the pollution ring however even when I removed the cat it never was this bad.

I double and tripple checked my timing and everything is dead-on mark wise.

I don't really know how to resolve this and driving the car is not fun right now the way it is...


:: UPDATE ::

I had suspected the issue was a result of the recent work I did (swapped cam box, valve shim adjustment, etc).

So I dove into the car and started with re-adjusting the valve shims. I found that one intake was WAY to small clearance so adjusted that along with a few others that needed re-adjusting. Weather wasn't cooperating and of course co-xweber Bill Abler gave a visit so I closed up shop and took a nice coffee break.

When the weather cleared enough today I decided to go back and confirm/adjust my timing. Sure enough I was out both cam and ignition.

Got everything adjusted and the car running smooth. And wouldn't you know it; exhaust fumes diminished quite a bit. Almost back to "stock" odor :)

Thanks for the help and posts. I still might might be buying some frangrance additives: http://www.palmerracingfuels.com/additives.htm

:)
 
Last edited:
wannabfast said:
if you run premium it will smell like race fuel with a test pipe, did your tappets move spots?
Click to expand...


What do you mean by "did your tappets move spots?" Do you mean did I switch them around? I had to completlely re-adjust the valve shims since I ended up milling the cam box 1.00mm so all new shims.
And I do run premium - 91 octane here.

-Tim
 
!

This is a tough one to diagnose without more info.

Is the smell so bad because it's leaking into the cabin? Or is it that the engine is actually making more smell? How many miles have you put on the car since the rebuild?

1. The test tube may have the paint burning off.
2. You may have vac tubes in the wrong place throwing off the fuel ratio.
3. The crankcase ventlator isn't connected, venting bypass vapors all over the place.
4. The engine is running better and burning off old oil deposits in the exhaust.

How many miles are on the repair?
 
Good questions:

Is the smell so bad because it's leaking into the cabin? Or is it that the engine is actually making more smell?

It will creap into thru the winows some. Today was really warm so I had the top off and thus even more fumes into the cabin.


1. The test tube may have the paint burning off.
Its been on the car for a year so its not the issue (I dont think)
2. You may have vac tubes in the wrong place throwing off the fuel ratio.
It's possible though I kept track of the setup its possible its been wrong all the whole time.
3. The crankcase ventlator isn't connected, venting bypass vapors all over the place.
Its connected.
4. The engine is running better and burning off old oil deposits in the exhaust.
hmm...I guess that is possible.
How many miles are on the repair?

Less than 400.
 
!

In the auto repair world in general, sometimes when you fix one system, another system will fail. And many times, when you repair valves you actually end up burning more oil. Having better valves forces the rings to work harder. So it's possible that you are burning more oil than before. I hate to suggest the worst, but you may need rings.

Check your spark plugs for signs of burning oil.

It's also possible that getting the valves fixed has thrown off the fuel mixture and it just needs to be adjusted. However, typically adding a test pipe LEANS the mixture. It's near impossible to get the stock fuel injection to run very rich. Again, check the spark plugs for signs of running rich.

Finally, a weak spark or bad plug wires would lead to lots of unburnt fuel passing out the exhaust. That would smell like fuel. So again, check you spark for a strong blue spark.

Or you caould just always drive very fast so the exhaust fumes would never catch you!
 
First off, having the catalytic converter off of the car will cause it to smell much more. Secondly tuning it for performance by tweaking it is likely to run much richer and cause the engine to expel much more unburned hydrocarbons.

We have all gotten used to cars not spewing out lots of noxious chemicals so it is no surprise that when it is returned to 1960s levels of pollution people will notice.

My 1969 850 Sport Coupe smells really bad compared to my newer cars. My wife followed me home last summer and was really taken back by the exhaust smell from that little engine.
 
I'm with Karl on this.....

Additionally, the fuel these days has a *lot* of chemicals in it to adjust the properties. Much more so than in the days before catalytic converters. When they took the tetraethyl lead out, a bunch of bad smelling other stuff went in.

Ciao,
 
Tony the incredible

Tony your incredible! :confuse2: I never think a product like this can exist!
You find it!
I lift my hat! :worship:
 
It is rather unbelieveable...

I've been to a few car shows and seen some really radical full blown rods go cruising by, THUMPING AND POPPING and through all the noise... this sweet smell of cinnamon floats through the air.... HA!

Crazy!
 
Kinda expensive Tim... but probably worth the effort!

Especially waiting in line to pick up your daughter from school!

You'll be the talk of the classroom!

HA!
 
Really amazing stuff Larry...

... let us know what flavor you choose!

OH... BTW... I have NO idea if it works or how it works through a catalytic converter. Ya might wanna call and ask first. I don't believe any of the cars I've ever seen (smelled) that used this stuff were running cats!
 
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