joscorstjens
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| posted on 2/8/07 at 01:30 PM |
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pinto idling rough
Hi,
the exhaust pipe of cylinder 4 of my injected pinto is blue-ish, while the other 3 exhaust pipe are rather yellow-ish. Is this what can be expected on
a pinto?
All spark-plugs have a black soot, is that what I should expect?
I'm asking the questions because the engine idles a bit rough and when giving a dot of acceleration, there is initially some hesitation but only
after 2000 rpm, the engine runs well. When releasing the accelerator pedal, the egine has difficulties not to stall. I checked for air-leaks and when
disconnecting the IAC valve, the engine will stall immediately, so I think the IAC works (at least to some extent). Any suggestions for further
investigation or tests will be appreciated!
tia
jos
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BenB
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| posted on 2/8/07 at 01:41 PM |
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Sooty plugs means the car is running rich.
The blue exhaust is getting hotter than the others (you can even use an IR pyrometer to prove it), probably meaning its not running as rich as the
other cylinders.... (the excess fuel cools the exhaust)...
I'd use a Colortune (but then I always say that...) to look at the different mixtures for the cylinders...
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DarrenW
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| posted on 2/8/07 at 01:56 PM |
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Mark Allanson is the only other person i can think of who is running the pinto injection system. As above - sounds like its rich and maybe not set up
correctly but i dont know what adjustment options you have.
Would plug type have anything to do with it?
Could it be sucking in air near to one of the cylinders?
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BenB
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| posted on 2/8/07 at 02:14 PM |
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Does the Pinto system get as complicated as Lambda sensors?
If so, wouldn't an airleak on the blue cylinder (at the exhaust manifold) upset the lambda and make the rest run rich???
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phoenix70
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| posted on 2/8/07 at 03:12 PM |
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Black soot on the spark plugs would suggest it is running rich, and the stuttering accel would also point to that.
No a lot you can do to adjust the mixture on the car, but I believe there is a mixture screw on the airflow metre that may help, but maybe the airflow
meter is faulty.
[Edited on 2/8/07 by phoenix70]
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jollygreengiant
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| posted on 2/8/07 at 03:40 PM |
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The pinto has NO lambda sensor.
All injectors are effected equally by any adjustment.
There are only limited items that might/would give this effect on one cylinder.
Valve clearances incorrect on one cylinder and the mixture incorrectly set.
An air leak on the inlet manifold gasket on the one cylinder. However this would tend to affect all cylinders due to common plenum and inlet
tracts.
An air leak on the injector into the manifold around the 'O' ring.
A blocked or fault injector. Would need an oscilloscope or an injector test rig to be sure. (could try swapping the injectors around to see if the
misfire moves)
A limited short across the terminals of the injector plug (receiving low voltage thereby short on injection pulse), but this is unlikely.
There are only very limited adjustments that can be made to the fueling on the EFI, timing , idle speed and mixture.
I have found that it is best NOT to play with the base idle setting. Once set by the factory it should NEVER need adjusting.
Timing is normally set to about 8deg BTDC.
I covered re-adjusting the emission on a pinto injection in a previous post so here it is again.
link to pinto Efi adjustment
I hope all the above helps.
Oh & I'm doing a pinto injection Viento. Got it fired up the other day for the first time, no exhaust. SWEET.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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BenB
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| posted on 2/8/07 at 03:58 PM |
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I wondered if Lambdas were too cutting edge 
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joscorstjens
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| posted on 2/8/07 at 11:16 PM |
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All, thanks for the inputs, I'll check them all tomorrow. Still, I have two questions:
1) On rich mixture: the measured CO-values were quite ok for SVA requirements so I'm not sure about that (on the other hand: the smell seems to
suggest some 'richness'?
2) All spark plugs are equally sooted while only one exhaust seems to have the right colour (heat)?
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jollygreengiant
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| posted on 3/8/07 at 04:08 AM |
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It could merely be down to valve clearances and condition of valve seats. 1 cylinder running right AND the other three not quite due to clearances
and/or seat condition.
quote:
Originally posted by joscorstjens
All, thanks for the inputs, I'll check them all tomorrow. Still, I have two questions:
1) On rich mixture: the measured CO-values were quite ok for SVA requirements so I'm not sure about that (on the other hand: the smell seems to
suggest some 'richness'?
2) All spark plugs are equally sooted while only one exhaust seems to have the right colour (heat)?
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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