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> WHITE EXHAUST............., After warming for 60+ seconds, starts to run very rich, exhaust turns white
ctc911ctc
post Sep 19 2018, 01:52 PM
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From: boston
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To all ECU/MPS/TS2 people!

I have a '74 2.0L that I am resurrecting to be original equipment with the exception of all of the Hell-Hole parts which are Rest-Design or other vendors.  The problem that I have been admiring for 2-3 weeks is one of White Smoke, or richness that begins after the engine has been running for 1-2 minutes.

Background: ’74 2.0 barn find, 20K miles all indications are this is accurate (brake pedal wear, rotor wear, seat wear, all other used car tricks, etc….)
Replaced fuel system tank to injectors
Replaced all vacuum hoses
Replaced all other fluids
Replaced Hell hole, longitudinal, floor pans.
Body – perfect, really, really good.
Engine started, sounds like a swiss watch – no mechanically ‘noise’ just mechanical music….
A little rough, however – too much engine motion in the bay

As the engine warms, the injectors are told to put way too much fuel into the system, white smoke and rich exhaust smell start after 40-60 seconds of operation.

Here is what else I did so as to learn as much as possible about the process. I bought a second MPS from a 911World - great guy, very engaged and supportive (THANKS!). I also bought an ECU from him. When I received them, both checked out as ’74 2.0 numbers. Great, though the new MPS is a bit leaky, it compares to the numbers of the one I had which I replaced the diaphragm

I put the two MPS units (the one I  got with the car and the one I bought) on the bench and here are the numbers - very similar - My H meter is not calibrated so I believe since the two are VERY similar that I have a calibration problem…

 Setting____Reference__New Diaphragm___Purchased though leaky
0 inHg._____1.45_______1.06______________1.15  
4 inHg--------1.24_______ .94_______________ .96  
15 inHg______.75_______.66_______________ .66  
 
1. I have tried both MPS units – operates the same, white smoke starts after a minute or two.
2. I Swapped the ECU units – operates the same, white smoke starts after a minute or two.
3. Replace the TS2 with a rheostat (variable resistor) tried it at 1K/500/300 - I believe it changed the time before the white smoke….takes a bit longer, have not timed this effect yet.

I have not done anything with TS1 (Air temp sensor) since it has a marginal effect on mixture (see https://members.rennlist.com/pbanders/ecu.htm Common Questions)

Talked to the guy who rebuilt the injectors and he has never seen a stuck injector which would stop being stuck when the car is off. (The fuel rail holds 30lbs for hours so injectors close when off).

I am centering the MPS/ECU/TS2 part of this equation.

Will keep digging, ANY advice would be very welcome!
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Posts in this topic
ctc911ctc   WHITE EXHAUST.............   Sep 19 2018, 01:52 PM
ndfrigi   is the smoke coming out of the tail pipe? if yes, ...   Sep 19 2018, 02:09 PM
ctc911ctc   Smoke is white, passes the paper test (white paper...   Sep 19 2018, 02:28 PM
cuddy_k   White smoke is usually from water or antifreeze. A...   Sep 19 2018, 03:26 PM
TheCabinetmaker   When the heck did white smoke equal running rich?...   Sep 19 2018, 04:13 PM
ctc911ctc   Thank you for the reply, what part of the ignition...   Sep 19 2018, 05:22 PM
JeffBowlsby   You may not be aware that the Anders reference MPS...   Sep 19 2018, 04:24 PM
ctc911ctc   Jeff, Thank you for the reply, 1. I believe tho...   Sep 19 2018, 05:19 PM
JeffBowlsby   Jeff, Thank you for the reply, 1. I believe th...   Sep 19 2018, 07:44 PM
TheCabinetmaker   Whoa! A mechanic rebuilt the injectors? Your f...   Sep 19 2018, 06:08 PM
ctc911ctc   Bosch Guy, German - Hurst Injectors. Has a calibra...   Sep 19 2018, 08:35 PM
bandjoey   Clay just posted that front transmission seal went...   Sep 19 2018, 06:13 PM
Chris914n6   the cold start valve would close after 1-2 minutes...   Sep 19 2018, 06:15 PM
TheCabinetmaker   the cold start valve would close after 1-2 minute...   Sep 20 2018, 07:54 PM
ctc911ctc   UPDATE - tested various items, no change. Cylinder...   Sep 20 2018, 05:57 PM
nditiz1   How cool is it where you are? Does it smoke after...   Sep 21 2018, 05:27 AM
ctc911ctc   It was in the 60's when I took the vid, the ca...   Sep 21 2018, 08:03 AM
ChrisFoley   First time I started the car all of that (includ...   Sep 21 2018, 09:01 AM
cuddy_k   Sure looks like oil smoke. Does it smell?   Sep 20 2018, 06:57 PM
ctc911ctc   After I posted the video I realized that the car i...   Sep 21 2018, 07:59 AM
ChrisFoley   Does the idle change when it starts smoking? The i...   Sep 21 2018, 05:48 AM
ctc911ctc   Tangerine Chris, Great to hear from you in this t...   Sep 21 2018, 08:07 AM
ChrisFoley   Yes, a few seconds from the smoke starting there...   Sep 21 2018, 09:03 AM
naro914   Looks like oil smoke to me. does it ever go away? ...   Sep 21 2018, 07:41 AM
Jonathan Livesay   Simple test for auxiliary air valve, pull the hose...   Sep 21 2018, 10:31 AM
ctc911ctc   UPDATE Today I changed the plugs with new ones. H...   Sep 21 2018, 08:22 PM


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