Expert: Roland Finston - 10/13/2011

Question
QUESTION: Dear Roland I have read through most of the items and hope you can advise me... I have a 1988 crysler labaron TURBO model that keeps getting super rich feeds for emmisions despite how well it runs and the mileage it gets (24 - 30 mpg). This model does not have or need and EGR system so I am at my wits end and wonder if I should just give up and scrap it out.

I have changed all the filters, plugs and wires, oil,  oxygen sensor and coolant /air temp sensors and had a new catalytic converter instaled  and still am getting the following reads:

high speed: HC 213/220 PASSED  CO 2.74/1.20 FAILED
idle test: HC 838/220 FAILED CO 7.80/1.20 FAILED

ANSWER: Hi Sabrina,
I assume this if the 2.2L Turbo II engine. I would consider a couple of possililities:
How about the spark timimg: did you check that by removing the plug on the coolant temp sensor (the fan will come on, which is normal) and then check whether the timing mark at idle speed (850 rpm) is showing 12 BTDC? Lossen the bolt on the distributor and rotate it slightly to meet that spec.
Have you tried for fault code readout using the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapses time? Then watch the 'power loss' light, which remains 'on' to see it flash, pause flash, etc. Count the number of flashes before each pause. Then repeat the process to be sure or an accurate count set. Let me know what you get and we'll go from there.
It is also possible too that one of the injectors is leaking which will cause a too rich mixture. You might do well to remove the spark plugs and inspect to see whether any one of them looks to be wet with fuel or showing a heavy deposit of carbon. That would be a candidate for replacement.
Finally, a readout of the voltages on all the sensors might show one that is inaccurate but not so badly as to set a fault code. But lets try the above first.
Roland






---------- FOLLOW-UP ----------

QUESTION: thank a bunch... I will definately recheck the timing. Have done a fault code check but only came up with what the emmision test told me that the fuel was to rich which lead me to changing the sensors as shown above ... the plugs were changed recently and at the time they did not show any sign of serious carbon fouling or oil saturation , just basic use ... will pull pull them again and check to see if there is any signs on new plugs.... also rechecked for codes after doing the full tuneup and clear for new codes and now do not get any exceot the cide that tells that the codes have been cleared during last 50 key starts... not sure about the efi fuel rail injection may have to have a shop check it since I am not experienced enough to dismantle and reassmble the system... you are great to offer your help to all of us crysler loving people.. I have owned several over the years this just seems to be an inigma to me... even the emmision station felt sure it would fly through emmisions because it seemed to be running so well

Answer
You are welcome. If you find that an injector is leaking then I can xerox and postal mail you some pages that show how to remove the fuel rail and change out an injector. When you check the plugs for wetness, I would start with a cold engine, start and run it just long enough to get a smooth idle, then turn it off, pull the plugs and compare/examine. When the engine is cold you might have a better chance at detecting excess fuel on a plug before it evaporates.
High HC could also be caused by a small vacuum leak so check over all the vacuum hoses for any cracks or leaky connection points. You can have high HC either from too rich or too lean, thus the possibility of a vacuum leak that leans the mixture should be considered as well. Also  to reduce hydrocarbons you could try cleaning the combustion chambers as follows;
Find one of the vacuum lines that is sucking at idle, add a 2' length of hose to it and reattach, start the engine and warm it up, and then with a helper to keep the idle at 1500-2000 rpm, disconnect the extended vacuum line and allow the engine to SLOWLY suck in through the extended vacuum hose about 8 oz of water from a glass of water. By slowly, I mean it should take 30 seconds or more to suck that amount of water so as to not damage the engine.
When you check the timing be sure to disconnect the plug from the coolant temp sensor first.
Finally, be sure the engine is fully warmed up when you go for the next test.
Roland