Re: ‘91 CQ poor gas mileage/hard cold starts

[DeWitt Harrison]

 On Dec 21, 2018, with respect to a post about poor fuel economy and poor
starting in a '91 20V Coupe, Eric Huppert ehuppert at hvc.rr.com wrote:

"Had a problem with my 200 20v which turned out to be the fuel pressure
regulator. Not familiar with CQ, but would check the regulator. Leaking fuel
injector could also cause leakdown. When my regulator went it actually
caused a hydrostatic lock which busted the starter and ring gear tooth! Car
ran fine but would take a bit of cranking to get fuel pressure up."

I would add the following. I don't know how useful the ecu codes might be
for the 20V Coupe but they might be worth a look. Is the check engine light
on ever? Poor fuel economy sounds like rich fuel mixture assuming the
engine runs fairly well once started and warm. Any bucking/sputtering?

Look at plugs to see if they are wet, black or getting carboned up. Measure
the fuel pressure to establish good fuel pressure regulator. Wiser heads
than mine might know to what degree the O2 sensor mixture feedback system
can overcome incorrect fuel pressure. If fuel pressure is in spec, then
maybe question the O2 sensor itself. Need more data.

DeWitt