gv@mtuxo.UUCP (g.valentini) (08/21/85)
I have a Mercury Capri with a carburated 2.3 liter engine.
I am experiencing backfiring when ever I let off the gas.
Would anyone out there know what causes this and how I can fix
this? Thanks.
George Valentini
mtuxo!gv
(201) 576-6198rls@ihu1g.UUCP (r.l. schieve) (08/22/85)
> I have a Mercury Capri with a carburated 2.3 liter engine. > I am experiencing backfiring when ever I let off the gas. > Would anyone out there know what causes this and how I can fix > this? Thanks. > > George Valentini > mtuxo!gv > (201) 576-6198 I unfortunately have had a lot of experience with the 2.3 liter engine as I had one in the Mustang I sold this year. There are other causes for backfiring but the one that I would suspect most from the 2.3 liter 4 banger is timimg problems and you may have to go further than just checking the timing with a timing light to be sure. Your engine has a timing belt under a cover in the front that connects 3 points. The driving point is the crankshaft at the bottom. The things that it drives make this engine somewhat different. As with most engines the crankshaft drives the camshaft (overhead cam in this case). But on most engines the camshaft drives the distributor and oil pump. On the 2.3 liter engine the distributor and oil pump are driven by an auxiliary shaft which is the third point the timing belt contacts. (gosh my big chance to draw a picture!!!!) _ /O\ < Cam | \ | \ Crank > \O__O| < Auxiliary Front View There is also a tensioner under the belt by the camshaft to help hold the belt tight only during initial installation. It is held in place by a locking bolt so it cannot take out the slack that eventually developes. A timing light will tell you if the crank and auxiliary shafts are in sync but will tell you nothing about the cam shaft. The timing belt is notched on the inside but as it wears and gets loose it can easily slip a notch. The only way to be sure every- thing is in sync is to go through the alignment procedure. There are marks on the crank and cam visable from the front with the timing belt cover off and the auxilary shaft id positioned so the distributor is pointing at cylinder one when the crank and cam are lined up. The problem is probably due to an old timing belt that has slipped and needs to be replaced. My engine had a turbo which incorporated a high volume oil pump. The auxiliary shaft drives the distributor and oil pump by the gear at the back of the auxiliary shaft driving a ring gear held in place on the distributor shaft by a roll pin. The added drive needed by the oil pump at high RPMs sheared the roll pin. The ring gear would slip a little and the car would die. I would readjust the timing and the gear would hold in place until the next time I really pushed it. I played around with the timing belt 3 times before I thought to check the roll pin *&%$#@@!! Good Luck Rick Schieve ....ihnp4!ihu1g!rls
wjh@bonnie.UUCP (Bill Hery) (08/22/85)
> I have a Mercury Capri with a carburated 2.3 liter engine. > I am experiencing backfiring when ever I let off the gas. > Would anyone out there know what causes this and how I can fix > this? Thanks. > I'm not sure what's causing the problem, but I'd suggest looking into it quickly. Depending on when the 'bckfiring' occurs in the cycle, the backfire will either go through the exhaust system or the carb. If it is going through the carb (and you should be able to hear the difference), it can be dangerous (gas in the carb might ignite), and it can severely damage the carb pretty quickly.
saltiel@cdstar.UUCP (Jack Saltiel) (08/23/85)
In article <908@mtuxo.UUCP>, gv@mtuxo.UUCP (g.valentini) writes: > I have a Mercury Capri with a carburated 2.3 liter engine. > I am experiencing backfiring when ever I let off the gas. > Would anyone out there know what causes this and how I can fix > this? Thanks. The most likely cause of this is simply that your mixture is adjusted to be too rich. In english, this means that the gas/air ratio is too high. If your exhaust pipe is black this will confirm this problem. When you back off, uncombusted gasoline finds its way into the exhaust and the heat there causes the unwanted flatulence. This will require a carburator adjustment. Since I am a fuel injected hacker, I have no carb experience, but it should be easy to find. -- Jack Saltiel Cambridge Digital Systems {wjh12,talcott}!cdstar!saltiel "Nailed retreads to my feet and prayed for better weather."
ccs009@ucdavis.UUCP (Dennis Michaels) (08/27/85)
> I have a Mercury Capri with a carburated 2.3 liter engine. > I am experiencing backfiring when ever I let off the gas. > Would anyone out there know what causes this and how I can fix > this? Thanks. > > George Valentini > mtuxo!gv > (201) 576-6198 Sounds like your gulp valve, that is , the one-way vacuum valve that closes the minute you take your foot off the gas, or is supposed to ... not expensive, relative to the national debt, and does a world of wonder for those backfires too....... D.M.