[V8] Rough idle on start up issue

[Ed Kellock]

My car exhibited exactly this behavior last winter. Mine was caused by a 
vacuum leak.
 Since you just acquired the car, one of the things that you should most 
definitely do is vacuum leak patrol. There are a couple of breather hoses 
that get soft and deteriorate out of sight and by themselves.
 Back of driver's side head there's one that goes down in inboard to just 
near the intake manifild intake under the filter.
 Across the top of the engine (under the cover) there's one that goes from 
valve cover to valve cover.
 There's another short one that is in the front driver's side of the engine. 
Not as common to have a problem with this one which is good because it's a 
bit harder to replace.
 On the rear of the intake manifold/top of the engine there are a couple of 
small vacuum hoses. There's one that goes from side to side, inboard of the 
valve covers, up over the intake manifold intake. There's another that 
attaches right next to it on the passenger side that goes to a small check 
valve and then to the firewall to provide vacuum for the climate control 
system (this is the one that I fixed in the scenario mentioned above). 
 There may be a couple of hoses that run from the front of the engine on the 
driver's side back to the carbon canister in the passenger fender well. Not 
sure if those exist on the 4.2 engine.
 To get to most all the hoses mentioned so far you have to remove the engine 
cover. It is also the top half of the air filter housing. There are 4 screws 
visible on top and then 3 phillips screws across the back edge down out of 
view by the firewall. Some people remove the strut tower brace, some don't. 
To lift the cover off without removing the brace, you have to catch the 
filter with your fingers and remove it along with the cover. The lower 
plenum of the air filter housing removes easily... two 10mm bolts. It is a 
snug fit on the intake manifold intake. Once loose from that, roll it over 
bringing the back of it up and forward and you should be able to lift it out 
easily. (From point of reference standing on the passenger side, you'd be 
rolling it clockwise, a bit more than a quarter of a turn before you can 
lift it out.

All this is for the 3.6 engine so do not be overly concerned it you find 
some deviation, but do ask/post about it.
  Poor ignition could cause this too potentially. You could pull the 
distributor caps and check the contacts there. The dist caps are attached 
with 2 small 8mm bolts each. The dist rotors might still be the glue on type 
so don't be too intent upon removing them unless you have replacements in 
hand. Then you can pull the plugs and give them a look. If you find any that 
are too loose, you may want to do some delicate cleaning before 
reinstalling. Buy a set of new Autolite 103's and put them back in. Don't 
bother resuing whatever came out of it unless they're brandy new and the 
correct plug spec'd in the manual (or the Autolites). Anything just isn't 
worth the trouble. The Autolites shouldn't be much more than 10 bux for 8. 
New dist caps and rotors will set you back at least 100 bux.
 All in all, my 2 V8's have given me less grief than just one of my turbo 
5's.
 Ed
 On 9/6/05, Yves Bouchard <YvesB at chromspec.com> wrote: 
> 
> I just got a 92 V8 for my wife,, it run good once hot, the problem is
> upon starting up cold ( 25C) it will not start the first time or it will
> start but the it alsmost stall and then goes back to normal and does
> that 4-5 time then stabilize, after that when in gear it will hesitate
> for an other 1-2 minute and then it run ok,, I have changed the spark
> plug , and cleaned the distributor ( freakenly expensive to change),
> any idea what to look for next , I have pour some fuel injector cleaner
> I it but I have not seen the result yet
> 
> Thank
> 
> Freezing 4 and 8
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