View Single Post
  #4  
Old June 21st 07, 12:16 PM posted to rec.autos.tech
AWN
external usenet poster
 
Posts: 41
Default Engine Miss in Blazer S10 4.3 Vortec

You will see a small shraeder valve behind the air plenum to the right of
the distributor (right behind cyl #5 I think). You need a fuel pressure
gauge to do this properly. I'm going to guess that it's either a bad fuel
pump or pulsator OR the dreader fuel spider under the plenum. If you want a
quick check, open the throttle plate and stick in a mini light and mirror -
look for very clean, shiny spots to the left and right side. If you have
gas smell and a clean spot to the left, you may be able to replace a fuel
pressure regulator and be back in business. If the leak is on the right,
you likely need new fuel inlet lines (aka, 'nut kit'). If it seems that
it's leaking all over and you just want to do the job properly, get both the
fuel spider and nut kit from either Linder Tech or an AC Delco dealer. The
first step is to ensure that you're getting 58-62psi consistently with the
key on engine off. It should drop to maybe 52psi when the engine is
running. If that pressure doesn't hold for more than 10min-an hour, you
have a leak in the fuel system that needs to be fixed. Can you smell fuel
when exiting or entering the vehicle?

Thanks and let us know. I just went through this and I'm not in the clear
after replacing the pump, fuel spider and nut kit. I also did the cap,
rotor, wires, cleaned the EGA, IAC, MAP replaced, etc... Don't throw away
money till you check your fuel pressure. Have the codes shown that cyl #1
is missing or is it random? If it's cyl#1, it's likely a leak on the fuel
inlet side because fuel can leak down into the cyl easily on that side (in
my experience).


Andrew.



in article , dahpater at
wrote on 6/20/07 6:02 PM:

> On Jun 20, 5:12 pm, packard > wrote:
>> My 1993 S10 Blazer is running low speed rough idle. I replaced the
>> rotor and cap, spark plugs (wires are 3 years old), cleaned the EGR
>> valve and put a new gasket in the EGR valve.
>>
>> Can anyone give me an idea of what can be causing the problem?

>
> Clean the throttle plate.
> Replace the fuel filter and check the fuel pressure.


Ads