Fuel injection?

 I ask here because you guys know everything.

My 88 Caddy has started to stumble when I stomp on the gas.  It's got
56,000 miles on it (it was my mom's car) and she had it tuned regularly,
except it hasn't been touched except to change the oil and filters for
perhaps 3 years.  I'll probably pay for a tuneup when it needs to get
smogged in May, but I'm wondering if there's anything simple I can do now.

I can run it up to high speeds with no problem, I just have to do it
slowly.  Not that I'm addicted to jackrabbitism, but every once in a
while you DO have to pass somebody.

I've never had anything but carburetors before.  Is this likely to be a
fuel-injector problem?  Is there some magic stuff I can pour into my
gastank that will solve the problem?

--
Cheers,
Bev
++++++++++++++++++++++++++++++++++++++++++++++++++++
               Non illegitimi carborundum.

 
I would try that first, some STP or something. Then look at the plug
wires and check for vacume leaks (read on). If that doesn't work and
you are handy I would suggest a Mitchell Manual and check the Throttle
positition sensor. That is however based on very limited information
you have provided.

If you are going to work on FI you should take some notes about the
runability. This can help you diagnose the problem.

When does it happen? All the way up through the acceleration or only
at certain points in the rpm (throttle positition)?  If it has bad
spots in the accelleration/decel/cruise and not at others. I would
take a real good luck at the Throttle posisition sensor. Those old GM
TPsensors go bad a lot.

Does the outside temperature or humidity make any difference and if so
what? Sensors and chips could be suspect here or pointed to. But if
the skip is all the way up through the RPM range while under load, I
would look at the plug wires. You can hold down the brakes, put it in
drive and "load" up the engine by applying some throttle (the intent
is to not let the car move forward). Please don't do it against your
house, or anywhere where if the brakes let go, any damage could
occur...I am trying to help here;) As you bring up the rpm does it
buck and break up and skip through the rpm range? If so, wires and cap
are looking more suspect. Try spraying the engine with a hose,
specifically the plug wires and such. and "load" it up again. If it
gets worse, think plug wires, distributor cap, sparkplugs, mosty the
wires and cap though.

Does it happen when the engine is cold as well as hot, inbetween? Does
it idle correctly or only when cold, or hot? This could point more to
sensors, or the wiring to them. This could also point to vacume leaks.
Check all the vacume lines for breaks, unexpected open points (find
out what they used to be connected to) and to be sure they are not
clogged. You can also spray hydrocarbon based cleaner such as cyclo
around the engine (avoiding the intake itself) and see if the RPM's
change indicating an air leak into the intake or a vacume line. Note
though, vacume leaks tend to be less noticable as the rpm (normal
intake/restricted leak) go up.

These are only suggestions based on how I would start looking at your
car if I got it cold...

Hope that helps, Good luck, Scotty

 

 snip


It doesn't sound like a clogged fuel filter, but maybe?

Joe

XL600R

 
Go to your favorite auto parts store and buy a can/bottle of injector
cleaner. Fuel injectors have a much higher clearance than the old
fashoned carburators. Gunk buildup happens at a faster rate than in
normal situations. I can't wait till they put fuel injection in
dirtbikes. OF.

 oldfart wrote:


See long response to justwaitafrekinminute.  Water-cooling seems
sufficiently non-motorcyclic, but I suppose FI and automatic
transmissions (yeah, I know, I think KTM had them a long time ago) are
the wave of the future.  Maybe add a couple more wheels for stability...

--
Cheers, Bev
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Some people are like Slinkies... Not really good for
anything, but they still bring a smile to your face
when you push them down a flight of stairs.