Justy with a bunch of issues... opinions?

[zyewdall]

So... the Justy is not happy.  It died on the road the other day, and the local suby shop looked at it.  

 

It's a 1991 Fuel injected 4wd 5 speed btw.

 

Symptoms have been an intermittent CEL for crank angle sensor for a while -- then I replaced the distributor about a year ago, and it has had a constant crank angle sensor code since then.   But it still ran and drove.  A little bit of high rpm hesitation sometimes, and lousy gas mileage though -- like 29mpg, and it usually got more like 33 to 36 before the CEL.  Then, all of a sudden, it wouldn't rev at all -- would idle okay though, and limp along at 5mph at idle.  But the slightest bit of throttle would make it almost die instead of revving up.  I suspected bad fuel filter, as it was acting like fuel starvation, but filter seems to pass fuel.  Oddly, I got it run much better by advancing the distributor quite a bit -- enough to get up to 40mph or so.   The shop looked at it and said it needs a new distributor, engine temperature sensor for the computer, O2 sensor, and they also found a vacuum leak which they did replace.   $800+ to replace all of that, so I just drove it home instead.  I'll get the parts and do it myself... the question is, what parts, and could it still be something else?   Sensors are cheap if I do them myself, so that's a no brainer, but the distributor is the worrisome one.

 

In particular, I'm worried that its the distributor wiring harness, not the distributor itself that is bad, because replacing the distributor once didn't help.  My parts car is a carbureted one, so different disty, so I can't try that.  I guess I could go back to the original disty and see if it goes back to an intermittent CEL.

 

Oh... and one more not so good thing, I think.  After it's all up to temp, the oil pressure light flickers and goes on at idle.  I need to put a real mechanical gauge on there to see what it really is, whether it's really bad oil pressure at idle, or bad sender or light.   Only about 30k on a rebuilt engine.  But, if it really does have bad oil pressure at idle, is it worth fixing the other issues... and why would it be bad after only 30k.

 

What do you think?

 

 

[TallonX]

Sounds pretty close to what a clogged catalytic typically does

[ferox]

Yeah Justy distributor wire insulation is prone to cracking.  As you have surmised, you're going to have to inspect every wire individually.  

 

What is your timing set at?

 

When the engine was rebuilt, was anything done to rehab the crackcase plate?  Were new oil pump internals installed?

 

You should have an o2 sensor on the pre-cat.  I suggest disconnecting the pre-cat from the exhaust manifold to inspect the top of the matrix.  If it doesn't looked clogged, leave it be.  Direct replacement pre-cats are $300+ and the universal ones require modding the stock exhaust to fit.  

 

Do not ream out the pre-cat or the car won't run correctly.  The pre-cat volume is sufficiently large to cause the velocity of the exhaust to slow down a lot right off of the manifold, so it acts like a substantial exhaust leak, which incidentally will make your fuel mileage go down dramatically.  If you pull the pre-cat and the metal matrix is damaged, that might be a large part of your Justy performance problem. 

 

I would also recommend pulling any and all FI sensors and cleaning them, along with the O2 sensor replacement.

 

and replace the fuel filter anyway.

Edited April 18, 2014 by ferox

[idosubaru]

if the symptoms changed when you changed distributor (sounds like it may have definitively went from intermittent to constant), then that probably points to your issue.

 

ferox knows what he's talking about so wiring sounds like a good place to start and could change symptoms with the work you did, needing to be moved, unplugged, etc.

 

another bad distributor?  seems unlikely but if you're at a loss can you install the old one again to test?

 

the justy's are tempermental with oil pumps right?  i'd assume that's a real issue and do something about it right away.  pretty sure you can google that and find out about justy oil pump/pressure/supply.

 

with those existing check engine lights i highly doubt the converter is the issue.

for every 10 times people say "catalytic converter", more than 9 of them it ends up being something else.