Ok

As most of you know i have an 89 YJ with the 2.5L that has been running rich. I have had no luck diagnosing it so i broke down and brought it to the dealer and the told me it was the ISA (Idle Speed Acuator) per there computer codes, etc...

Well, i replace that $130 part (after i pay their $70 diagnosis fee) and it does idle and run much better but it is still blowing smoke. Throttle seems much more repsonsive now.

I went through and checked all vacuum lines and found 2 cracked so i replaced them and 2 others that had some wear. Still blowing black smoke and stinks!

I have a spare engine so i started swapping over sensors and when i replaced the MAP sensor it ran MUCH better but then after 30 mins of driving it started doing the same thing!! Argg. I replaced a few more sensors with no luck.

It runs Awesome when its cool but after about 15 mins of driving and when it finally warms up it seems to be getting too much fuel and starts to bog and blow black smoke.

I replaced the plugs with new ones (old ones were BLACK) and that didnt help much. Air filter is new. The timing is NOT adjustable on this and i am pretty much out of ideas!

Anyone know of anything i might have missed or any ideas??? I cant afford to spend another $70 at the dealer for them to tell me what MIGHT be wrong!

Thanks

If it's blowing black smoke, my first thought would be rings or valve stem oil seals... Check the compression and see if you have a cylinder or two that's low... HTH

you may have a loose or broken wire in the wireing harness to the map sensor. I would start with the plug and be sure the wires are securely attached to the pins.

Originally posted by Newfie:
<STRONG>If it's blowing black smoke, my first thought would be rings or valve stem oil seals... Check the compression and see if you have a cylinder or two that's low... HTH</STRONG>


Not burning oil though and the exhaust smells like GAS big time!

first thing you gotta do is make a friend at a jeep dealer, i never pay for diagnostics.... <IMG SRC="smilies/biggrin.gif" border="0">


there are tons of reasons, i would check wiring, if you get it checked again and it says the same thing, then its definately in the wireing

Originally posted by Newfie:
<STRONG>If it's blowing black smoke, my first thought would be rings or valve stem oil seals... </STRONG>

Oil burning will cause blue smoke. Water white'ish or steam and black is fuel.

I second the wiring thing. Either that or there is an issue with the temp sensors for the puter. If it "ALWAYS" runs good when cold and "ALWAYS" runs bad and smokes when warmed up, I say the puter is getting bad info from somewhere.

Maybe the o2 sensor is bad. <IMG SRC="smilies/biggrin.gif" border="0">

Damn BM,
I bought an 89 Daytona ES 2.5 off of my bro that's doing the exact same thing <IMG SRC="smilies/eek.gif" border="0"> . I've been trying to sort it out.

I was told to replace the oxygen sensor, which I did, and it still does it. Replaced the Cat convertor, the plugs, and the wires. My plugs were black too. I haven't checked to see if the injector was bad yet.. I'm just as lost as you are <IMG SRC="smilies/frown.gif" border="0">

It's probably something completely stupid <IMG SRC="smilies/rolleyes.gif" border="0">

[ 09-21-2001: Message edited by: Jeepster1220 ]

Have you tried the temp sesor for the computer yet? It sounds like it is never coming off of the cold enrichment circut. This couls also be a wireing thing with the temp sensor.

Does the 2.5 have a cold start injector? If it does pull it out and see what it is doing.

HTH

it runs good until it gets hot?

most EFI systems run closed loop until they reach operating temp and then they goto open loop.

figure out which sensors ( prob O2,temp,MAP,MAF) are used in closed loop, and which are used in open loop mode,

good luck!

Originally posted by Boston Mangler:
<STRONG>Ok

Thanks</STRONG>
Hey Boston...
What's up with the finger?.......It was funny for a while but it's getting to be annoying.... Especially when you always have a Question.....I would like to help but I find myself discouraged by the finger...it seems though you are trying to provoke us and it brings unsettling feelings I find myself getting angry at shit like that.....It would seem with all that is going on in the world you would like to unite with others that are like you rather than divide......do you really think the finger is appropriate?........Just my two cents on your PIC. ....it's time for a change...it's up two you........

Originally posted by ozarkjeep:
[QB]it runs good until it gets hot?

most EFI systems run closed loop until they reach operating temp and then they goto open loop.QB]

Actually the opposite is true, open until warm or certain rpm then closed. But start with a temp sensor. <IMG SRC="smilies/usa.gif" border="0">

BTW lose the finger pic <IMG SRC="smilies/glasses.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0">

Originally posted by BossGrip:
[/qb]
Hey Boston...
What's up with the finger?.......It was funny for a while but it's getting to be annoying.... Especially when you always have a Question.....I would like to help but I find myself discouraged by the finger...it seems though you are trying to provoke us and it brings unsettling feelings I find myself getting angry at shit like that.....It would seem with all that is going on in the world you would like to unite with others that are like you rather than divide......do you really think the finger is appropriate?........Just my two cents on your PIC. ....it's time for a change...it's up two you........[/QB][/QUOTE]

since when is POR politically correct? let the man flip everyone off, for chrissakes!

<IMG SRC="smilies/thefinger.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0">

Originally posted by WillyPete:
<STRONG>since when is POR politically correct? let the man flip everyone off, for chrissakes!

<IMG SRC="smilies/thefinger.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0"></STRONG>

Yeah yeah yeah....I was drunk when I did that Quote.....But it's still annoying <IMG SRC="smilies/biggrin.gif" border="0">
Oh and <IMG SRC="smilies/thefinger.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0">

Case in point. The exact reason why I believe DC dont know sheeeite about EFI and plopped a TBI Chebby in.

Jeep wireing is a joke. I agree with the folks above. But unless you're an auto wireing guru (which I'm SAF not) it will most likely be very painful. Via Con Dios amigo.

Oxygen sensor......

try it.

BM,
I finally got a plate for the Daytona, and now that I can drive it, it seems to have cleared up as far as blowing the black smoke. Possibly the computer needed to "catch up" to having a new oxygen sensor in it, and actually putting a few miles on it have allowed it to adjust. Definitely check into it. They're only around $30. At least the Daytona's was...

It shouldn't take that long for the computer to relearn itself!!
Make sure you use a good quality oxygen sensor,cause some brands are shi#!!
Sure sounds like oxygen sensor to me <IMG SRC="smilies/confused.gif" border="0">

Ahhh the joys of efi <IMG SRC="smilies/biggrin.gif" border="0"> Good luck <IMG SRC="smilies/smile.gif" border="0">


GOT PAD? <IMG SRC="smilies/laughing.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0">

i am guessing now since it smells horrible (like rotten eggs) that the new cat i installed is now clogged (from running rich). I am going to pull it out and smash it through until i get this problem fixed (then i will buy a new cat IF i ever fix it)

(I Love Parenthesis)

Thanks

Check your fuel pressure. A bad fuel pressure regulator can cause them to run rich and the ECU can't adjust it.

Well, i hollowed out my cat last night and now it runs MUCH better. Idles smooth, no stink, much more responsive.

That was 1/2 of the problem. The cat was brand new and got clogged cause the truck was running rich. I still havent figured out why (going to test extensively this weekend) but at least now it is driveable without the damn stink.

thanks for all the advice!