anrchy

Ok here we go...

1988 cherokee Pioneer 4.0L

BEFORE
runs OK, dies when you come to a stop unless you are applying slight throttle to keep rpms up.

Had oily air filter problem. Cleaned out inside of valve cover replaced gasket, air filter and CCV hose.

AFTER
Now when you start it up it idles higher then normal and then shortly it will die. If you apply light pressure to throttle it will die instantly. If you apply hard throttle it will hesitate a few times as it revs up but then die after a few seconds of holding the RPMS steady. Pumping the throttle it hesitates (sputters) then will die soon after.

After looking around the engine compartment I see a few things that are not right, See Pictures. Any help would be appreciated, i dont understand why it runs worse after fixing a problem.

The 2 white dots are holes in a rubber boot on the passenger side of the throttle body. Nothing is plugged into these holes and this hose is the only thing that i see that looks like it is suppose to goto it, it looks broken on the end and it comes from the thing circled in white in the next picture.

http://i15.photobucket.com/albums/a3...y/IMG_0227.jpg (Vacuum hose and throttle body)
http://i15.photobucket.com/albums/a3...y/IMG_0229.jpg (Where vacuum hose comes from)

This thing I have no idea what it is but the red wire is cut the black wire goes the the starter and the other wire is missing. Don't ask me why it is upside down, the original isn't and i rotated it in photobucket and it is still like that. on drivers side fender next to airbox.

http://i15.photobucket.com/albums/a3...y/IMG_0236.jpg (3 wire connector)

And This thing has always been unplugged and if we plug it in right now idle speed is lower and more rough and it smokes real bad. I cannot find it anywhere in the chilton. Both wires are orange with black stripe. Drivers side front attached to fender next to airbox.

http://i15.photobucket.com/albums/a3...y/IMG_0235.jpg

alpine.adrenaline

Plug those two holes, they're causing a vacuum leak and they should be connected to vacuum lines. Plug those and the lines just to determine whether your idle will drop. There are plastic elbows or sleeves that connect the lines to little nipples on the sides of the throttle body, you might be able to find them at a junkyard. The thing against your firewall is your MAP sensor, that MUST be connected in order for your engine to even begin to idle well. It should have a vacuum line from the throttle body.

The other thing is your power distribution block (at least that's what it looks like from this side). It doesn't look like its doing anything though, you should have several other wires running to it.

That last white thing is your ballast resistor for your fuel pump, but like your distribution block, doesn't look like it is connected and doing anything.

beavervango

my vacuum line for the first pick goes in the bottom hole. it had a slight crack in it and ran like crap. got some small inside diamater rubber automotive hose and some rtv to fix it. rtv the hard plastic lineabout 1/4 in away from the ends then insert into the hose to prevent shoving rtv into it self . and X2 on the ballist. (white ceramic thingy)
your silver block i couldnt see on mine, but tomorrow when i have daylight i will see if i can find it and take a pic to try and help.

anrchy

Ok so second picture plugs into bottom hole on first picture right? But what plugs into the top hole in picture one? Anything?

Ok and the third picture has only 3 connectors on it the black one runs up along the firewall to the passenger side and goes down to connect to the starter the red wire is cut and the other connector has nothing plugged into it do you know what they are suppose to connect to?

And the fourth picture adrenaline says it's a ballist resistor for the fuel pump. When I plug that one in it runs way worse and smokes. Didn't realize for 4 months it wasn't even plugged in. Jeep ran decent before the ccv fix. Both wire are orange with black stripes one appears to follow inside the wiring harness into the firewall. The other one is unplugged and I followed it inside a wiring harness that goes inside the core support to the passenger side then has a plug on the end where it continues as the same color and into one of the 4 relays that are next to the cec diagnostic plugs.

I'm going to rtv the rubber boot on the throttle body cause it is slightly loose and the rtv the map sensor vacuum line into it but I need to know if anything plugs into the top hole or what. And anything on that 3 way connector would be sweet.

Thanks for the help guys you have no idea how much this will help me out getting this thing running.

CAEMI

Sounds like vacuum...but worn piston rings will cause blow-by which will also cause problems idling and oil in the air filter.

beavervango

My plug to the throttle body was loose as well so i too rtved it. On mine nothing plugs into the top hole. There isnt a hole into the throttle body, just a dimple. sorry about he rest i still need to go take some picks for you.

beavervango

I just went and looked for the silver relay looking thing and mine doesnt have on that i know of. Sorry!

anrchy

When we got the jeep we found out it had oil all over the air filter. It ran pretty good at the time with no idle issues. A quick google search showed me the different possibilities that it could have been. So I checked the CCV hoses and we found that the rear small diameter hard plastic hose was slightly clogged we cleaned it and the front hose that leads to the airbox. I then placed a small K&N filter on the end of the front hose so that any oil leaking out would not ruin the air filter we had just bought. it seemed to work for a little bit but replacing the rear hose was the next best step. We just did this and now it runs like crap and is not driveable. Thats the only thing we did, also cleaned out inside of valve cover. haven't driven the vehicle but it has been started several times and there doesnt seem to be any oil depositing onto the air filter yet.

So I hope the piston rings are fine. I don't want to have to do that kind of engine work.

So i'm trying to figure out why it is running way worse after fixing one of its problems. I wonder if that hose was in the throttle body before we did the fix and maybe it got bumped while removing/replacing the valve cover.

Thanks beavervango, i am going to rtv that hose today and see if anything happens.

I appreciate all the help you guys have given me thanks alot.

anrchy

So this is where I am at... Vacuum hose from map sensor is epoxied (all we had no car to go get some rtv) into lower hole in rubber boot which is epoxied into throttle body. Slight change now, dies very fast and any throttle will kill it.

BUT... check this out. I took a voltmeter to the black and gray wires on the TPS (throttle position sensor) and with key on it reads 4.77V which is good (suppose to be around 5V) but the blue and black wires only read about 0.0V - 0.2V tried adjusting the tps and can only get it up to .3v but then i opened the throttle all the way and it reads .7V which is suppose to be 0.8V with the throttle plate closed. So my TPS is bad, its around $50 but I have a hookup at autozone so its only $35. gonna pick it up tomorrow and put it on I will tell if it works.

I also took the 02 sensor off and cleaned it up real good with cleaner. So I am crossing my fingers!

Again I appreciate all the help you guys have given me.

-anrchy

BillyBoy

Yall are a bit beyond my realm with measuring volts and so on, but i will say, make sure to unhook your battery for about 5 mins between all these changes. It resets you computer to allow it to account for the new changes and lets it try to make sense of its fuel/air mix.

Small thing, but it's helped in the past.

Good luck-

4jeepers

The top hole is plugged, It does nothing. The bottom hole must supply vacuum to the MAP sensor or your Jeep is not going to run very well if at all!

anrchy

Ok so all is well replaced the TPS and set it at the correct position to achieve .8 volts and then the orange wire that had to be unplugged in the past for it to run right HAD to be plugged IN now to run right so everything is running way better than it ever has.

But it didnt pass DEQ, hydrocarbons passed but it failed the carbon monoxide test, has to get a 1 and it got a 2 on both the 1st idle and the 2500rpm tests. So now i have to figure out how to get it to pass DEQ. this sucks.

But I wanted to thank everyone for all there help it would have taken me longer to figure out if you guys hadnt lended me some of your knowledge.

-anrchy

beavervango

Glad to hear you are making some good progress. Bummer about the emmisions crap, thats another reason i like living out here in the middle of nowhere, no emissions, just safety. Pretty sure mine would pass just don 't want the headache.