89 Cherokee Lerado, long slow start no power dies.

Hello! noob here!.
I have a 89 Cherokee Laredo, 4.0 inline 6 4x4,(owned 11 years).I was driving one day(engine has been running well)for about 17(Highway)miles and stopped at a red light, stepped on the gas and the jeep choked and was sluggish for a few seconds with almost no power(that scared me!), drove for 2 more miles(everything ran OK) pulled in to a resort parking lot went in for awhile (30min) came out, got in jeep turned the key, and noticed that it wasn't turning over smoothly(sluggish)(took longer than normal), put it in reverse and stepped on the gas and the engine had almost no power (lost more than halve the RPMs),jeep barely moved and engine hesitated then died!, got out checked under the hood found the air filter cover had come off!,and the filter was forward from ware it should be , (noticed some debris in the bottom of the canister) removed the debris, and closed it up, turned the key and the engine took about 4 or 5 seconds to start, when it did, it ran rough!. Tried driving it, but every time I stepped on the gas it would lose power, ease up and the power came bake up!. Got out and checked for loose wires or hoses(found a broken wire coming from the Starter Rely box, it comes from the battery post(small red wire, and then goes to more wires, patched it). I really needed to get home so I tried to drive it, but could barely get it to go, limped it about 1 mile, parked it, called for a ride!. Next day checked fuel pump and fuel filter,(fuel filter had dirty fuel come out, fuel from tank was clean), put new fuel filter on, got engine to start "sort of", engine would start, but not stay running for more than 30 seconds or so, and if it stays running it runs very poorly, sluggishly idles very low RPMs to normal back to very low up to higher then to low then after awhile of that, dies very sluggishly!. Managed to get it home! but could not go very fast(20-40 mph) and had to keep pumping the gas peddle to keep engine from dieing!(boy was my foot sore when i got home!). Since then I've tried to get it to stay running, but no luck! it will idle a little better now (and sometimes even worse!) but if you try to drive it dies when you step on the gas while in gear!,not so much in neutral tho! but still has same choking effect in neutral but not as much, not as severe as when in drive.
So any ideas on what could be causing this??.
THANK YOU! FOR ANY HELP!!  

i would check your map sensor it should be at the fire wall and have a vac line from it to the intake if it is borke or fell out of the intake hole where it is soposted to be it will run like *** anyways hope this help  
2000 WJ 4.7, 4" RC lift magana flow and k&N cool air intake 88 Cherokee 4.5 RC lift 33s MT fount assuie locker

Nope! checked, everything looks good!?.
when I try to open up the throttle, the engine sounds like it either needs air or fuel? not sure!?.
looked into the air intake(as far as I could see) didn't see any obstructions!. hand placed over breather hole has strong suction!. Pressing in on the fuel pressure relief valve puts out strong spray!, but only while engine is cranking?, no fuel comes out if you just turn the key on, or just turn the engine over a few times without kicking over!, is that normal?.
Oh! the fuel pump is one and a half years old!.
Thanks for the reply though  

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First off!. please!, take your internet trolling somewhere else.
this site is about people helping other people!. Not someone trying to scam other people out of their hard earned money!. I see "he?" joined and canceled same day.    

Now that I said that!
I tried the test of unplugging the vacuum line on the MAP and the engine idles better, but not stable, plug it back in and engine dies shortly afterward.
I also unplugged the IACV and could get it to start a little easier, but unplugged it causes engine to idle higher.  

well that very odd about the fuel. I would start form the begining and check plugs wires distrubiter and also fuel filter  
2000 WJ 4.7, 4" RC lift magana flow and k&N cool air intake 88 Cherokee 4.5 RC lift 33s MT fount assuie locker

Releasing the pressure in the fuel rail doesn't really indicate much. If you're going to test the fuel pump, you need to test for both volume and pressure.

Long starts and cutting out are both classic symptoms of fuel system problems. If it's the original pump, I'd replace it and don't even bother testing it. If that doesn't fix the problem, I'd pull the injectors.

You can test the injectors using an ohm meter to test the resistance. If they aren't within spec, replace it. But, that only tells you if the injector is capable of pulsing correctly and does not indicate if the tip is clogged or worn causing an inferior spray pattern. That takes an injector flow tester. Again, if the injectors are original, you might just consider replacing them.

Most of the sensors are not used until the operating temperature is reached. The computer just uses a default fuel map when the engine is cold.

As suggested above, you might also want to give it a tune-up, but I don't think that's the problem. Sometimes you can see a bad wire shorting or a cracked plug by running the engine in the garage or on a dark night. You'll see the arcs. If you do it in the garage, make sure you vent the exhaust with a tube if you have to shut the door to make it dark!  

Thanks for all the replies everyone!.

I had noticed that when the IACV was unplugged if I pushed on the gas peddle it was more responsive than when it was plugged in (didn't choke as quickly!,and if I press on the gas peddle slowly it revs up normally, but there is a slight rumbly popping at around 3k > RPMs. and I also tried the jumper test for the fuel pump resister, and there was no change in performance. I also am wondering if it is possibly something down inside the air intake(if you read my 1st post) the filter had come loose!and there was debris (leaves) in the bottom of the housing!. could that cause the lack of power on quick throttle up move's.(I did take a look inside the air intake, but I couldn't see all the way into it).

Time is short so I'll keep-on looking for vacuum leaks or any broken wires.

I'll keep reading the really good suggestions till then, and try and find the problem.

THANKS AGAIN!!



Added  06/21/2009

Well today I found one of (if not "the!")problems , there was A melted and bare wire showing threw the CPS cable, about half way on the cord!. Looks like it got to close to the exhaust heads and melted, ,now I'm going to see if it can be patched up?.  

Well! CPS is not the prob?.
replaced CPS didn't fix the problem, also changed the MAP, still no change!.

If i unplug the MAP vac line and the IAC plug I can get the jeep to start,(after many many cranks), its starts with a slow sluggish chugging, and occasional soft popping every now and then!.

This is starting weary me A little ***

I need to get this thing running!!!!

any other suggestions, anybody?, anybody!  

Fuel pump and/or leaky injectors. It's showing classic symptoms of a fuel related problem.

If the CPS is bad it'll never start. It has to have a signal from the CPS to fire the plugs. I really doubt it's a sensor. Maybe it's the IAC but that can be eliminated as a posibility by holding the throttle down a little. The IAC controls idle. Would not explain the cutting out under load.  

Thanks for the reply!.
But there isn't any leaks on any of the Fuel injectors(that I can see).
but I did a little test today, I disconnected the fuel filter near the pump!
to check and see if there was any fuel coming out when you turn the key "I was curious" (as far as I know it should!) it did the first time, and came out with a good flow, but I noticed that it didn't on the next 3 or 4 key turns then did on the next!, shouldn't it be coming out every time the key is tuned?. And there was fuel coming out of the return tube (good!, right?), but it only had fuel flow on some key turns but not all!. ( I did wait between each turn for a few seconds to a minute or so).

does that deepen the mystery?.

I would like to remind everyone to remember that I did find a broken wire coming out of the positive post on the starter relay box on the day the Jeep started acting up (it's the one that has a bunch of other wires going to it including one that goes to the positive battery post. All the rest just have a single connected wire!). It's a red wire that is connected to three more red wires that go "?".
Any idea what they may go to?. My guess is that this is what's causing this issue, must have damaged something it is linked to?.  

The injectors leak internal. You wouldn't see any fuel. One of the tests to check fuel pump performance is to turn the key on, without starting, and let the fuel pump pressure up the system. You should be able to hear the pump run through the fuel tank filler tube. The pump should only run for about a second at the most

Then turn the key off and let it sit for 15 minutes. Then turn the key back on and the fuel pump should click on and then back off very quickly, again less than a second. If the pump runs for more than a second to pressurize the system on this second attempt, that usually indicates leaky injectors. This is a common cause of long starts.

But you should make sure the pump is working correctly before the "leak" test.

If you think you're having electrical issues to the pump, causing the pump to not run, you need to test for voltage at the connector to the pump. The correct way to test (generally) is to probe the backsides of the connectors, not to unplug them. This may take some test leads with very fine probes. If your test lead probes are too big you can use a paper clip straightened out. But, becareful not to cause a short if you use paper clips. Radio Shack sells adapter pobes.  

Thanks, but would that also cause the power loss when I try and rev the engine quickly?. And the die-outs when I connect the MAP?.  

When doing diagnostics on a car you have to make an educated "guess" based on the symptoms, for a starting point. Then you have to eliminate potential problem areas by "tests". It's very difficult to figure problems out if you just keep guessing. You have to start testing to eliminate a component as a potential problem. Then move on to your next best "guess". This is the fastest and cheapest way to find the problem.

Here is a link that will help you test the sensors on your Renix based injection system. But you should also have a Factory Service Manual (not Chilton or Haynes) that describes how things work, where components are located and true/false charts to guide you in the right direction. They cost about $100 new or you might be able to find one on the internet for less. IT'S WORTH EVERY PENNY if you're going to work on your own car.

Don't just start replacing stuff. That's expensive in terms of time and money.

Click Here for sensor testing info.

Again, I don't think it's a sensor issue. But if you think it is, test the sensor.  

OK, I guess I'm being impatient because I really have to get this thing running before 7/1/09!. I "have to move" and this thing is (or was) my only vehicle!.
I don't have the money to take it to a real mechanic!, or I would happily do so.
I'm rapidly running out of time.

Enough sob story, "SORRY!"

One last thing "I hope!", is that I "can" get it to run barely, when it does run (still has the quick rev-up,and hard slow start issue) now I've noticed that when I put the MAP vac line back on, if I can keep it from getting too low of an RPM (it wants to drop to below 100<, it's not easy to keep it above 100>, it well rev normal "quick/slow". But it wants to drop the RPM so low that the engine dies!.

I do appreciate all the help you and anyone else has tried to give to me.

But! with my back is against the wall and the wolves are snarling at me!,
playing dead doesn't help me!. So I'll keep trying to fix this JEEP!

THANK YOU FOR THE HELP!