jeep stalled now will only idle.....

[jcnoble]

Was running fine then stalled, i can get it to idle with the MAP sensor vacuum unplugged otherwise it will not start. Changed MAP ,plugs, wires, dist. cap , is getting gas to rail, changed fuel filter. Cleaned idle adjustment motor on the throttle body and also throttle body was very dirty. Ideas???? thanks! Im gonna go clean my gun next, haha.

[old_man]

This condition can be caused by the throttle position sensor. Get it to idle then reach down and actuate the sensor without the throttle. You should see the rpms vary radically and most likely die. Have you washed the engine lately. That is what normally kills the TPS. Carb cleaner is even worse than water.

[jcnoble]

I cleaned the throttle bottle with some spray stuff and also used engine degreaser. Hmmm......

[jcnoble]

Nope, new TPS same thing, hard to start and will only idle till warm. And Thats with the new MAP sensor vacuum unplugged. Heres what i changed (I had overheating problem too):
1, o2 sensor
2. Coil
3.Wires
4. Plugs
5. MAP sensor
6. Battery
7. Thermostat
8. Water Pump
9. Radiator
10. TPS sensor
I cleaned all the connectors with contact cleaner also. I looked at the gas, looks clear. The only thing left is the fuel pump, injectors, and the Electronics Contol Unit. Holy Cow !!.. and I still need to pass smog!!!! failed hydrocarbons and carbon monoxide.

oops and fuel filter and dist. cap and rotor...

[skierbri10]

Nope, new TPS same thing, hard to start and will only idle till warm. And Thats with the new MAP sensor vacuum unplugged. Heres what i changed (I had overheating problem too):
1, o2 sensor
2. Coil
3.Wires
4. Plugs
5. MAP sensor
6. Battery
7. Thermostat
8. Water Pump
9. Radiator
10. TPS sensor
I cleaned all the connectors with contact cleaner also. I looked at the gas, looks clear. The only thing left is the fuel pump, injectors, and the Electronics Contol Unit. Holy Cow !!.. and I still need to pass smog!!!! failed hydrocarbons and carbon monoxide.

oops and fuel filter and dist. cap and rotor...

Silly question, from me. Did your throttle cable break? Have you tried reving directly at the TB?

[jcnoble]

Yeah, i can rev it up very slowly sometimes but it mostly will sputter and stall. Good one though, I always ask "Is it plugged in?"

[jcnoble]

The plugs look sooty too.

[jcnoble]

Took off the cat just for the heck of it. Same symptoms but it will start for 5 - 10 seconds with the MAP vacuum attached then die. Still runs for a few minutes with the MAP vacuum unplugged. I think i will test the fuel rail pressure tonight just to get a number. Found the CPS sensor finally, how the heck do you replace that???? Looks like you have to pull the engine.

[Gerr]

for the cps you dont need to pull the engine but it is tight. wasnt hard though to change with a few swivel sockets and long extension

[skierbri10]

The plugs look sooty too.

Running rich, sounds like. Check the voltage on the o2 sensor.

[jcnoble]

New o2 sensor. The output is the typical square wave though.

[skierbri10]

New o2 sensor. The output is the typical square wave though.

I know it's new, but I have had new dead parts before. It is easy to check, and free. You could probably take it to a parts shop and they could check it for you there too for free.

[jcnoble]

It certainly can't hurt. I will ask them about it when i pickup a fuel pressure guage to measure the rail pressure. I did cut into the old 02 and it was cycling once per sec. 1 to 4.5 volts. I think it says in the factory manual the Renix "88" system runs open loop until it warms up then goes into closed loop.

[skierbri10]

It certainly can't hurt. I will ask them about it when i pickup a fuel pressure guage to measure the rail pressure. I did cut into the old 02 and it was cycling once per sec. 1 to 4.5 volts. I think it says in the factory manual the Renix "88" system runs open loop until it warms up then goes into closed loop.

I am not sure what the specs are on the o2 sensor. I have read them on this forum somewhere though. Is your air filter clogged?

[jcnoble]

Freshly cleaned k&n in a slightly drilled out stock air box for better flow.

[jcnoble]

WOW, i got a fuel pressure guage...ive got fuel flow but no pressure. I think the fuel pump must be bad. Either that or the regulator huh? I guess ill go pick up both and install the regulator first then I can return the pump if its the regulator. I hope this does it then I can get gack to my original problem of not passing smog ..

[jcnoble]

Still wrestling with fuel pump, is it easier to drop the tank?? I will let you all know if this fixes the problem as soon as i can get it in.

[Gerr]

make sure you check the relay, its often over looked and is such a simple fix

[jcnoble]

Yes I did that, hey do you know if the electrical connections to the pump are brass?? One broke so I crimped on a steel one.

[Gerr]

i honestly cant remember but its a good possibility since its more resistant to chemicals

[jcnoble]

Im mostly worried about a spark. That could ruin my whole day.

[jcnoble]

I called Canoga Jeep Parts, they said I could use a standard connector on it. I will drop the tank and try to get the sucker installed ... I wonder if smog will pass now that I have replaced just about everything. I hope so , I need to get to the fun stuff. I plan on upgrading from 4.5" to 6" lift , rebuilding front end , new 33" tires etc.etc. and probably creating new problems as I go. But thats the fun of owning an XJ right?

[jcnoble]

Well, i put the new fuel pump in and nothing?? Jumpered the relay and its definately on but no fuel. I pulled it and guess what, the polarity is opposite on the new pump but not marked cause I swappped the leads and it gets great pressure now. Now I can finally get back to getting it smogged. Lets see, the only thing I have not replaced is the cat. Is there a way to clean that up???

[xj4x]

Dont try to clean or gut the cat spend the money on a good strait flow cat that will help give you back some hp your clogged one stole. They are fairly cheap and do yourself a favor have a muffler shop weld it all in place those clamps are only good for placement not for runnin.

[jcnoble]

Can you recommend a brand of cat? The last one I got was whatever they had at autozone. Also my thermostat is reading 210 and water is coming out my cap, this is the second cap, i thought I had burped the system correctly. This is the hottest my rig gets. The Jeep parts guy said they do not warranty the cap unless you buy it with the bottle. Whats up with that?

[goodburbon]

I had constant overheating problems and have heard loads of remedies ranging from "the latest new super cool radiator" to "that stuff that supposedly runs 20 degrees cooler".

I bought 2 electric fans (one larger one smaller), a double pole 10 amp 12 volt relay, and an adjustable thermal switch. Remove the mech fan and shroud (gained the most horsepower of any mod I have done), and mounted the fans to the rad. Next I wired the output from the thermal switch ( which is supplied by a key operated source, in my case the cigarette lighter) to the coil voltage on the relay. tie the air conditioner fan power lead to the coil voltage too. run the fan positives straight from the battery individually on their own relay contacts, and poof, no more overheat, plus the ac kicks at idle! (make sure you get the polarity correct on those aftermarket fans so they are pulling)

do not use a ford starter relay, though they can handle the draw of both fans on one contact they are not made for continuous use and will promptly burn up!

[jcnoble]

I am using one aftermarket fan fron PAW, works good. Its a 12 inch replacement for the aux.

[goodburbon]

you are still using the stock overflow bottle and the hose is good to it and the hose is sealed.....right? if not you'll have overflow and push a little fluid out every time it gets hot, and not take it back in when the engine finally cools.

[jcnoble]

My idle was a little low, like 300 or so RPM, I set it to 750 and now no more overheating. I was only having overheating problems at idle.