Topic: Gas in the intake manifold

[Jeffy]

I just replaced the thermostat with a 195 Stant thinking my old one was stuck open.

So the coolant temp sensor in the thermostat housing simply sends the reading to the gauge?

Doesn't it also tell the ecu what the temps are so that it can act accordingly?  (i may very well be wrong, i am just asking)

No, the PCM gets it's temperature reading from the rear of the head. near #4 cylinder on the intake side.

[MYSTANGT]

I was just told the following and I quote:

"Its probably from a leaky injector pintle. Its not the O ring. If it was, gas would spray out of the outside of the injector when there is pressure in the system."

Would that explain my poor idle, the gas in the intake and long cranks?  (im just trying to get everyone's opinions before I purchase new injectors, especially knowing 4bangerjp has a few REALLY knowledgeable folks on here)

 

[sharpxmen]

although it can be the injectors it's impossible to pinpoint remotely with 100% accuracy - i still think you need to determine the cause before ditching cash for new injectors. There were a few suggestions made to start troubleshooting, imo you should do that first before you make a purchase

[aw12345]

Normallt speaking the ecm has its own engine temp sensor, Some chrysler stuff is funny
When they use a instrument cluster that gets it's info from the ECM nus it could very well get it's data straight from the ecm. About the only way to make sure is use a scanner and see what the ecm data for engine temp is. When you do look at fuel trim also as well as the map sensor reading should give you a pretty good idea about what the fuel is doing and what is going on with engine vacuum

[dwtaylorpdx]

Long cranking can be a bad check valve on the fuel pump,
Weak Crank Position Sensor,


Dave

[MYSTANGT]

I just replaced the Crank Position Sensor but not much changed.

Whats weird is that it does turn over better than before I swapped the CPS but still not 100%.
***Its not the placebo effect and just me thinking that it does. I didnt tell my buddy that I swapped the CPS and the day after he actually commented that the long cranks issue seemed to have gotten a bit better.

And the fuel pump and regulator are really the same unit on our cars, correct?

So one would purchase a pump and filter and that would basically replace the regulator as well...am i thinking right?

[dwtaylorpdx]

I'd get a fuell pressure gage and hook it up and drive around.
Make sure the pressure does not drop below about 35 lbs as I recall.

Dave

[MYSTANGT]

Where can i get one? And for how much?

By the way...i dont have a shredder valve on my rail. I saw some pics of a YJ and theirs is smack in the middle of the rail, i didnt see one on my TJ

   ??

[sharpxmen]

I'd get a fuell pressure gage and hook it up and drive around.
Make sure the pressure does not drop below about 35 lbs as I recall.

Dave

it's 49psi for TJ, but the issue is that he's got too much fuel by what he describes. but yeah, a fuel press gauge would be one of the things to do

Where can i get one? And for how much?

By the way...i dont have a shredder valve on my rail. I saw some pics of a YJ and theirs is smack in the middle of the rail, i didnt see one on my TJ

   ??

some TJs  came with a schraeder valve on the rail, you might want to look for one of those as a replacement. in the meantime you will need a hookup T to put between the fuel pipe and the rail, they are specialized so you'll need to either get the proper tool or make one yourself (not easy though). you can also weld a 1/4'' NPT metal fitting to your rail (or 1/8'' NPT depending of the gauge you are getting) and put the press gauge straight in there - once you're done with it you can put a plug on. If you want to be politically correct you'll need an AN-4 fitting and a plug, that way you can use teflon stainless steel braided hose to have the gauge in the cab so you can monitor it while driving. Gauges can be found at any auto parts stores, you'll need some adapters if you go with the AN-4 hose.

[dwtaylorpdx]

Arrg I forgot to finish the sentence....

With the gauge connected, it  should jump up nicely to the TJ pressure,
when you turn it off the pressure should stay up some as the check valve
should close and prevent the fuel from running back to the tank.

Mine has had a slow leak for a while, If I have not driven it for a
couple days it takes about 15 cranks to get going.

Dave

[sharpxmen]

Arrg I forgot to finish the sentence....

With the gauge connected, it  should jump up nicely to the TJ pressure,
when you turn it off the pressure should stay up some as the check valve
should close and prevent the fuel from running back to the tank.

Mine has had a slow leak for a while, If I have not driven it for a
couple days it takes about 15 cranks to get going.

Dave

had that too with a bad fpr