I have a 90 xj I have had it about 8 months and now I have to feather the gas to start or keep running. If I give constant gas it just dies. I have replace fuel filter air filter, tps, map sensor, and now am just kinda out of ideas. Any advice would help thanks

 

I'm sure the big guns will chime in soon, but have you shot the TPS?

 

Yeh changed that the map and the fuel pressure regulator

 

Clean the IAC or at least check it? I assume you also checked fuel pressure as well?

Also, may not sound related - but have you refreshed grounds yet? Getting the rpm's up will "cover up" grounding faults, I know because I just had to fix mine again.

Also, what year?

 

I have not cleaned the iac and it is a 90

 

Well hello Hell. Right on-top in the link in my sig. is a link to Cruisers tips. That TPS needs to be adjusted. Check the stuff on grounds, 1,3,4,5 are always good for your Renix Jeep. (TPS adjusting is there too). Be sure that tube to the MAP is perfect . Any blockage or crack will mess things up.


I'm a big "Fan" of taking 3 minutes to check the CPS, no matter what it's doing;

Anyone with an 87 to 90 Renix Jeep has two or three minutes to see that their
CPS is putting out at least .35 AC volts. I don't mean to come off rude, but if you can't connect a meter and turn the key, we may not be much help.
AC voltage CPS test; Small clips on the meter leads really helps. (you need contact with those little pins while it cranks)

Unplug the connector at the back of the manifold with wires going down to the bell-housing/cps. (it's a three wire plug, with only two wires)
Probe the two wires to the cps with the digital meter set on AC volts, a 200 scale on mine. Yours meter may have a lower 2 Volt, or “auto range”.
Crank the engine and note the voltage. (jump it if your battery is low). .35 ( is minimum. .4 to .8 is more like it.



Vacuum leaks can wreak havoc on the idle;

Vacuum leaks suck. I go around with short little shots of starting fluid, if you hit one the sound of the engine will change. Small little shots! You don't want that stuff to accumulate. It's a fire hazard, but It evaporates right away. Also with a tube, or a section of hose you can listen for it. Don't forget the lower O rings on the injectors need to seal as well. (uppers would leak fuel).
The manifold bolts have a habit of loosening, especially that rear one. On anything like that you never want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. I go over about three times. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension. For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep. ALSO, there is a large line coming off the intake, rear of the TB that goes back to the firewall, across, then forward down to the vacuum ball behind your right front bumper. You can pinch that off or unplug it and cap the nipple to test if you have a leak there. The line to the break Booster can also leak vacuum.

 

OH! Yes! the IAC....since it's recommended to clean the TB before adjusting that TPS you should clean the IAT while you are there.

 

Going down the Cruiser Renix Tips list will usually do good.
Taking a fuel pressure would be nice too.

Forgot what year it was, that the TPS was changed to not 'adjustable'..

 

As stated by Flintstone, click on the link to my Tips below. Do 1,3,4, and 5 before proceeding on any wild goose chases or "this fixed mine" rabbit trails.

 

Thanks everyone for the knowledge. It ended up being the fuel pump. But she's running and crawling once again.