Topic: New member, desperately need 2.5 tbi help

[Fahrvegnugen]

Ok first of all I hate being that guy who comes in and posts one tech question but i'll probably stick around because this is a good forum from what ive read and searched, though. I have searched this topic and havent found anything so im here to ask you 4cyl experts.

Vehicle in question is a 90 YJ 2.5 tbi with a manual transmission.
It just plain wont run right it always sputters and dies when you give it moderate to heavy gas, bogs down and chokes at about 2300-3000 rpm when it does run right and diesels very badly when turned off.
Ive replaced a lot of parts on it a small list being
Injector, fuel pump, fuel pressure regulator, intake manifold gasket, tbi gasket, o2 sensor, crank sensor, tps, egr valve, most vacuum lines and the engine was replaced prior to us getting it, had this problem before that old one just blew up.

Since theres little aftermarket support for this motor its been junkyard or nothing. I found an 89 XJ with the tbi motor in it so I took everything related to it, manifolds, tbi and all sensors as well as the valve cover because its a CCV system and the YJ is a pcv system. The XJ tbi only had 2 vacuum nipples in it while the YJ had 4. Does anyone have a good diagram of the tbi ccv system or even a few good pictures of your motor if possible. Of even a way to safely delete the pcv, this vehicle no longer gets smog tested in my state so thats an option to.

I plan on swapping everything from the XJ to the YJ tomorrow so if you have any tips or suggestions of even something else for me to try before i do all this work I'd really appreciate it.

[sharpxmen]

read this thread, should have all the info you need.

http://4bangerjp.com/forums/index.php/topic,9114.0.html

[Fahrvegnugen]

Thanks I saw that one and bookmarked it for future reference already. Mine isnt doing the same as that but close. I was more looking for some info on the XJ setup I have and swapping that in. Doesnt look to hard.

I can eliminate most emissions junk anyway as its not tested.

[chardrc]

you can't delete the pcv system as it is the 1 vacuum related thing that a motor needs for non efi reasons (pcv system vents pressure form crank case that is created by blowby and pistons moving). i basically put everything i know about the vacuum system for the tbi on that thread sharpxmen linked to.

its interesting that the xj tbi only has 2 vacuum ports as the base vacuum diagram i had was form a site that was posting xj stuff and i don't realy see how it could do all the vacuum stuff with 2 less lines. i could see one less because xj at that year didn't have the central axle disconnect. but don't know what the second deleted vacuum line would be unless they had an additional vacuum line come straight from the manifold.

[Fahrvegnugen]

I figured out what the one deleted line was, the thermostatic air control thing in the air box. It gets its vacuum from different places on the different model.

Im pretty sure i figured it out. the XJ intake manifold had a vaccum port in the manifold itself rather then in the tbi unit, its right under the TBI so it makes sense that the diagram on that XJ site you lined showed it there. that is where I believe the PVC line goes to, at least thats my theory