Jakenfire

So I am the proud new owner of an 87 XJ 4.0 5sp. She has about 250k on the clock and of course has a few problems here and there.

When im taking off in first gear, if I ease the throttle and let the clutch out (as I normally would) the engine wants to cut out at about 1k rpm. This doesn't seem to happen all the time but does happen for sure about 95% of the time. However if I give it a little more gas and bring it up to about 1500 before letting the cluth out slowly, it does fine. Also when there is no load, it has no issue. It only has the problem when under load. What could this be??? I think with that many miles the timing chain may need some attention, it kinda sounds a little loose. It is also missing the vaccume line from the fuel pressure reg. Where is that supposed to go??

Also wanted your opinion on where the best place to get parts is?

Thanks for your help.

Bustedback

The fuel pressure regulator should have manifold vacuum. If the line is off, you're running at full fuel pressure when you don't need to be, like 1000rpm when you're taking off from a dead start.

Jakenfire

Awesome thank you. I'll run a line for that asap. Sounds like that could save me some MPGs. I did run a temporary line from the manifold just to see if that would fix the stalling issues but it didn't. So now I know that can't be it.

Thanks for the input! One problem down about a thousand to go!

Gee oh Dee

I'd say do normal maint. Plugs, wires, cap, rotor, etc. Bad plugs can cause subtle issues like the one you are talking about.

As for the vacuum issue, if the FPR isn't getting the propper signal, it could cause fuel issues, and may be delivering incorrect amounts of fuel at idle and lower RPMs.

Jakenfire

I guess I should have mentioned that I did the the standard tuneup items. So plugs, wires, cap and rotor are new.

Jakenfire

Should i be able to tell a difference when the FPR is hooked up to vacuum?

Caish

Google search: Renix FI Manual pdf
You will find it most useful.

Jakenfire

awesome thank you.

Molinaribp

i had that problem too and it was the o2 sensor, no idea why but replacing it fixed it

Jakenfire

thanks. ill give that a try. i have a pretty good handful of things that need to be done. ill have to add that to the list.

84zmyfavorite

The Renix Fuel Injection Manual is very good. Almost 100 pages of goodness.

Jakenfire

i agree, what an amazing resource. i just spent the last hour reading through it.


so now that i have a pretty good parts list, where is the best place for me to get them??