I have an 88 xj, everything is modified... everything. I have a HO4.0 using all of my renix sensors, everything was going good then the other day it started acting all wierd, it would barely run. So I get it home and get her goin and i have to crank it for 15 minutes before it will start. after it is started and warmed up, it will start right back up and runs perfect when I try to start it cold it makes me want to strike a match...

 

Go to the link in my signature and do a CPS test # 7.

Ever checked your fuel pressure? Clean your C101? Ground refreshing?

 

Did all of the above. I replaced fuel pump, pressure is still low. Cleaned all the connectors and direct wired the CPS. It started better it is still lacking power tho but much better than it was. Thank you for your help

 

Ever do a check for clogged/restricted exhaust with a vacuum gauge?

CRUISER’S VACUUM TEST FOR EXHAUST RESTRICTION

Your vacuum gauge should come with an instruction booklet outlining the procedure. Hook the vacuum gauge up to a source on the intake manifold. Start the engine and note the vacuum reading. Usually 17 to 21 inches of vacuum. Throttle the engine up to 2,000 to 2,500 RPM for 20 seconds or so and the vacuum reading should stabilize to the same reading you got at idle. Let the throttle snap shut. The vacuum reading should shoot up about 5 inches of vacuum higher for a second and then come quickly down to the original reading. If the vacuum reading stays high and comes down slowly with jerky needle movements, you have an exhaust restriction.

 

When you shut the engine off will it hold fuel pressure in the rail?

 

The pressure never did reach 39 it only went to 28, it did hold however. I went outside this morning and no start again. there was a HEAVY smell of gasoline tho.

 

Yesterday, i did all of the things you suggested. no start this morning. i wired the cps to the computer and still no start

 

That's kinda low.