1993 XJ motor with issues... could use some sound advise !

Hi and thanks for having me onboard… I’m a LONG time Jeep guy from with tendencies towards XJ’s and Yj’s . I’m having some difficulties with a motor and was hoping for a little sound advise.

Here is what I’m working with:

1989 YJ with a MOTOR/ ECM/TCM/ Tranny swap

1993 XJ 4.0 motor and ECM
1998 AW4 and TCU
All wiring crossed over and working great FYI


HERE’S THE ISSUES


The 4.0 misses at midrange RPM.. (2 grand ish) and I noticed last night that THE EXHAUST MANIFOLD TURNED CHERRY RED AND GLOWING. Nothing past the exhaust manifold gets discolored and the overall temp of the motor stays around 210 degrees (gauge). Here’s what’s new on the Jeep for troubleshooting purposes and remember all these parts prolly have less than 2 miles of driving on them

Let me add that I’m not certain that it wasn’t always doing this ….. I just noticed it last night …

New parts:

• New valve cover gasket
• New Exhaust manifold
• New water pump
• New water inlet
• New thermostat
• New Radiator
• New fuel pressure regulator
• New belt
• New plugs
• NEW sensors ( Idle air control, Throttle position (as of last night), Crank position sensor, MAP sensor, temp sensor, O2 sensor)
• New complete exhaust (down pipe, cat, muffler and tubing)… NEW gaskets as well (exhaust manifold to block)
• New to ME injectors
• New to Me fuel rail
• Replaced all the vacuum lines
· New Cap
· New rotor
· New plug wires


I pulled the injector rail last night and noticed that I have the XJ injector (part # RL030778AB) that according to the web have a flow rate of 49 psi / 23.2 and is technically for a 1996 XJ… does this matter ??? I notices that the fuel pressure regulator for years 1993 thru 1996 is the SAME ….


ANY ideas as to where to start would be awesome….

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.