My 2.0 D-Jet motor runs hot,, Edit - idle fixed, vacuum leak found Options

[Cevan]

I swapped out my 1.8 L-jet motor for a stock 2.0 D-Jet motor. I’ve put about 75 miles on the car since the engine swap. According to my CHT gauge, it seems to be running hot. I had a similar problem with the old motor. That engine was running lean and I adjusted the AFM and got it to run around 325-350 on the highway (70-75 mph).

The 2.0 motor runs around 350 in 3rd or 4th gear at 3000 rpms and goes up from there when it’s on the highway. The gauge is definitely reading hotter temps across the board compared to the 1.8 motor.

The only issues I have currently are a minor vacuum leak (idle is a bit high) and a TPS that is a bit worn. The car runs great otherwise. It accelerates nicely (noticeable improvement over the 1.8).

All the tin is in place, fan is intact, no blades missing. Dwell and timing are correct. Valves adjusted. Injectors cleaned and tested. MPS good and is the correct one for a ’74 2.0 motor. New points, cap, rotor, plugs, plug wires, vacuum lines.

I need to pull a plug and see if I see signs of it running lean. This is what I suspect. I will also check the fuel pressure. Could this be a timing issue? Could it run cooler at a different timing setting than the factory spec? Any thoughts? (IMG:style_emoticons/default/confused24.gif)

I also can't get the idle below 1300 rpms. I have the idle adjustment screw all the way in and when I go to turn the idle mixture screw on the ECU CCW to get it below 1300-1400 rpms, it does this up and down thing with the revs. I've sprayed of starter fluid at every place a vacuum leak might exist and the revs don't change. I'm this close to putting L-Jet on the damn thing.

[Cevan]

Quick update: car still runs hot and no idle below 1400 rpms. No vacuum leaks were noted using the starting fluid method. This method did find vacuum leaks at the intake to head junction and at the cold start valve. I fixed these and now no changes to rpms are noted when I sprayed the starting fluid.

Timing was a bit off but once that was adjusted, no change in temps. I also drove it with the fuel pressure at 35 psi and no change. I also flipped the plug of the MPS around and no change.

I will re-confirm the accuracy of the gauge with an infared thermometer. I will also try a couple of other plugs for #3 just to see what happens. I have a Bosch W7CC. I will also try an NGK B7ES

Rich - I adjusted the valves before I put the motor in about 100 miles ago so I think that is taken care of. The CHT is the correct one and is within spec.

I will try and get a hold of a different MPS. Mine holds vacuum but I'm not sure if something else is going on with it that would cause the motor to run lean.

If all of this fails, I'll slap the L-Jet on it. Hell, isn't that what Porsche did with the 912E? (IMG:style_emoticons/default/wink.gif)

On a positive note, no oil leaks after replacing all the seals.