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Hi All,
I have had a 82 245 with the LH1 Jetronic injection system for the last 9 years. It's been amazingly reliable and efficient, however, since the injectors are expensive and more prone to failure due to their design, I had the bright idea to swap out an intake manifold + injectors & fuel rail from a later model 240.
First a little background: The 82 LH1 manifold has a cold start injector (just like K-Jet B21Fs with the thermal time switch). The 90 and later manifolds also have a place for a cold start injector, unlike the mid and late 80s 240s with LH2+ jetronic didn't have the CSI. Also, all intake manifolds from B21, B23 and B230 are compatible. Another difference is the 90 manifold has a port for what appears to be EGR.
A few weeks ago I found and pulled an intake from a donor 90 245. After removing my original manifold and cleaned up everything below, I discovered a wiring harness that was about to go up in smoke. So I went back to the pull-and-pay and pulled the engine harness from the same donor 90 245, rebuilt my harness with the donor and finally reinstalled everything. The other challenge was the hose running to and from the IAC. on the B230F engine, the IAC actually makes a 90 turn in the device, where as on the 82, the connections are 180 degrees apart (straight through). One more task that I have not done yet is to wire in the TPS from the newer throttle body (the 82 LH1 uses a vacuum actuated switch to determine throttle position.
Surprisingly there were only two glitches initially- A vacuum leak from the IAC hose and a loose connection to the hall sensor. Once I resolved the two issues, it starts and idles smooth.
Now that I'm driving it, I've found that MPG seems to have gone down (<20mpg). Also the idle seems to be high (probably an issue with the vacuum operated TPS). I re-set the timing to 12deg, but no real change in performance. I've just tried adjusting the CO setting on the AMM (leaning out, 1 revolution clockwise) but haven't checked to see if MPG improved yet.
Based on the part numbers I have checked, the FPR has the same pressure setting as the original (3 bar, I believe) and the flow rates of the 90's injectors are almost exactly the same as the original LH1 injectors. So I do not suspect it is delivering significantly more fuel compared to the original system.
Anyway, I just thought some might find interest in this. If anyone wants more specifics on the process to update your LH1 system, let me know :-)
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'82 245 B21F-MPG-LH 1.0, '83 244 B21FT-K-Jet, '86 244 B23F-LH 2.0
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