I bought a single turbo with a blown motor. With the new motor swapped in, and a techedge wideband attached, the following symptons are observed:

1. Cold start, car sounds like it's on one rotor only. Very lumpy idle. 3 to 4 minutes later, idle is perfect. Compression is around 100pis on all faces. I've removed the secondary butterfly and I've machined away the materials separating the two chambers that used to hold the secondary butterlies.

2. A/F -- car idles at full rich 10.5. This is when things get weird. For the first 20 to 30 minutes after I started the car, it refuse to accelerate in any gear above 4000rpm. A/F would show full lean above 18. There's no fuel going into the engine!

After approximately half an hour of driving, the A/F will steady at around 10.5 to 11 and suddenly it goes like a rocket boosting up to 1 bar on the TD06-25Gs. Nonetheless, fuel behavior is still unpredictable but never backfires and never stalls. Perfect idle.

3. The car's mod includes TD06-25G, Denso external fuel pump of unknown capacity but it's twice the size of a Walten 255l. Fuel regulator with gauge that looks like the OBIX aluminium billet eBay item with a guage attached. Stock 550 and 850cc. Fuel pressure is around 2 bar at idle and holds for 10 min or more after engine's switched off. Fuel pressure rises to 5 bar when I rev the engine while not in gear. RE Amemiya ECU with a sticker that wants me to believe it's factory tuned by Amemiya for the TD-6-25Gs. Air pump removed, EGR removed. secondary butterly removed, ACV removed, all ICE removed.

4. Strange whooooo noise indicating a leak from the intake area.

5. Things I've checked:- intake air temp sensor okay, TPS works okay but voltage not exactly in range (perhaps need a more precise meter), MAP sensor is about 0.4 volt out of range from factory spec (TPS position not properly adjusted yet, coolant level sensor not checked)

Does this sound like an ECU problem or an air leak problem or problem with the TPS, or other sensors such as the bar sensor or the TPS?

 

Problem mysteriously went away tonight and she ran like a champ except for an exhaust leak. After ownership of 3 RX7s, I've finally got one that runs right, doesn't overheat and doesn't lose coolant !!!!!!!!!!! It's a miracle and I finally get to enjoy the 7 as its designers intended!

 

Ever figure out what the problem was?