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"The engine light came on..." says my bride when I walk in the door after work New Years Eve.
The daylight is about gone and a light drizzle helps the cold penetrate as I get the codes from the LH2.4 computer on this 1989 245GL metallic blue-green: 113 and 232 - injector problem; compensating for too lean or too rich mixture. A couple whiffs tell me it's a rich mixture. I pull the AMM hose and open the throttle to a knock-you-over smell of raw gas.
I shiver and recall Smitty's "Fruit of the loom" moment post and shut off the motor before pulling the FPR vacuum hose. Smells iffy. Well, I've never sniffed one with gas running through it from a broken diaphragm, and I still smell the rich fumes from throttle body. It's dark now, I want to check the pressure but I'm a wimp and decide to wait for daylight.
Rains all day yesterday. Good, we don't need the car anyway on New Years Day.
Tonight, home a little earlier, I get my gauge on the fuel rail to make sure the FPR is OK and the injectors aren't leaking. Solid 40 pounds, up to 43 referenced to atmosphere. Walk away for 15 minutes, come back, still 40 lbs.
Thinking ECU... AMM... ECT...
Put meter on the O2 sensor - warms up to 830 mV and sticks there. Stays there even through throttle blips and reducing rail pressure to 35 lbs using a vacuum tester on the FPR. This thing is dumping the gas in. Yes, the oil stick looks a tad over full!
Found novel (to me) lazy way of depressurizing the rail - to disconnect the gauge. The OBD will cycle the main injectors for testing (three 1sec. presses), so in the time it took me to check the sound from each injector the fuel pressure had relieved to about 10 lbs. Not that much gas, but I'll still change the oil this weekend. I didn't try this, but maybe you could, by connecting one injector at a time, identify a grossly clogged unit watching the gauge as the computer cycles the test.
Took the gauge off and pulled the ECU connector to check the ECT. Looked good, about 480 ohms at pin 13 and rising as the engine cooled some. Pretty much left two items, ECU and AMM.
Having an 89, I learned early reading this board to have an ECU spare. Found one in the pick and pull about a year ago in a 92, but it was a -561, supposedly the unreliable model. The 89 has a -933 (yes 933) so I figured I might never need my spare.
Popped out the 933 and put the 561 in. O2 sensor now shows nice even transitions rich/lean and no more codes are being set. This forum and you all have saved my bacon again! Smells better already. My customer cooked dinner for me and that smelled even better.
Looked at the 933 - there's a bit of epoxy charring under R15 - some melted solder at its leads... well that will be another post if I learn anything.
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Art Benstein near Baltimore
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