blackdeathmessenger
OBS Enthusiast
Right. Well, I didn't just swap chips, I swapped the entire computer without opening it
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Do you know where this ECM came from? Was it the same engine size, trans, rear end gears, etc? Just because the connectors plugged in, doesn't mean they're all pinned to the same locations.Well, I didn't just swap chips, I swapped the entire computer without opening it
These are not camshaft problems. Try pinching off the vacuum hose to the brake booster and see if that affects your idle.One of the biggest issues, is, and has been, the idle. It keeps surging/searching for the idle. I also have less vacuum, which I can definitely feel in my brake pedal, and most recently, I've had issues with extended cranking time before starting and now when it does start, I have to hit the gas and rev the engine to get it up to normal idle... The only thing that makes sense after all my checking and testing is the camshaft.
Well...could be camshaft "degree" issues; cam is not properly synched with the crank. This is why I spend the time with the degree wheel and dial-indicator EVERY time I install a cam.These are not camshaft problems.
I'd pinch every vacuum hose, one at a time. The only one that should affect idle is the PCV suction hose. I remember from decades ago, GM had problems with the canister purge valves. They'd affect idle quality, but they also screwed-up driveability and fuel economy, too.Try pinching off the vacuum hose to the brake booster and see if that affects your idle.
These could easily be camshaft problems, like if a lobe goes flat, or the cam timing changed suddenly, for example. I've had a chain skip teeth while I was driving it. That was not a fun experience to get it homeThese are not camshaft problems. Try pinching off the vacuum hose to the brake booster and see if that affects your idle.
Sadly, I wasn't the one that built this engine since I didn't have time to do so with how much I was working at the time (a couple years ago). I've tried doing the pinch off thing with the vacuum lines, it didn't reveal anything new. With how it's running, it's hard to narrow down, aside from a possible computer issue, as pointed out by PlayingWithTBIWell...could be camshaft "degree" issues; cam is not properly synched with the crank. This is why I spend the time with the degree wheel and dial-indicator EVERY time I install a cam.
A compression test might reveal gross cam-timing errors.
Depending on how fast the lifters bleed down, putting a cylinder on TDC-Exhaust (NOT TDC-Compression) and looking to see that the intake valve is farther open than the exhaust valve would be an excellent indication.
I'd pinch every vacuum hose, one at a time. The only one that should affect idle is the PCV suction hose. I remember from decades ago, GM had problems with the canister purge valves. They'd affect idle quality, but they also screwed-up driveability and fuel economy, too.
If it's an 88 with an automatic trans odds are, you should have a 1227747 ECM.What numbers should I be looking for, for compatibility?
So, it is indeed a 1227747 ecm. The .bin showing on the case and prom is ARJT, with number 7409 below it if that mattersIf it's an 88 with an automatic trans odds are, you should have a 1227747 ECM.
Here's one, you can see the service number and .bin (ANLW) on the sticker but, you should pull the cover and look at the chip itself hopefully to confirm which one you have. In this picture I have a ZIF socket with a flash chip in that spot.
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Your BCC (AKCW here) should look like the one on the right here in its plastic holder.
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Once you find out what you have, post it here and we'll look it up.
OK, that .bin is for a 5.7L, 700R4 trans so, it MAY not be a source of your issue.it is indeed a 1227747 ecm. The .bin showing on the case and prom is ARJT, with number 7409 below it if that matters