DeCaff2007
I'm Awesome
Ok I guess it's about time I updated everyone as to what's been going on.
For those of you that would like a refresher (or are not up to speed on my last two epic failures, lol....), I have an 88 (89?) RCSB that started life as a 5-speed V6. I swapped a 94 5.7L into it and tried to show off with aluminum heads at the same time. It was a learning experience to say the least.
Where we last left off, I was attempting to learn how to tune a 35 year old PCM with TunerPro RT. It got me absolutely nowhere.
Fast forward to last weekend. I tore those aluminum heads right off and put the factory heads back on. Smooth, seamless install. Only real issues was trying to line up the distributor with the oil pump shaft (because I just cannot see down there). Fired RIGHT up and idled smooth with the first key turn.
Test drive #1. Ran ok but still seemed under powered. No more so with or without aluminum heads. Still overheating, which tanked the oil pressure, which lead to the bucking/backfiring/popping problem again. Fine. Now I can rule out any aftermarket parts and there's going to be much less guess work.
Got it home and noticed that the UPPER radiator hose was ice cold. The LOWER radiator hose about burned the skin off my hand. PROGRESS! Tore the 195° thermostat out and it's seized shut. WTF? Put a 160° thermostat in there and BAM, no more overheating!
No overheating = sorta normal oil pressure, but I'm still getting bucking/backfiring at WOT... and, at LONG LAST, it's finally throwing a code! Never did this ever before. OBD1 code 42 and 43. Electronic Spark Timing error and Knock Sensor error.
Using this flow chart, it lead me to a bad ignition control module in the distributor.
Well, if anyone recalls, the distributor I put in has great reviews from Summit Racing, but many have posted that the ICM is junk and should be replaced. Well, that flow chart and my symptoms just proved them all to be correct. I installed an AC Delco ICM and it DID make a difference in power and WOT bucking, but it's still not right.
Test Drive #2: After the new ICM, I could immediately tell it was running MUCH better. I was easy on it at first until it got up to operating temp. Then, I found a STEEP hill and FLOORED IT. It's got better power, indeed, and no bucking/popping at WOT. Then, I got to the summit of that hill and kept the hammer down in 2nd gear. I hit 6500 rpm and that's when all went to Hell. Engine almost stalled. No power. None. It did recover after a few seconds, so I drove back home to regroup.
Went home and checked the codes again. None. 42 and 43 both disappeared, but I still have a Check Engine light. Oh and btw, all this with under 5 gallons of gas in the tank.
Maybe I'll investigate the knock sensor next.
Regardless, the more I drive this thing, the more I'm getting comfortable with it, and the more I'll work out all the bugs.
Stay Tuned! I'll get this thing running right yet!
For those of you that would like a refresher (or are not up to speed on my last two epic failures, lol....), I have an 88 (89?) RCSB that started life as a 5-speed V6. I swapped a 94 5.7L into it and tried to show off with aluminum heads at the same time. It was a learning experience to say the least.
Where we last left off, I was attempting to learn how to tune a 35 year old PCM with TunerPro RT. It got me absolutely nowhere.
Fast forward to last weekend. I tore those aluminum heads right off and put the factory heads back on. Smooth, seamless install. Only real issues was trying to line up the distributor with the oil pump shaft (because I just cannot see down there). Fired RIGHT up and idled smooth with the first key turn.
Test drive #1. Ran ok but still seemed under powered. No more so with or without aluminum heads. Still overheating, which tanked the oil pressure, which lead to the bucking/backfiring/popping problem again. Fine. Now I can rule out any aftermarket parts and there's going to be much less guess work.
Got it home and noticed that the UPPER radiator hose was ice cold. The LOWER radiator hose about burned the skin off my hand. PROGRESS! Tore the 195° thermostat out and it's seized shut. WTF? Put a 160° thermostat in there and BAM, no more overheating!
No overheating = sorta normal oil pressure, but I'm still getting bucking/backfiring at WOT... and, at LONG LAST, it's finally throwing a code! Never did this ever before. OBD1 code 42 and 43. Electronic Spark Timing error and Knock Sensor error.
Using this flow chart, it lead me to a bad ignition control module in the distributor.
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Well, if anyone recalls, the distributor I put in has great reviews from Summit Racing, but many have posted that the ICM is junk and should be replaced. Well, that flow chart and my symptoms just proved them all to be correct. I installed an AC Delco ICM and it DID make a difference in power and WOT bucking, but it's still not right.
Test Drive #2: After the new ICM, I could immediately tell it was running MUCH better. I was easy on it at first until it got up to operating temp. Then, I found a STEEP hill and FLOORED IT. It's got better power, indeed, and no bucking/popping at WOT. Then, I got to the summit of that hill and kept the hammer down in 2nd gear. I hit 6500 rpm and that's when all went to Hell. Engine almost stalled. No power. None. It did recover after a few seconds, so I drove back home to regroup.
Went home and checked the codes again. None. 42 and 43 both disappeared, but I still have a Check Engine light. Oh and btw, all this with under 5 gallons of gas in the tank.
Maybe I'll investigate the knock sensor next.
Regardless, the more I drive this thing, the more I'm getting comfortable with it, and the more I'll work out all the bugs.
Stay Tuned! I'll get this thing running right yet!
