Help with LT1 startup please
11-22-2008, 10:58 AM
#1
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Help with LT1 startup please 96 LT1 out of Pontiac Firebird, Cold air w/K&N, mid length headers, 2 1/2" into dual 50 series flows 3" out, Computer tune by current performance: lower temp, no emissions, raised idle to compensate for no VSS, VATS deleted, Aeoromotive adj. reg., everything else is bone stock except it is in a 88' Toyota 4 Runner, checked one cylinder 150-60 psi comp.
1. I don't have a tach, but I would guess the motor is idling at about 2000-2500rpm at idle even when the temp gauge hits 180. Seems high is there a way to lower it without cracking into PCM? It doesn't seem like Current performance would set it that high.
2. After I run it for several minutes ( It never goes above 185 on temp) and shut it down it won't start back up until it sits for a while. It will turn over just fine, but won't "light off"....battery at 12.6, charges at 14.8 when running. Sometimes if you give it a little gas just right it will barely catch and start. Fuel pressure is at 43.5.
3. Feels like a lot of moisture coming out of the exhaust, little water droplets in the air..blown head gasket? It has been really cold here in Oregon so hopefully it is condensation that was sitting i in the exhaust.
It seems to rev fine, no visible vacuum leaks, when it sits for a while it starts just fine. Possibly leaky injectors? Ideas?
1. I don't have a tach, but I would guess the motor is idling at about 2000-2500rpm at idle even when the temp gauge hits 180. Seems high is there a way to lower it without cracking into PCM? It doesn't seem like Current performance would set it that high.
2. After I run it for several minutes ( It never goes above 185 on temp) and shut it down it won't start back up until it sits for a while. It will turn over just fine, but won't "light off"....battery at 12.6, charges at 14.8 when running. Sometimes if you give it a little gas just right it will barely catch and start. Fuel pressure is at 43.5.
3. Feels like a lot of moisture coming out of the exhaust, little water droplets in the air..blown head gasket? It has been really cold here in Oregon so hopefully it is condensation that was sitting i in the exhaust.
It seems to rev fine, no visible vacuum leaks, when it sits for a while it starts just fine. Possibly leaky injectors? Ideas?
11-22-2008, 12:21 PM
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MAF is hooked up correctly, far as I know. It is farther away from the motor than normal, but sealed up and plugged in.
Engine is pulling 20psi of vacuum at this high idle.
I Don't have a scanner or a OBDII diagnostic port installed yet. If I can find one in a wrecking yard today I'll put one in. Can I rent a scanner or buy a cheapo that is decent. What does it take to use a laptop to check codes? I'd like to check the cheap and easy ways first.
I will check the IAC if I can find a good way using a multimeter. I believe the manual had something about checking the resistance .54 or 54 ohms or volts..can't remember, but I'll check it out.
Other ideas?
Engine is pulling 20psi of vacuum at this high idle.
I Don't have a scanner or a OBDII diagnostic port installed yet. If I can find one in a wrecking yard today I'll put one in. Can I rent a scanner or buy a cheapo that is decent. What does it take to use a laptop to check codes? I'd like to check the cheap and easy ways first.
I will check the IAC if I can find a good way using a multimeter. I believe the manual had something about checking the resistance .54 or 54 ohms or volts..can't remember, but I'll check it out.
Other ideas?
11-22-2008, 03:25 PM
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Tested the IAC with info found on another post...Good to go.
Sprayed carb cleaner everywhere I thought there could be a vacuum leak while running. Nothing... idled the same so no vacuum leak.
Will start 10 times in a row until you get it warm..then cranks like crazy, but won't light off. ICM or coil? Read about the coil getting to warm to provide sufficient spark in another post. Is this a likely possibility?
Maf is hooked up and working, if I start it without it plugged in it starts and dies, if I pull it while running it dies. Plugged in it runs, just idles high.
Sprayed carb cleaner everywhere I thought there could be a vacuum leak while running. Nothing... idled the same so no vacuum leak.
Will start 10 times in a row until you get it warm..then cranks like crazy, but won't light off. ICM or coil? Read about the coil getting to warm to provide sufficient spark in another post. Is this a likely possibility?
Maf is hooked up and working, if I start it without it plugged in it starts and dies, if I pull it while running it dies. Plugged in it runs, just idles high.
