aggiez32
03-20-2006, 10:49 AM
Okay, I've done a ton of searching and I'm still having major problems determining what is wrong with this car. Here's a background on everthing we've done:
1990 240 5-Speed
1991 KA24DE
Rebuilt from block-up
Honed block, new rings, new bearings
Milled head
New valve seals
New timing components
Timing set correctly to account for exhaust cam in intake position
New Nissan NGK plugs
Good coil/wires - Tested Spark
Using original 5-speed tranny/alt. harness from SOHC Car
Using Automatic engine harness from DOHC Car
Using Throttle body & TPS from Automatic DOHC car
Eliminated EGR with new gasket and blockoff plate
Elimitated vacuum plate from the back of the head
T-d from FP Regulator to butterfly valve to the vacuum port on the intake manifold
Retained SOHC carbon canister - Vacuum source is throttle body, purge source should be the same line as the DOHC
IACV vacuum line hooked to intake
Valve cover vented to intake
Okay, so here's the problem:
Car started up right away, no problems there. The problem is the idle. It starts at 1250 and revs to 2500, then drops back down. This repeats over and over and over with no delays. When you rev, it will drop down for a second, but then continue the cycle. We need to get the idle steady so we can set timing. At these revs, we "set timing" to 20 BTDC, but the car runs like ass. Stumbles and really has no power. I'm assuming it's just because the idle / distributor timing are set incorrectly.
We sprayed tons of carb cleaner into the tube that runs to the IACV, but it didn't have any affect. We can't tell that we have any vacuum leaks. We've sprayed carb cleaner around and it makes no change in the idle. We've re torqued the bolts on the intake manifold.
We tried the FSM's method for setting the base idle, but it doesn't seem to have any affect. When we unplug the TPS, the car revs to 4k+.
We need this car running, any suggestions would be great. Here's what we're going to try so far.
Different MAF
Different TB & TPS
Different IACV
Other than that, we're stumped. Most of the IACV problems we've seen are due to low idles that cause the car to stall out, so I'm not sure that's our problem.
Help please!
1990 240 5-Speed
1991 KA24DE
Rebuilt from block-up
Honed block, new rings, new bearings
Milled head
New valve seals
New timing components
Timing set correctly to account for exhaust cam in intake position
New Nissan NGK plugs
Good coil/wires - Tested Spark
Using original 5-speed tranny/alt. harness from SOHC Car
Using Automatic engine harness from DOHC Car
Using Throttle body & TPS from Automatic DOHC car
Eliminated EGR with new gasket and blockoff plate
Elimitated vacuum plate from the back of the head
T-d from FP Regulator to butterfly valve to the vacuum port on the intake manifold
Retained SOHC carbon canister - Vacuum source is throttle body, purge source should be the same line as the DOHC
IACV vacuum line hooked to intake
Valve cover vented to intake
Okay, so here's the problem:
Car started up right away, no problems there. The problem is the idle. It starts at 1250 and revs to 2500, then drops back down. This repeats over and over and over with no delays. When you rev, it will drop down for a second, but then continue the cycle. We need to get the idle steady so we can set timing. At these revs, we "set timing" to 20 BTDC, but the car runs like ass. Stumbles and really has no power. I'm assuming it's just because the idle / distributor timing are set incorrectly.
We sprayed tons of carb cleaner into the tube that runs to the IACV, but it didn't have any affect. We can't tell that we have any vacuum leaks. We've sprayed carb cleaner around and it makes no change in the idle. We've re torqued the bolts on the intake manifold.
We tried the FSM's method for setting the base idle, but it doesn't seem to have any affect. When we unplug the TPS, the car revs to 4k+.
We need this car running, any suggestions would be great. Here's what we're going to try so far.
Different MAF
Different TB & TPS
Different IACV
Other than that, we're stumped. Most of the IACV problems we've seen are due to low idles that cause the car to stall out, so I'm not sure that's our problem.
Help please!