cheekychimp
Well-known member
I know there is a whole load of information in the VFAQ on this. I've been through there once (can't say I understood it all though) and back through some of the threads in here and the archives trying to find stuff to attack next.
Cliff notes so far are that the car does not idle correctly. There is some idle surge, although to be honest it is minimal. The idle won't however remain steady and ends up far too high after cruising for a period of time. The biggest issue is that 'blipping' the throttle causes the engine to stall. This happens at junctions, but it also happens at very low loads i.e. slightly raising the RPMs just backing the car into a parking space.
A few issues to deal with. This is a 1990 JDM car, currently running a USDM 1G DSM ECU with the original 1990 harness.
Issues we have dealt with so far: -
(1) Swapped Pins 6 and 14 in the 1990 harness to match the current ECU;
(2) Removed DSMLink and replaced with a chip Jeff burnt me for my setup to eliminate any issues relating to my lack of tuning prowess;
(3) Installed an AFPR since I had previously been unable to install my fuel rail which has the AFPR integrated. Fuel pressure is currently set to 43.5 psi which corresponds to the settings in the chip that Jeff burnt for me;
(4) Reset BISS after grounding the connector at the firewall and connecting the DSMLink cable to the OBD1 connection port under the dash.
Given what I have read from the VFAQ and talking to a few guys, future things on the list to examine are: -
(A) Vacuum leaks (need to make up a tester and pressure test the intake)
(B) Get a logger and check TPS position
(C) Idle closed switch
(D) Re-circulate BOV (not convinced this is the issue at idle but it's an easy fix and needs to be done anyway!)
So my questions are
1. Apart from the obvious loose couplers, where might I find leaks? (BOV, throttle body ... any others?)
2. Can someone tell me step by step how to calibrate the TPS? Apparently the VFAQ is wrong.
3. How do I check the Idle closed switch? I also remember something about having to ground it properly?
4. What is it that I am grounding exactly when I reset the BISS? I have the connector at the firewall located but is plugging a logger cable or the DSMLink cable in at the OBD1 port necessary/sufficient?
5. Anything else I should check out?
Thanks to Yiuwa for his help so far.
Cliff notes so far are that the car does not idle correctly. There is some idle surge, although to be honest it is minimal. The idle won't however remain steady and ends up far too high after cruising for a period of time. The biggest issue is that 'blipping' the throttle causes the engine to stall. This happens at junctions, but it also happens at very low loads i.e. slightly raising the RPMs just backing the car into a parking space.
A few issues to deal with. This is a 1990 JDM car, currently running a USDM 1G DSM ECU with the original 1990 harness.
Issues we have dealt with so far: -
(1) Swapped Pins 6 and 14 in the 1990 harness to match the current ECU;
(2) Removed DSMLink and replaced with a chip Jeff burnt me for my setup to eliminate any issues relating to my lack of tuning prowess;
(3) Installed an AFPR since I had previously been unable to install my fuel rail which has the AFPR integrated. Fuel pressure is currently set to 43.5 psi which corresponds to the settings in the chip that Jeff burnt for me;
(4) Reset BISS after grounding the connector at the firewall and connecting the DSMLink cable to the OBD1 connection port under the dash.
Given what I have read from the VFAQ and talking to a few guys, future things on the list to examine are: -
(A) Vacuum leaks (need to make up a tester and pressure test the intake)
(B) Get a logger and check TPS position
(C) Idle closed switch
(D) Re-circulate BOV (not convinced this is the issue at idle but it's an easy fix and needs to be done anyway!)
So my questions are
1. Apart from the obvious loose couplers, where might I find leaks? (BOV, throttle body ... any others?)
2. Can someone tell me step by step how to calibrate the TPS? Apparently the VFAQ is wrong.
3. How do I check the Idle closed switch? I also remember something about having to ground it properly?
4. What is it that I am grounding exactly when I reset the BISS? I have the connector at the firewall located but is plugging a logger cable or the DSMLink cable in at the OBD1 port necessary/sufficient?
5. Anything else I should check out?
Thanks to Yiuwa for his help so far.
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