LT1 Swap problems, not running right, Please help
Thread Starter
Registered User
Joined: Jul 2007
Posts: 198
From: Norton, MA
LT1 Swap problems, not running right, Please help
Hi I am swapping my second LT1 into a 76 Datsun 280Z, my first motor developed a rod knock before I ever got it off the jack stands.
Not to be defeated I bought an Ironhead LT1 out of a Fleetwood to use temporarily while I would tear down and rebuild the Trans AM LT1 I had in there at first.
Well the ironhead LT1 is running kind of. I had to swap out a brand new Opti with my MSD Opti off the Trans AM LT1 to get it started. There was no continuity on the brand new cap from the coil wire feed to the rotor button. I'm getting good at Opti swaps, done in 2 hours.
Now for the problem:
It runs like crap, #3 and #4 cylinders are not firing for some reason, this is what I have done so far:
1. put a spark tester on each spark plug wire, all test ok
2. Resistance check each injector, all test ok
3. apply 12 volts to each injector, some were stuck but all were clicking after tapping each solenoid with 12V they were all clicking.
4. bought a NOID light kit, all tested OK as receiving the negative pulses.
5. Fuel pressure is right at 45Lbs while running although bleeds right off. I found out I need to hook the Air bleed line in with the return, I will get this done after my AN adaptor and "T" fitting get here today.
6. Bought a compression gauge and removed all the spark plugs and did a compression check the results were:
Cylinder #1 200Lbs
Cylinder #2 195Lbs
Cylinder #3 200Lbs
Cylinder #4 190Lbs
Cylinder #5 200Lbs
Cylinder #6 193Lbs
Cylinder #7 190Lbs
Cylinder #8 204Lbs
Now after testing and putting the plugs back in I noticed that I forgot to wire the throttle wide open during the test. Each cylinder would increase it's pressure on each rotation.
7. While I had each brand new plug out I looked at them and all 6 plugs that had fired were black with a grey tip, the #3 and #4 cylinder looked like they had never fired, a little slight dis-colorization but that was it.
8. I went to hook up my Autoxray XP240, but half the LCD screen was not working so I couldn't read half of what it was reading in capture mode.
My Son had borrowed it and now it doesn't work, what else is new!
A few days earlier it read the following codes:
#43 Electronic Spark Control
#29 EAS Electrical Failure
#91 Shift Light Fault
#97 4K Pulse mile fault
The capture read:
Loop-Open
800 Idle
800 RPM
166.5 coolant
86.9 Manifold air
MAP 1.33V
Throttle 0.56
Throttle angle 0%
Mass 10gr/sec
CCP duty cyc 0.0
Battery 1.6V
BAR Pressure 4.90
Left O2 83
Right O2 193
Bl cell 16
Left block value 128
right block value 128
Integra value 128
Left Injector pulse 4.2ms
Right Injector pulse 4.2ms
Idle air meter 44 steps
Learned Idle 32 steps
Spark advance 22 degrees
Knock retard 0
Knock Sensor 245
EGR 0.0%
Fan 1 on
Fan 2 on
Air switch off
Last night I ran it longer to see if it would go into Closed loop and used the laptop with PCM Communicator.
Closed loop
Water temp 173
RPM 775
RPM Variation 1.66%
Air flow 9gm/sec
Desired Idle 800
Left O2 249mV
Right O2 688mV
Throttle position 0%
Left O2 BLM 128
Right O2 BLM 128
Left O2 Del 138
Right o2 Del 138
Battery 12.6V
TPS volts 0.57
IAC Pos 28
Baro 102kpa
In air temp 80F
Learn disabled
Spark 23 degrees
Knock retard 0.0
Knock count 9905
MAP 33kpa
Left pulse width 4.75ms
Right pulse width 4.82ms
BL Cell 16
Gerr -1
Input trans mode-performance
Input no TCC brake sw
Input no spark retard
Not power enriched
no kickdown pattern
no injector fault
both fans
3rd gear
A/C temp 40
A/C pressure 0.02V
Again I have a these 2 codes:
Code 29 EAS Electrical Fault (ODM)
Code 43 ESC failure
I can erase these 2 codes but the keep coming back,
My factory manual say that code 29 is an air pump code
and code 43 is a knock sensor code?
Both scanners say the same code number but a different description than the manual???
I did replace the Knock sensor, and I have exhaust leaks with the Sanderson headers, I need to install gaskets.
How much harm am I doing to the motor by running it on 6 cylinders?
What would cause cylinders 3 & 4 not to fire?
Sorry for the long post, but I wanted to get all the information down.
Thanks,
Greg
Not to be defeated I bought an Ironhead LT1 out of a Fleetwood to use temporarily while I would tear down and rebuild the Trans AM LT1 I had in there at first.
Well the ironhead LT1 is running kind of. I had to swap out a brand new Opti with my MSD Opti off the Trans AM LT1 to get it started. There was no continuity on the brand new cap from the coil wire feed to the rotor button. I'm getting good at Opti swaps, done in 2 hours.
Now for the problem:
It runs like crap, #3 and #4 cylinders are not firing for some reason, this is what I have done so far:
1. put a spark tester on each spark plug wire, all test ok
2. Resistance check each injector, all test ok
3. apply 12 volts to each injector, some were stuck but all were clicking after tapping each solenoid with 12V they were all clicking.
4. bought a NOID light kit, all tested OK as receiving the negative pulses.
5. Fuel pressure is right at 45Lbs while running although bleeds right off. I found out I need to hook the Air bleed line in with the return, I will get this done after my AN adaptor and "T" fitting get here today.
6. Bought a compression gauge and removed all the spark plugs and did a compression check the results were:
Cylinder #1 200Lbs
Cylinder #2 195Lbs
Cylinder #3 200Lbs
Cylinder #4 190Lbs
Cylinder #5 200Lbs
Cylinder #6 193Lbs
Cylinder #7 190Lbs
Cylinder #8 204Lbs
Now after testing and putting the plugs back in I noticed that I forgot to wire the throttle wide open during the test. Each cylinder would increase it's pressure on each rotation.
7. While I had each brand new plug out I looked at them and all 6 plugs that had fired were black with a grey tip, the #3 and #4 cylinder looked like they had never fired, a little slight dis-colorization but that was it.
8. I went to hook up my Autoxray XP240, but half the LCD screen was not working so I couldn't read half of what it was reading in capture mode.
My Son had borrowed it and now it doesn't work, what else is new!
A few days earlier it read the following codes:
#43 Electronic Spark Control
#29 EAS Electrical Failure
#91 Shift Light Fault
#97 4K Pulse mile fault
The capture read:
Loop-Open
800 Idle
800 RPM
166.5 coolant
86.9 Manifold air
MAP 1.33V
Throttle 0.56
Throttle angle 0%
Mass 10gr/sec
CCP duty cyc 0.0
Battery 1.6V
BAR Pressure 4.90
Left O2 83
Right O2 193
Bl cell 16
Left block value 128
right block value 128
Integra value 128
Left Injector pulse 4.2ms
Right Injector pulse 4.2ms
Idle air meter 44 steps
Learned Idle 32 steps
Spark advance 22 degrees
Knock retard 0
Knock Sensor 245
EGR 0.0%
Fan 1 on
Fan 2 on
Air switch off
Last night I ran it longer to see if it would go into Closed loop and used the laptop with PCM Communicator.
Closed loop
Water temp 173
RPM 775
RPM Variation 1.66%
Air flow 9gm/sec
Desired Idle 800
Left O2 249mV
Right O2 688mV
Throttle position 0%
Left O2 BLM 128
Right O2 BLM 128
Left O2 Del 138
Right o2 Del 138
Battery 12.6V
TPS volts 0.57
IAC Pos 28
Baro 102kpa
In air temp 80F
Learn disabled
Spark 23 degrees
Knock retard 0.0
Knock count 9905
MAP 33kpa
Left pulse width 4.75ms
Right pulse width 4.82ms
BL Cell 16
Gerr -1
Input trans mode-performance
Input no TCC brake sw
Input no spark retard
Not power enriched
no kickdown pattern
no injector fault
both fans
3rd gear
A/C temp 40
A/C pressure 0.02V
Again I have a these 2 codes:
Code 29 EAS Electrical Fault (ODM)
Code 43 ESC failure
I can erase these 2 codes but the keep coming back,
My factory manual say that code 29 is an air pump code
and code 43 is a knock sensor code?
Both scanners say the same code number but a different description than the manual???
I did replace the Knock sensor, and I have exhaust leaks with the Sanderson headers, I need to install gaskets.
How much harm am I doing to the motor by running it on 6 cylinders?
What would cause cylinders 3 & 4 not to fire?
Sorry for the long post, but I wanted to get all the information down.
Thanks,
Greg
Thread Starter
Registered User
Joined: Jul 2007
Posts: 198
From: Norton, MA
Well I am going to put my guess on 2 bad injectors for now, I'll keep everybody posted.
Shoebox just answered my Code 29 question as me needing to put a fuse in and the relay back in at the fuse box...as long as these connections weren't wires I deleted...Then I need to figure out which pin/wire on the ECM needs to be tricked to thinking it is still there....
Oh Yeah, More fun!
Thanks,
Shoebox for the info
Greg
Shoebox just answered my Code 29 question as me needing to put a fuse in and the relay back in at the fuse box...as long as these connections weren't wires I deleted...Then I need to figure out which pin/wire on the ECM needs to be tricked to thinking it is still there....
Oh Yeah, More fun!
Thanks,
Shoebox for the info
Greg
Thread Starter
Registered User
Joined: Jul 2007
Posts: 198
From: Norton, MA
Update, almost there any ideas on the codes?
Well I am going to put my guess on 2 bad injectors for now, I'll keep everybody posted.
Shoebox just answered my Code 29 question as me needing to put a fuse in and the relay back in at the fuse box...as long as these connections weren't wires I deleted...Then I need to figure out which pin/wire on the ECM needs to be tricked to thinking it is still there....
Oh Yeah, More fun!
Thanks,
Shoebox for the info
Greg
Shoebox just answered my Code 29 question as me needing to put a fuse in and the relay back in at the fuse box...as long as these connections weren't wires I deleted...Then I need to figure out which pin/wire on the ECM needs to be tricked to thinking it is still there....
Oh Yeah, More fun!
Thanks,
Shoebox for the info
Greg
Amazing that the injectors just clog up like that from just sitting for a year, they were running just a year ago.
Now I still have the two codes to clear:
#43 Electronic Spark Control
#29 EAS Electrical Failure
I tested the new knock sensor and it is reading fine, right at 3300 ohms
I do not have the 5 Volts at the connector.
I am going to have to get the ECU back out from behind the dash and check for the 5 Volts at Pin D22 dark blue wire on the "D" blue connector, if present there I will have to run a new wire as there must be a break in it somewhere. If not present I am not sure what to do, possibly a bad PCM? or should I suspect the Knock module in the PCM? should I just get an LT4 module?
http://shbox.com/1/1995_pcm2.jpg
According to Freescan I am registering knocks and it does occasionally retard the timing so is the sensor working? I don't get it....
test proceedure is here:
http://shbox.com/1/4th_gen_tech2.html#knock_sensor
On the air pump code I am not sure what to do to clear this code, I do not have the relay or fuse wiring left for this circuit. I guess the PCM senses the coil resistance of the relay?? Other forums say just put the relay and fuse back in and the code will clear but I eliminated all that wiring so can I just measure the relay coil impedance and just put a resistor on that pin?
See pin A14 in the diagram
http://shbox.com/1/1995_pcm4.jpg
SO I have the SES light on and the fan runs constantly but according to Freescan it does go from open loop to closed loop the temp is usually around 178 and I have a 160 thermostat
Will my fan operate normally when I get rid of the SES light trouble codes?
I am almost there I am so close to driving this on the street!
I think my Mallory 110FI fuel pump may be acting up, I already had it sent back to Mallory once already, it is LOUD and sometimes sounds funny and fluctuates pressure.
Is everybody else running one of the Walbro pumps?
I need an external unit not an in-tank unit
My Mallory is an -8AN but all my lines are -6AN what size is the Walbro units and what model should I order?
Thanks,
Greg
Administrator
Joined: Nov 1998
Posts: 71,109
From: Hell was full so they sent me to NJ
DTC 43 is failure of the knock sensor circuit. When the circuit fails, and you get DTC 43, the PCM retards the timing almost all the time, calculating the retard from other sensor data. Knock "counts" have nothing to do with the knock sensor and whether its working or not. You already figured out how to work your way back along the wiring from the sensor to the PCM. You have to continue in that direction. What did you use as a "ground" when you measured the voltage on the single conductor wire that runs to the knock sensor?
Are you aware that a mail order tuner could eliminate the DTC 29 code? It would appear that you just need to run the #436 circuit (brown wire from A14) through a relay coil, and then to a fuse and a 12V power source. Measuring the resistance of the coil would give you an equivalent resistor, but the resistor would have to be substantial watt rating, to absorb the power that its going to consume when the resulting current flows through it.
Are you aware that a mail order tuner could eliminate the DTC 29 code? It would appear that you just need to run the #436 circuit (brown wire from A14) through a relay coil, and then to a fuse and a 12V power source. Measuring the resistance of the coil would give you an equivalent resistor, but the resistor would have to be substantial watt rating, to absorb the power that its going to consume when the resulting current flows through it.
Registered User
Joined: Aug 2007
Posts: 305
Is the computer from the caddy or from the trans am? What wire harness are you using?
When I did a swap to a 66 el camino I used a camero harness and a caprice computer. Had everything working but the motor was running retarded with dtc43. After spending hours on the phone with the company that built my harness and getting no where I decided to add a knock sensor because the caprice came with one on each side of the block. Problem went away as the computer was looking for the restance from 2 knock sensors, not one. Hope this helps.
When I did a swap to a 66 el camino I used a camero harness and a caprice computer. Had everything working but the motor was running retarded with dtc43. After spending hours on the phone with the company that built my harness and getting no where I decided to add a knock sensor because the caprice came with one on each side of the block. Problem went away as the computer was looking for the restance from 2 knock sensors, not one. Hope this helps.
Thread Starter
Registered User
Joined: Jul 2007
Posts: 198
From: Norton, MA
Is the computer from the caddy or from the trans am? What wire harness are you using?
When I did a swap to a 66 el camino I used a camero harness and a caprice computer. Had everything working but the motor was running retarded with dtc43. After spending hours on the phone with the company that built my harness and getting no where I decided to add a knock sensor because the caprice came with one on each side of the block. Problem went away as the computer was looking for the restance from 2 knock sensors, not one. Hope this helps.
When I did a swap to a 66 el camino I used a camero harness and a caprice computer. Had everything working but the motor was running retarded with dtc43. After spending hours on the phone with the company that built my harness and getting no where I decided to add a knock sensor because the caprice came with one on each side of the block. Problem went away as the computer was looking for the restance from 2 knock sensors, not one. Hope this helps.
I am going to try and see what I find today.
Thanks,
Greg
Thread Starter
Registered User
Joined: Jul 2007
Posts: 198
From: Norton, MA
DTC 43 is failure of the knock sensor circuit. When the circuit fails, and you get DTC 43, the PCM retards the timing almost all the time, calculating the retard from other sensor data. Knock "counts" have nothing to do with the knock sensor and whether its working or not. You already figured out how to work your way back along the wiring from the sensor to the PCM. You have to continue in that direction. What did you use as a "ground" when you measured the voltage on the single conductor wire that runs to the knock sensor?
Are you aware that a mail order tuner could eliminate the DTC 29 code? It would appear that you just need to run the #436 circuit (brown wire from A14) through a relay coil, and then to a fuse and a 12V power source. Measuring the resistance of the coil would give you an equivalent resistor, but the resistor would have to be substantial watt rating, to absorb the power that its going to consume when the resulting current flows through it.
Are you aware that a mail order tuner could eliminate the DTC 29 code? It would appear that you just need to run the #436 circuit (brown wire from A14) through a relay coil, and then to a fuse and a 12V power source. Measuring the resistance of the coil would give you an equivalent resistor, but the resistor would have to be substantial watt rating, to absorb the power that its going to consume when the resulting current flows through it.
So I'll have to check to see if I can eliminate DTC 29 with TunerCAT, having a problem connecting right now though....ARGH!
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