fasteddy
Web Wheeler
Reged: 01/30/01
Posts: 12707
Loc: Flat Creek, GA
|
|
Crank signal is starter running signal, I guess, not distributor originated, for fuel pump run in start even if no spark signal.
I looked up the o2 sensor voltage directions, and more voltage is richer, and less is leaner. Voltage going higher is correct for accel enrichment when you crack the throttle to speed up the engine, and tps voltage going higher is a sign that something is happening there, and probably in the right direction.
I would now manually set the dizzy timing to the factory spec (I think you said 5+/-2*) with the timing light, because that spec from the MUT is very high for idle advance, even at the somewhat elevated idle rpms. Isn't there an adjustable bypass for manual setting of base idle speed? I'd get the idle rpm's right, then set the timing. With that much advance, you could get peak (or high at least) cylinder pressures BEFORE tdc, so the piston is fighting combustion pressure before it gets to the top of the stroke and starts to make power, so the engine is fighting itself, especially if the ecu adds accel advance in response to falling MAP pressure readings and opening throttle via the tps, and increasing air flow from the afm.
I'm not looking at the diagnostic readings from the manual, but the rest at least looks ok to me, the only problems I see right off the bat are idle speed and timing connector grounded advance on the spark.
--------------------
"If you can't be a good influence, don't worry, you can still be a horrid example."
|
Big Blue
Roll Me Over
Reged: 12/06/00
Posts: 2967
Loc: Brier,Wa,USA
|
|
Quote:
'91 Montero LS (timing adjustment connector grounded)
ADV IGNITION BTDC 21/22 degrees
ISC STEP MOTOR 7 step
Inhibitor SW N,P
INJECTOR 4.3/4.6mS (8.7mS when trying to accelerate) 
Power Steering SW OFF
A/C SW OFF
IDLE SW OFF
CLT TEMP SNSR 187-189 degrees F.
CRANK ANGLE SNSR 1125-1152 RPM
BATT VOLTAGE 13.9V
CRANK SIGNAL OFF
AIR TEMP SNSR 81 degrees F.
TPS 820mV (1425mV when trying to accelerate)
OXYGEN SNSR 39/58mV (117mV when trying to accelerate)  
AFS 106Hz (156Hz when trying to accelerate)
A/C RELAY OFF
BARO PRS SNSR 738mmHg
Powell
we have a winner!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Injection Ms seems slightly high for idle.........BUT idle is slightly high also (normal Ms should be ~2.3Ms)
LOOK AT THE O2 SENSOR!!!!!!!!!!!!!!!!!!!!!
It should be fluctating between .2V (200mv) and .8V (800mv)
ANd when accelerating it should go to .8V (800mv) and stay there. When NOT operating it should have an output of .48v (480mv)
Why is this puppy so darn lean???????????????
Disconnect the o2 sensor and it should go to .48v
Now the question?.... why is the injection Ms high, but the o2 so low??? Is the o2 driving the ecu to richen up the mix, or is there something else (Vacuum leak) ???????
Also Idle switch....I would think that the idle switch should be closed at idle.. but easy to check on one of your other rigs.
I love this stuff  .......Customers lie like rugs..........The motor can't lie to you. 
Kary
--------------------
1987 Mitsubishi Pajero "Modified"
The other original Mitsu brother
Northwest Trailmaster
|
fasteddy
Web Wheeler
Reged: 01/30/01
Posts: 12707
Loc: Flat Creek, GA
|
|
See, all it takes is an encyclopedic knowledge of what the readings ought to be, and to sherlock the right actual malfunction from the data available, and the data available is SO much better than it used to be, even if it's just error codes and you have to pull your own millivolt/amp/ohm reading. The MUT is nice! See why I want programmable efi? It gives you the data on all these sensors, and you can diagnose with ease (and a wad of logic).
Kary, what about the highly advanced base timing, and is the efi sequential?
--------------------
"If you can't be a good influence, don't worry, you can still be a horrid example."
|
Big Blue
Roll Me Over
Reged: 12/06/00
Posts: 2967
Loc: Brier,Wa,USA
|
|
Discount the advanced timing.
1. Powell's truck read close to the same.
2. This could be taken using a magnetic reading at the factory, so it my not be the actual reading but a product of base and actual and offset.
This appears to be bank to bank or batch injection as there is only 1 injection reading but I'm not sure of the software used with this unit.
Kary
--------------------
1987 Mitsubishi Pajero "Modified"
The other original Mitsu brother
Northwest Trailmaster
|
pmontero
Roll Me Over
Reged: 07/12/01
Posts: 3167
Loc: Peachtree City, GA USA
|
|
Thanks Kary,
Here is some more information from me and the customer that might help. When I first started working on the truck, the owner had tried to remove the O2 sensor to replace it and stripped it out of the hole in the exhaust pipe. I ran the correct metric tap in the hole to clear out the stripped sensor threads and installed a brand new Bosch OE O2 sensor that came with the correct plug so it just snapped to the connector on the Mitsu wiring harness. Also, the truck was having the acceleration problem before we did the heads and the O2 sensor.
I'm not discounting any analysis here. Just sharing more of the story. It could still be the O2 sensor but I'm leaning toward Kary's vacuum comments.
I need Vacuum 101 please. I checked the brake booster vaccuum hose and it appears ok. I checked the vacuum line that runs from the TB to the fuel pressure regulator and it's ok. I checked the vacuum line that runs from the top of the plenum to the charcoal canister and it appears to be ok. Could someone run down a list of all the vacuum related connections I should check? I have a MityVac with gauge so I can check all the connections. I just need a complete list.
Thanks for the help,
Powell
--------------------
'87 Montero Diesel
'98 Porsche Boxster Electric
and more...
Greasology
NotPetroleum
|
pmontero
Roll Me Over
Reged: 07/12/01
Posts: 3167
Loc: Peachtree City, GA USA
|
|
Quote:
Powell,
Where does the distributor rotor point with the engine at TDC on the compression stroke?
Frank
Frank,
I got so excited about the "Crank Signal OFF" code that I didn't pull the dizzy cap off to check. I'll do this next time and report back.
Thanks and sorry for the slow response,
Powell
--------------------
'87 Montero Diesel
'98 Porsche Boxster Electric
and more...
Greasology
NotPetroleum
|
FrankR
Web Wheeler
Reged: 02/01/04
Posts: 10225
Loc: Columbia, SC
|
|
OK, Powell - don't forget to check the timing connector shunt to make sure it's actually grounded.
Frank
--------------------
'89 G-Raider Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 155k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, 165A alt., Lifeline AGM, Rust-Oleum
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
