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Topic: Proper injectors for stock Speed Density 5.0 (Read 6198 times) previous topic - next topic

Re: Proper injectors for stock Speed Density 5.0

Reply #15
yes, it was removed.  New gaskets and o rings were used in the intake/injector re-installation.  I'll check vacuum...
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 3.8 V6 - Rescue
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 5.0 V8 - Survivor

Re: Proper injectors for stock Speed Density 5.0

Reply #16
Vacuum is at 19-20 at idle
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 3.8 V6 - Rescue
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 5.0 V8 - Survivor

Re: Proper injectors for stock Speed Density 5.0

Reply #17
Have you checked for codes?

Re: Proper injectors for stock Speed Density 5.0

Reply #18
checked codes, none stored, CEL isn't on.  Noticed that the exhaust odor is more pungent than usual, and quite a lot of water/carbon came out of the tailpipes yesterday when i had it running/revved it up in the driveway.  Wondering if maybe the converter is getting clogged up, and my removal of the smog system didnt help things
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 3.8 V6 - Rescue
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 5.0 V8 - Survivor

Re: Proper injectors for stock Speed Density 5.0

Reply #19
You should get a code 11 if there are no fault codes.
If you got no codes of any kind, it could mean the EEC software is not running.
Put the key in run without cranking and the fuel pump should run for a couple of seconds and shut off.
If it runs continuously, that's another indication the software is not running.

Re: Proper injectors for stock Speed Density 5.0

Reply #20
No codes can also be a blown signal return circuit in the EEC.
The one wire (pigtail) at the test connector is the signal return.
There are 5 sensors that will not be working if the signal return is blown:
MAP, TPS, ACT, ECT & EGR position.

With the key on, check for 5v between the O/W wire (ref v) and the BK/W wire (sig rtn) at the TPS.
People have fixed this problem by opening up the EEC and tracing pin 46 circuit to find the blown spot and soldering a wire across the open circuit.

Re: Proper injectors for stock Speed Density 5.0

Reply #21
Sorry for the delay, I just checked my codes, as the light came on briefly the other night while driving.  Unlike OBD2 codes, it seems that OBD1 codes are stored after the key is shut off, so the CEL does not come back on again?  I ran the codes, both with key on engine off, and key on engine running, and got several stored codes;

11
91 - No oxygen sensor switching detected
41 - Oxygen sensor circuit indicates system always lean
21 - Engine coolant temperature (ECT) out of self-test range
42 - Oxygen sensor circuit indicates system always rich
92 - Shift solenoid circuit failure
18 - Ignition diagnostic monitor (IDM) circuit failure

code 92 i can attribute to the time i accidentally knocked off my kickdown cable a few weeks back.  Also, I can say the car is running SUPER rich; the exhaust smells like shiznit, and it's been getting worse, it's embarrassing now.  I'm pretty sure the bad mixture is causing the idle surge, rather than the IAC or TPS, I just dont know whats attributing the bad mixture.  Could it be bad O2 sensors, since 3 codes have to do with oxygen sensing?

A nagging guy at my shop says my smog pump delete is causing all this problem, but I really don't understand how it could be, since I left no vacuum leaks, and did not remove any electrical connectors or sensors.
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 3.8 V6 - Rescue
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 5.0 V8 - Survivor

Re: Proper injectors for stock Speed Density 5.0

Reply #22
I would check the ECT first.
It will have a 2 wire connecter. BK/W and LG/Y wires.
If the one of the wires is broke, this will indicate to the EEC that the engine is super cold.

The ECT resistance range needed to pass the KOEO test  : 50°F = 58.75 K ohms,  220° F = 1.84 K ohms.

Re: Proper injectors for stock Speed Density 5.0

Reply #23
I was too quick to jump on the ECT as your cause of running rich.
First we have to sort out when you got the codes.
The codes can have different meanings depending on when you got them.
For example, if you only got the 21 code from KOER, it means you didn't warm up the engine before running the test.

KOEO (Key On Engine Off)
Memory
KOER (Key On Engine Running)

KOEO runs self tests then presents on-demand codes (O). After a single separator pulse. presents memory codes(M).
KOER presents an engine code, 4 for 8 cylinder. Then runs tests and presents running codes(R).

Re: Proper injectors for stock Speed Density 5.0

Reply #24
Code 18 R SPOUT c°ircuit open during self test (Check the jumper plug)
Code 18 M Loss of signal from coil negative, Ignition diagnostic monitor. Or spout grounded.

code 21 O&R ECT out of test range.
   To pass test, coolant temp must be:
   KOEO- 50° F to 240° F
   KOER- 180° F to 240° F
Code 41 R  Right O2 sensor shows lean
Code 41 M  Right O2 sensor not switching (stays lean for 15 seconds or more)
Code 42  R  Right O2 sensor shows rich
Code 42  M  Right O2 sensor not switching (stays rich for 15 seconds or more)
Code 91  R   Left O2 sensor shows lean
Code 91  M  Left O2 sensor not switching (Stays lean for 15 seconds or more)
Code 92  R   Left O2 sensor shows rich
Code 92  M  Left O2 sensor not switching (Stays rich for 15 seconds or longer)

Re: Proper injectors for stock Speed Density 5.0

Reply #25
ECT out of range can happen if the test is run on a cold motor. If that's the case ignore it.

41, 42, 91, 92 narrows it down. Check the oxygen sensor harness. Make sure that the harness is intact and plugged in on the correct sides. If the right side oxygen senor is plugged into the left side oxygen senor connector (for example) then there will be all sorts of screwy problems.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.


Re: Proper injectors for stock Speed Density 5.0

Reply #27

OP said car has 20" of vacuum at idle. It could be a vacuum leak but that reading is on point for a stock engine.

But I wouldn't be surprised by a vacuum leak somewhere either.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: Proper injectors for stock Speed Density 5.0

Reply #28
I want OP to spray brake cleaner around the intake side of those injectors at idle, as well as the general space under the plenum. Maybe try a known good MAP sensor.  Is OP measuring vac at the booster, the PCV or the MAP?  That upper intake has been off and the injectors out, 9 of 10 times, it's a vacuum leak someplace that's getting overlooked in the previous work area.  Is MAP (as the primary load sensor) connected to the upper, and is it connected in the right place?  Were the injector o-rings lubed before installation into the manifold?  A torn injector o-ring that was installed dry will vacuum leak and you'll never hear it.

Re: Proper injectors for stock Speed Density 5.0

Reply #29
measured vacuum at the vacuum distribution block.  the injector o rings were lubed, yes.  if the vacuum leak is small enough that I am still getting a 20lb reading, could that really be attributing to such harsh idle consequences, and overfueling?  I'm leaning toward o2 sensor/failure as Thunderjet suggested...
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 3.8 V6 - Rescue
1988 Cougar LS - Cinnabar/Rose Quartz Metallic two tone - 5.0 V8 - Survivor