ID this connector, and help with cold start stumble needed

[TJs98GT]

during my explorer gt40 manifold swap i found this loose/broken connector. Located right next to my ect sensor. What do you think this is supposed to attach to? I'm thinking this could be the cause of my problems maybe?

View attachment 154741

I bought this 88 notchback back in november and have battling this issue since the beginning. It did have 3 stuck injectors and a stuck FPR which I already replaced and the car drives a lot better and feels like it has a lot more power but I still cant get past these issues.

I have already done the following:
-replaced all injectors with new style 19# injectors
-replaced FPR
-replaced IAC
-replaced and adjusted TPS
-replaced all top end gaskets with new fel pro pieces and installed explorer GT40 intake manifold
-replaced ECT sensor
-replaced ACT sensor
-new platinum spark plugs
-previous owner installed FRPP spark plug wires
-inspected cap and rotor - look fine
-replaced numerous old vacuum lines
-replaced fuel pump(had 91 5.0 fuel pump laying around) and in take fuel hoses

Not yet done:
-replace MAP sensor
-replace distributor

Still upon cold start up this morning it will fire right up, but the second you touch the gas it either cuts out and dies completely or backfires out of the intake. Once warm it will not stall when giving it gas but does occasionally backfire. When driving the car revs smooth and makes good power but almost can feel a slight miss through the power band. Also, it seems like at idle it doesnt idle quite as smooth as it should.

Motor does not smoke at all and was told the motor has about 70k miles on it.

Any ideas where to go next? One of my coworkers is going to look at it when he has time, but who knows when that will be since our shop has been really busy so personal projects often get put to the side forever. I really want to get this car on the road ASAP though.

 

[Rick 91GT]

That is where the harness for the smog pump/equipmentuse to go.

 

[TJs98GT]

ok, which is odd since its all still there. That shouldnt lead to my problems though.

 

[Boydster]

That goes to the carbon canister purge solenoid. Should be located along the side of the frame rail below your stock airbox.

 

[TJs98GT]

That goes to the carbon canister purge solenoid. Should be located along the side of the frame rail below your stock airbox.

Which I did have a code for last time it was running. Makes sense now. Id like to delete that whole set up I think. This not being hooked up shouldnt cause any type of running problems right?

 

[Rick 91GT]

Doh..i was thinking of right part and type pump...been a long day. Correct is goes to the purge ...I may have a harness at the shop, I keep all of that stuff. Ill look later tonight when I go back.

 

[jrichker]

Backfiring out the intake is either a valve stuck open or a lean mixture or spark plug wire(s) connected to the wrong cylinder(s). Check compression on all cylinders and then look for vacuum hoses loose, cracked, or misconnected. Check the line for the vapor recirculation system – it is easy to knock loose and not see it when you connect the air pump plumbing. If the vacuum line for the EGR valve and the air pump are cross connected, some very strange things can happen. Check the mass air flow electrical connection and see that it is tight, the same goes for the fuel injection wiring harness connectors up on top of the manifold near the firewall.

Sticking valves: If a intake valve is bent, has a bad spring or is misadjusted, the engine will sometimes backfire through the intake. Use a vacuum gauge connected to any convenient spot on the intake manifold. Run the engine at 1000 RPM & look for 18-21 inches of vacuum with a steady needle. A problem intake valve will make the vacuum gauge needle sweep 5-10 inches.

Lean fuel mixture breaks out into several sub categories:
A.). Vacuum leaks
B.) Air entering the intake without passing through the MAF on Mass Air cars (89-95 models).
C.) Failure of the MAF, BAP/MAP (Baro or Manifold Air Pressure, same sensor, different name), ACT (air charge temp), or ECT (engine coolant temp). These should set a code in the computer.
D.) O2 sensor problems: one or both O2 sensors with low output or bad O2 sensor heater ground. This should set codes 41/91. The O2 sensor heater ground is an Orange wire in the engine mounted fuel injector harness. Ground it to the back of the head or intake manifold.
E.) Leaking exhaust gases from EGR valve at WOT or EGR opening when it should not be open.
F.) Poor fuel delivery due to bad fuel pump, clogged filter or bad fuel pump wiring. Look for low pressure or fluctuating pressure. Standard injector pressure is 39 PSI at idle, with the vacuum line disconnected from the regulator and capped.
G.) Clogged fuel injectors.- see the cylinder balance test below
H.) Fuel injector wiring problems causing injector not to deliver rated flow (dirty or stuck shut injectors).
I.) Computer problems: (computer problems are not common like sensor problems)
J.). ROM has bad data in fuel or timing table. This should also set a code in the computer.
K.) Failure of one or more of the computer's driver transistors for the fuel injectors. No code set on this one. Use a noid test light to test the injector wiring & injector drivers,
L.) MAF calibration off or mismatched to injectors.
M.) ACT or ECT bad. Sometimes the sensors will be off calibration, but not bad enough to set a code. If they falsely read too high a temp, the engine will back off fuel delivery.

Cylinder balance test:
See the procedure below to dump the codes and place the computer into diagnostic mode.

Warm the car's engine up to normal operating temperature. Use a jumper wire or paper clip to put the computer into test mode. Start the engine and let it go through the normal diagnostic tests, then quickly press the throttle to the floor. The engine RPM should exceed 2500 RPM's for a brief second. The engine RPM's will increase to about 1450-1600 RPM and hold steady. The engine will shut off power to each injector, one at a time. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures. Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure

Dump the codes: Codes may be present even if the Check Engine Light (CEL) isn't on.

Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.

Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.

If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and driveablity problems

Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor, and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[Rick 91GT]

Do u have the stock oil fill cap on the valve cover or a breather?

 

[TJs98GT]

I will hook up one of our Snap On Verus or Solus scanners and check it for codes to see what comes up again and go from there. Last time I only noticed a code for the canister purge solenoid if I remember correctly, but that was 2 months ago. Ill scan it again with all the new parts and see if anything comes up and also check for some of the items listed above.

And yes, original oil fill and breather cap(passenger side goes up to throttle body)

 

[Boydster]

Which I did have a code for last time it was running. Makes sense now. Id like to delete that whole set up I think. This not being hooked up shouldnt cause any type of running problems right?

Deleting the carbon canister setup isn't difficult. There's a vent line from the fuel tank that needs to stay open. Tossing everything else (canister, purge valve, vacuum line to the intake manifold) is easy, make sure to plug the vac tree where the line is removed under the intake manifold. But... your engine compartment will smell like fuel and especially after filling up, if you have a garage, it will always stink like raw fuel. It costs zero power to leave it installed and keeps your car from stinking.

If the purge valve is open with the connector removed, it could cause a vac leak and that could cause running problems.

Best quick way to isolate that is to just remove the vac line from the intake and plug it. That doesn't fix anything, but does help isolate your running problem.

 

[TJs98GT]

KOEO Test = 2 codes, 84 one for the canister purge solenoid that isnt connected(but also said 84-o for a lean condition) and one for the ACT sensor I forgot to plug in, but realized right after I started it.

KOER test = 44 thermactor system not working, and code 94 CCC/SS4 Circuit fault/thermactor air inoperative.

 

[OonDeanisS]

try unplugging your MAF and see if it runs better... if it does, you may have a problem there, or if it gets worse, in another sensor.i have the same issue, and mine runs better without the MAF plugged in... im just saving money for a new one.