86GT - Crank, Start, NO GO! - Need Advice Please

[tillryan86]

Trying to determine how to approach this situation:

1986 Mustang GT - car will start and idle but will not move -- I rev up to 3500 RPM and the car begins to crawl away (this applies to all gears in T5 Standard Transmission)

Recent History:
I recently pulled the car out from storage where it sat for about 1 year. Just prior to storage I installed 65mm Throttle Body. Shortly after pulling from storage the car would die on idle, buck when accelerating, and a noticeable hesitation when accelerating. I was having to reset the TPS sensor over and again as it would not stay at consistent voltage (I would set .88v -.96v and it would end up back over 1.0v). I have been certain for awhile it needed a new IAC as well.

-Shortly after removal from storage the car had voltage issue --- (3 years ago installed SVE 130 AMP 3G alternator - failed about 2 years ago and was replaced) and the voltage regulator was replaced 2 months ago for failing by fluctuating voltage - getting to low (13 volts) and not staying at 14.5v

I have replaced PCM relay and Fuel Pump Relay.
I have tested fuel pressure which was at 30-33 PSI with fuel regulator and 40 PSI + with regulator capped.
I have tested for consistent spark
Tune up done just prior to storage - (Plugs, Wires, Screamin Demon Coil, Cap/rotor)
I have run the codes and I receive the secondary Air Injection System Inoperative codes (94/44) but I expected to

Side Note: Heard Rattling at Crank Pulley - investigated and found 2 out of 4 hex bolts were a little loose (aluminum under drive crank puley)

Prior History:
Smog Pumped Removed - Still have EGR - Plugged behind Cylinder heads
Long Tubes, off-road h-pipe
CAI
bigger battery relocated to hatch
upgraded started
dual electric fan SVE Aluminum Radiator
Aluminum Under Drive Pulleys (Crank and Water Pump)
upgraded 255 lph Walbro Fuel Pump
130 amp SVE 3G Alternator upgrade
NO major engine mods


IDEAS:
After replacing voltage regulator I still planned on replacing IAC. I have been trying to determine if this vacuum related or electronic and the fuel injectors are not firing or something or is it the inside the engine...

I am thinking of replacing TPS, IAC and maybe ECT (which is less than 2 years old) and ACT and maybe O2 - I am confused because this is a major power loss - the car will not move until WOT and then barely accelerates.

Also, thinking about EGR delete vs replace EGR position sensor and EGR Valve
I have not yet found noticeable vacuum leaks but it is all 30 years old


Any advice and input on this would be greatly appreciated. Im not sure the right direction to move forward

thank you

[tillryan86]

I replaced the fuel pump relay after 2 or 3 occassions when it demonstrated a crank no start situation - after replacing relay I realized I needed to press the gas pedal down to the floor

[99GTMichael]

EGR stuck wide open can flood the engine at low RPM with non-violate mix. If the engine clears up with wide open throttle, this could be a possibility.

[emerygt350]

Is your clutch shot or not disengaging?? Hard to understand what you mean by the car won't move in gear or only starts to crawl at 3500.

[tillryan86]

EGR advice is a good lead, thank you

not sure what you mean by "ducth shot"

So I wanted to give idea of the issues I have been having since removing car from storage, being IAC, voltage regular, and TPS sensor, because I dont know if they're connected or separate

But basically, the car starts up, it will hold idle, half of the time, but when I press down the pedal to accelerate, the car doesnt move, I press down more to 2500 RPM to 3500 RPM to 4000 RPM and the car gradually begins to roll forward -- this is same sort of response in 1st, 2nd, 3rd, reverse

[tillryan86]

99GTMichael - would EGR delete help this situation or hurt this situation?
thanks

[swearint]

As emerygt350 suggested, it sounds to me like a bad clutch. Either it is slipping or stuck in a "mostly" disengaged position.

[99GTMichael]

I'm having a tough time wrapping my head around this issue. Can you freely rev the engine in neutral and it revs cleanly?

You could also crack open the bleeders on the brakes to see if any of them are holding obscene pressure.

I've had clutches rust-weld themselves to flywheels after cars sit a long time. This manifests itself as your are starting the car in gear essentially, doesn't sound like your issue, though. Perhaps clutch cable has been horribly burned by your longtube headers? How does the clutch pedal feel?

As far as EGR goes... I'm not super familiar with the Foxbody setup. I assume is vacuum actuated somehow. Basically, what I would do is remove the EGR valve to see if it is physically stuck open, say with a chunk of carbon. According to quick service information I just pulled up, it looks vacuum operated with a thermostatic switch to send vacuum to it. I think your hood or core support should have an emissions system decal on it diagramming the system. You could try to open and close the EGR valve with a vacuum pump to see how it reacts or if it will un-stick itself (if that is the issue.)

In fact, here's the EGR testing procedure from All-Data. This should be a quick check, so even if I have led you done the wrong path, it won't be super involved.

1. Make certain that all vacuum hoses are correctly routed and securely attached. Replace cracked crimped or broken hoses.
2. Make certain there is no vacuum to the EGR valve at idle with the engine at normal operating temperature.
3. Install a tachometer.
4. Disconnect the Idle Air Bypass Valve (9F715) electrical connector (EFI engines only).
5. Remove the vacuum supply hose from the EGR valve nipple. Plug the hose.
6. Start engine, idle with transmission in NEUTRAL, and observe the engine idle speed. If necessary, adjust idle speed to the emission decal specification.
7. Slowly apply 5-10 inches of mercury vacuum to the EGR valve vacuum nipple using a hand vacuum pump.
6. When vacuum is applied to the EGR valve and any of the following occur, replace the valve:
^ Engine does not stall.
^ Idle speed does not drop more than 100 rpm.
^ Idle speed does not return to normal (±25 rpm) after the vacuum is removed.
9. Reconnect the idle air bypass valve electrical connector.
10. Unplug and reconnect the EGR vacuum supply hose.
11. The EGR system is OK.


EGR is kinda up to your preference when it comes to deleting. I've never seen a race engine with EGR, but every street engine has EGR. It's an emissions device as well as a cooling effect on the cylinders. I don't have EGR on the '83 Lean-To Rescue car, but it doesn't have any emissions devices anymore. Conversely, I wouldn't dream of deleting the EGR on my unmodified '99 4.6L. I'm trying to recall what I was taught in auto tech school, but that's been a few years.

Edit-I am inclined to say a CLUTCH issue the more I think about it. Could have a combination of a couple things going on, given that you've have runability issues as well.

3rd edit- Grab your clutch pedal, and pull UP on it. As in, toward the steering wheel. The factory system uses an automatic clutch adjustment system. Also from service information-

A self adjusting type clutch mechanism is used. The adjust mechanism consists of a spring loaded ratchet quadrant attached to the clutch cable. To accomplish this adjustment, grasp clutch pedal and pull upward, then slowly depress clutch pedal. If a click is heard during the procedure, an adjustment was necessary and has been accomplished. This procedure should be performed at least every 5000 miles.

[toddf]

have you tried putting it on jack stands and rolling through the gears with less resistance?
That would let you know if it was the clutch not holding.

[tillryan86]

I installed new exedy mach 400 stage 1 clutch, came with steel flywheel and 50 oz weight
Installed new pilot bearing, rear main seal and throwout bearing and adjustable clutch cable
Also installed new ACT sensor and Temp sending sensor, and IAC

tried to test today and it fires up but immediately dies

any suggestions greatly appreciated

[Tigger]

I would start with checking for codes.

Do you find out your clutch was bad?

[tillryan86]

I honestly could not see anything that told me it was clearly damaged other than wear on flywheel and clutch disc

the transmission slid right out, throw out bearing and clutch fork all fell apart right away as if maybe fell out of alignment but i dont know...

all i know at this time is that TPS sensor is reading at .03 volts

[Foxy 83.5]

Fires but dies could be a vacuum leak.

[KevinK]

Frozen brakes? Check all 4 wheels spin freely.

[Haystack]

Tps at .03 volts is why it doesnt want to run. Forget about thr made up 1.0 volts. Anywhere from about .6-1.20 volts is withing range and wont effect day to day operation.

.03 volts leads me to believe you have a computer power/ground problem or that the sensor is totally bad.

The computer uses 5v. So you should have a voltage refference of 5v, then around 1v at idle and then a ground on the 3 prong connector.

If you arent getting 5v then I would start checking for power at the computer.

[tillryan86]

.03 volts at TPS sensor and connector

Check fusible links from started solenoid for computer power?
Could computer be bad? Circuit board itself not producing power?

I have a few relays to try but does not seem to change outcome

Thanks

[mudgepondexpress]

How is the tranny about? Is the throw out bearing hanging up not letting the clutch fully engaged? Stock aluminum snout (bearing retainers), are noted for heavy scoring.

[tillryan86]

There was already a steel bearing retainer
Really had to push transmission to get into pilot bearing

The clutch fork feels loose, good gap between throw out bearing and pressure plate until I tighten the clutch cable

I can shift into all gears on transmission without depressing clutch, I dont remember if this was normal without car running

[tillryan86]

There was already a steel bearing retainer
Really had to push transmission to get into pilot bearing

The clutch fork feels loose, good gap between throw out bearing and pressure plate until I tighten the clutch cable

I can shift into all gears on transmission without depressing clutch, I dont remember if this was normal without car running

[Haystack]

You need to see if you have 5v on the reference wire of the tps. This will tell you if them computer has power. Deal with the trans stuff once its running right.

[tillryan86]

Checked the orange and white wire at the salt and pepper shakers
Being pin 2 vref for sensors and I got less than .3 volts

Followed this orange white wire to the computer which also read less than .3 volts

[Haystack]

You have no power to the computer then. Check the eec relay.

Goto sbftech efi no start and check from there.

[emerygt350]

How could it run at all with no power to the computer. OP needs to describe the problem, as it is now, clearly.

[tillryan86]

1986 Mustang GT 502 5.0 V8

Pulled the car out of storage 3 months ago after sitting for a year.

I had problems with TPS voltage not staying consistent, I was constantly re-adjusting it due to Idle Problems and Drivabilty Issues and around this time I had to replace the Voltage Regulator on 3G Alternator.

Last month, the car would start and idle but almost now power was going to rear wheels. I would rev up to 4000 rpm in order to move stand still.

Last Week I replaced:
Clutch
Flywheel
Pilot Bearing
Throw Out Bearing
Rear main seal
IAC
Adjustable Clutch Cable
ACT sensor

When all said and done, I go to start to the car and it does fire up but immediately dies

I checked TPS sensor, EGR Sensor, 10 Pin Connection (white salt Shaker) on #2 pin for Vref -- and all have less then 1 volt
I went to computer and checked the orange/white wire (pin 26) which supposedly supplies Vref and it also is less than 1 volt

The Fuel Pump Primes - Have battery voltage at Pink/Black wire from Fuel Pump Relay
I am getting power from Starter Relay to ECC Relay - Black/Red wire at ECC Relay has battery voltage and fusible link at starter relay is good
I have checked for spark with spark tester at Ignition Coil and Spark Plug #1 which both spark in the quick time before car dies
I hooked up a pressure gauge to schraeder valve on fuel rail which went up to 30 psi before dying
I tested Fuel Injector by placing volt meter lead on battery ground and other lead on positive terminal of connector and had less than 1 volt
computer ground is good, engine block grounds appear to be good

At this time appears that the correct voltage is not reaching TPS, EGR, ACT, Fuel Injectors
Is computer bad? Internal or external?

I am not certain where to look next for this lack of voltage either from computer to 10 pin connector/fuel injector harness or to computer to supply the voltage

thanks

Also, the computer will not enter into self-diagnostic at this time (using test light and paper clip at self test port)
and guage cluster is not responding - no reading for: oil pressure, engine temp, gas gauge

[Haystack]

That's why I brought up the sbftech efi no start. It will tell you where you need to look for power.

My guess is that you have a bad connection to track down somewhere. My buddy had a car that just died one day. Checking the tps I had 12v's on my digital meter. Eventually we found continuity everywhere and ruled out the computer. Following the sbftech write up step by step, we eventually tracked it down to the computer ground right by the battery. When I touched the connector to try to unplug it, the wire fell out of the connector.

Buttsplice to get us home and never had another problem out of it.

Where you have some, but not enough voltage, I think you will find an issue between the eec relay and the ignition switch if I had to wager a guess.