Won't run, period. help?

[BandY]

Obviously, I've been here a while. Well, I'm here again at square one. I CANNOT get this thing to run right. Now, it runs so terribly that I can't even convince it to go down the road.

This is what has happened, to date...

The fuel pump was replaced, and then the whole gas tank replaced, because of realizing how much rusted crap was in the old one, from the inside of the pickup tube. The car had sat for so long that the inside of the pickup tube had rusted into chunks of crap. By too long, I mean seven to eight years, in my garage. So, I tried to get it running, before changing things to new. Any details, ask.

So, I've redone new clips, cap and rotor, plug wires, plugs. Have a fuel filter on order, but waiting for it. I took the old filter off, and using carb cleaner, I rinsed it out the best I could. I can't imagine it being the root of my problems.

Today, I decided to change over everything. From my other 86, I changed everything from the exhaust manifold to the rear bumper. Mind you, when I took off the turbo housing from the exhaust manifold, there was a significant amount of fuel at the connection. Raw fuel. Wet. Smelly. I know this should not be there, but I don't know why it was. So, I put on the other turbo, housing, etc... Excited to have my problem solved, and to no avail. Surely, I've left things out. Please help. hehe

[Fuze]

Sounds like it could be an ignition problem if you are running a stock fuel system and it's flooding the motor that badly. At this stage it's time to test and isolate the problem down to one system and try to zero in on it.

 

Before more cranking and flooding of the motor, change out the oil and filter for fresh oil and a new filter because it's likely it has been contaminated with fuel. No need to hurt the motor.

 

Check for spark, if spark is good, check the timing with a timing light.

 

If spark and timing are good and you feel like the ignition system is working, check all the sensor connections and wiring on the intake manifold and throttle body for faults and breaks.

 

One thing that will cause the car to flood is a bad ECU coolant temp sensor (or wiring) near the thermostat, one temp sensor is for the temp gauge, one is for the ECU. If you're not sure which is which, pull one out and drop it in a cup of boiling water with the wiring connected and turn the key to ON. If the temp gauge doesn't move, you found the ECU temp sensor. Connect it to the wiring for the gauge sensor and see if the temp gauge moves. If it doesn't, it is probably faulty so swap it out.

 

I'd start there. I know 86's are a different animal as far as the fuel system and I'm not as familiar with them...

[scott87star]

I would also pull the top hat (fuel rail) off and look inside, my flatty had so much rust in there that one of the injectors was welded in place and had to be sacrificed. I couldn't believe the car was even running.

[BandY]

Quote:

One thing that will cause the car to flood is a bad ECU coolant temp sensor (or wiring) near the thermostat, one temp sensor is for the temp gauge, one is for the ECU. If you're not sure which is which, pull one out and drop it in a cup of boiling water with the wiring connected and turn the key to ON. If the temp gauge doesn't move, you found the ECU temp sensor. Connect it to the wiring for the gauge sensor and see if the temp gauge moves. If it doesn't, it is probably faulty so swap it out.

 

Here's the thing, I was under the impression that one sensor is for the gauge, and the other is for the a/c. If the engine runs too hot, the sensor loses its ground, and keeps the a/c from being on. In my other '86, the sensor was bad, so I grounded the wire, and everything went fine. Today, in the rain, I was anxious to remove the wire that I had run to ground, and hoped it would clean things up. Nothing changed, although there might be something else I need to do, like unplug the battery for a while, or something?

[mikec]

StarQuests have multiple temperature sensors:

* the small one that is in the t-stat housing. This is an on/off switch that turns OFF if the coolant temp is way to high and kills the a/c compressor. This sensor commonly fails too - it rots away internally. If you can rotate the connector prong round-and-round, odds are this sensor is kaputt. On a cold engine, if you connect an ohmmeter to the prong and sensor body (threaded area) or to a good ground you should read pretty much zero ohms. When this sensor fails, adding a wire from the harness connector to ground will bypass the sensor and restore your air conditioning. This sensor won't affect how the engine runs though... it only connects to the a/c system.

 

* the one that feeds the dash temp display. This is also near the thermostat. 2 wires on 88-later cars, 1 wire on earlier cars. The sensor body (which is grounded to the engine) is part of the circuit. This sensor feeds only the dash display; it won't affect how the engine runs.

 

* another on/off sensor that trips when the coolant is warm. This is the sensor that tells the auto climate control when there is a little warmth in the coolant - enough that the auto climate control can engage the interior heater if needed. It also allows auto transmissions to use overdrive. On 88-later cars, this sensor is the 2nd wire of the 2-wire sensor that also drives the dash display. On earlier cars it is a separate sensor connected to the water pipes under the dash at the heater core... a real nightmare to reach/test/replace. The sensor body (ground) is part of the circuit. The wiring harness connector for these sensors (1 or 2 wire sensor types) is a basic plastic connector with no rubber boot. Other than making the transmission not use overdrive, this sensor won't affect how the engine runs.

 

* a two-wire sensor that feeds the ECU. On this sensor, the sensor body is NOT part of the circuit: the two connector prongs/wires are the only connections. This sensor reads a somewhere below 300 ohms on a fully warmed up engine, and several thousand ohms on a stone-cold engine. The ECU uses this resistance reading to 1) know when to implement "choke" mode on a cold engine and raise idle RPMs and 2) to richen the air:fuel computations on a cold engine to aid the choke mode. This sensor is the one screwed into the intake manifold near the oil dipstick; it's connector pins point straight up. The wiring harness connector is supposed to have a squarish rubber insulator boot on it; on many StarQuests this is long rotted away. To make sure your car has the right sensor (and not a 88-later style 2-prong one from the t-stat area) just unplug the connector with the engine off and cold. Measure the resistance between the two prongs; it should show some value of several thousand ohms. Then measure from either prong to ground - you should see infinite ohms (open circuit) if the sensor is the correct one. The other non-switch style temp sensors will always show some finite resistance from the prong to the body/threads of the sensor and will read infinite ohms from one prong to another if they have 2 connector prongs. When this sensor fails it typically reads a too-high resistance which the ECU interprets as "engine is still cold... run extra-rich to help it while it warms up." This is too rich for a fully warmed up engine and you'll experience "bucking" at higher throttle openings - especially under boost.

 

* 2 coolant temp sensor switches at the bottom of the radiator. These are switches that trip at specific temperatures to enable the fans when necessary. As with the other "switch" style temp sensors, they use the sensor body (grounded to the radiator which in turn has a ground wire attached to it near the top/center fan mounts) as one of the terminals.

 

* On 87-later cars the airflow sensor (AFS) assembly contains an air temperature sensor. On earlier cars I think it's screwed into the OVCP, I don't remember for sure as I've had little dealings with the pre-87 models. Maybe all have the temp sensor in the AFS and the 86 cars have an added one in the OVCP... the 86 was a unique animal. Anyway, there is at least one air temp sensor somewhere on StarQuests!

 

Those are the engine temp sensors. There are also several interior temp sensors for the auto climate control system but those obviously don't affect how the engine runs.

 

mike c.

[FRO]

Hey guys:

i went to help out BandY and this is what is going on. When the engine starts, it starts fine and idles down a bit, Then I begin to see and induction of voltage that jumps sporadically,wildly. As to say that when i have a digital volt meter, testing the battery, with the engine not running i get a steady 12.7 volts. as the engine starts, within 2 seconds, the voltage jumps wildly, 13.5-9.2-0-15.8-12.2-8.4...etc.

 

We have swapped the coil, knock sensor, battery, and pulled the belt off of the alternator.

 

We have reinforced the ground to the chassis and to the engine.

 

What else could be causing this type of induction??

 

It has me stumped.

 

 

Thanks in advance for your help..

Jeff

[bender 702]

For whatever it is worth ... maybe the diode pack in the alternator is going or possibly an intermittant short somewhere... Just a thought... good luck!

[Fuze]

StarQuests have multiple temperature sensors:

 

mike c.

 

Thanks for breaking it down all the way! One other symptoom of a bad ECU temp sensor is the car won't start when hot, just the specific one I ran into.

[BandY]

Still not able to be driven. Today, I totally disconnected the alternator. No change. Took the block ground off, and did a thorough cleaning of it. No change. Disconnected the starter wires, cleaned and reattached them. No change. I took the ECU down, and felt the fuel pump relay, to see if it is what is clicking, and it is. Basically impossible to tell if the pump quits, then the engine, or if the engine quits, and then the pump. It's a fraction of a second. Could be either one. I'm not sure if the voltage issue is related, but I'm sure hoping it is. Once I can figure out what is making the voltage meter hop all over, when the engine is running, maybe the fuel pump relay will be able to stay on. It starts right away, and runs smooth idling, but after about four seconds, it dies. If I keep the accelerator pedal moving, I can keep the engine running, but I HAVE to keep changing the RPMs, or it will die. Meanwhile, the digital multi-meter is simply going berzerk on the voltage setting. Readings of 6 volts to 16 volts, and every single number in between. Changes so fast, there's never any single reading. Are there any tests in the FSM that I can go through. I'm debating on dropping a carbureted V-8 in the other 86, so I can actually have an engine that RUNS.

[scott87star]

Did you also clean the chassies ground? Negative battery wire runs first to the chassies, then to the block.

[importwarrior]

if you figure this out i know someone else having the same issue.

 

just to test can you wire the fuel pump directly maybe to see if the car runs smoother? or just stays on ?

[BandY]

I did clean the chassis ground, and the block ground, too. Cleaned the starter wires. No change. I'm not sure if the tailpipe still has a ground on it, but I'll look tomorrow. If there is not one, then I'll add it. Tailpipe is not factory, and I have no muffler. Just a straight tailpipe. Edited January 31, 2015 by BandY

[scott87star]

I think you've tried disconnecting the main to the alternator, try disconnecting everything (the plug in the backside and the main).

[tsi_tom]

Still not able to be driven. Today, I totally disconnected the alternator. No change.

 

Does the voltage still jump around when the alternator is disconnected? And totally disconnected to me means the belt is removed and the connections to the alternator are removed.

[BandY]

Yes. Belt off, and the wire off, along with the plastic plug disconnected. Made no difference.

[BandY]

About the fuel pump, once again I used the jumper wire and the engine still stalled. Pump kept running. So, I'm assuming that whatever is making the volts go crazy is telling the ecu to shut off the spark. Once I make sure the tailpipe is grounded, like it is from the factory, I'll be out of ideas.

[scott87star]

Not holding my breath that adding a tailpipe ground will fix things. Disconnect your battery AND alternator and run some jumper cables to another vehicle, start and check voltage.

[tsi_tom]

Hey Scott...

 

What I don't understand is how the voltage could jump higher than 13 volts without the alternator. The only way I could think of is the coil is injecting high voltage into the power system.

Edited January 31, 2015 by tsi_tom

[scott87star]

Of course it should be physically impossible to go higher than battery voltage without the alternator. That being said there could be some measurement error in the DVM (overshoot because the voltage is swinging so rapidly) or the battery is failing in a unique way. That's why I suggested the jumper cables above, take the whole vehicle charging/storage system out of the equation and see what happens.

[tsi_tom]

Of course it should be physically impossible to go higher than battery voltage without the alternator. That being said there could be some measurement error in the DVM (overshoot because the voltage is swinging so rapidly) or the battery is failing in a unique way. That's why I suggested the jumper cables above, take the whole vehicle charging/storage system out of the equation and see what happens.

 

Only way to raise the voltage is then via a transformer(coil). I thought about the battery too, but Jeff said they swapped the battery. Maybe it isn't a voltage problem but a volt meter problem.

[tsi_tom]

Did you have the injectors cleaned? I sent my off to rceng.com and this was the report:

 

http://i1069.photobucket.com/albums/u467/tsi_tom/The%20Missouri%20Project/Fuel%20System/ConquestGreenInjector_zpsd4309fac.jpg

 

 

 

http://i1069.photobucket.com/albums/u467/tsi_tom/The%20Missouri%20Project/Fuel%20System/ConquestBlackInjector_zpse777a7a2.jpg

 

If I remember right the 86 has two black injectors that spray together during idle and above. I don't think your injectors would be clean anymore after sitting for 7-8 years.

Edited February 1, 2015 by tsi_tom

[BandY]

Actually, these injectors didn't sit at all. These ones came from this car, but at one point, I had borrowed them for my other '86. Once I parked the other car, I took the injectors out, and returned them to this original car. I've run so much cleaner and sea foam through them, that they no longer drip or anything. Car starts up right away, every time, so cleaning the injectors isn't a priority at the moment.

 

Today, I finally solved the problem with the crazy voltage issue. Somehow, I realized that the headlights and parking lights would not come on. I looked through the normal causes for such a thing, and they still would not come on. Removed the battery, and then the fusible links shield (for the four links behind it). First, I pulled each of the three 5 amp fuses, and they all looked fine. Then, I removed the fusible link marked HEAD/TAIL, and checked it for continuity. Tested fine. Cleaned up the connectors, and tightened them a little. Put the link back on, and started the car, before putting the battery back in. Volts read 14, with very little variation. Put the battery back in, and volts still read fine. So, one of those eight connections are now making proper connection.

 

Went through the ISC/TPS reset, and it still runs incorrectly, like it did before. When I was setting the TPS voltage to .48 +/- .003, I could not get the volts to go higher than .47. The only way it would read higher, is if I open the plate up with the throttle cable. Since .47 is within specs, I finished the rest of the reset. Setting the idle at 750 is not exactly easy, because it refuses to run at one specific idle. I think I must be doing something wrong, or maybe the 1986 FSM is stating something wrong with the ISC/TPS reset format.

 

So anyhow, I drove the car to somewhere with a public wifi, in order to log in here. haha Still need to fine tune this thing.

Help is always appreciated.

[BandY]

Did the proper ISC/TPS reset today, and it made a world of difference. Something is STILL wrong, making the relay click back and forth, but once warmed up, it's a lot rarer than before. The FSM for 1986 has the ISC/TPS reset procedure, but something isn't correct, and it screws up the entire outcome. So now the car starts right up, and idles great. As long as the relay behaves. While driving, I still have virtually no boost. Not that the gauge is correct (factory), but seemingly, the gauge corresponds with the behavior. Anyhow, I did this procedure, and it was successful the first time.

 

http://www.starquestclub.com/forum/index.php?showtopic=28069

 

 

The one I went through is the one posted by chiplee.

[importwarrior]

Glad you posted the fix! Thank you very much.

as always check the flapper tension from the waste gate arm.

the arm needs to have tension and i use pliers to pull it so i can

attach it to the flapper on the turbine. if not tight little to no boost.

[BandY]

Update to this, I actually did put a different three hose wastegate actuator on, since the other one had an arm that seemed bent. I set the arm so that when everything is cold, the arm barely reaches the tiny lever. If I move the arm, towards the back of the car, there's a lot of resistance, as mentioned, but it is possible. How vital is this adjustment? Where it is now seems to have maximum effect, but I might be wrong. It's an '86 car, so it came with a single port wastegate actuator. I went with three port simply to get the ten pounds of boost, instead of seven. The way it runs now, I don't get any boost, unless I run the RPMs way up, and dump the clutch like a 16 year old kid. As I've said in another thread here, it usually is running terribly rich. Smells strongly of gasoline, and smokes, when I try to speed up in what seems to be open loop.