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Just another analogy...
GM direct ignition systems (waste spark Ignition) 2.8/3.8L used to be towed in with a no start.
The reason for the no start was a faulty ignition module.
The cause of the ignition module failure was caused by an open ignition wire or high wire resistance.
If only the module was replaced it would die again in short time.

You have to find the cause of your SMEC failures, I am trying my best to help with that to uncover the mystery.
 

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Discussion Starter #43
Just another analogy...
GM direct ignition systems (waste spark Ignition) 2.8/3.8L used to be towed in with a no start.
The reason for the no start was a faulty ignition module.
The cause of the ignition module failure was caused by an open ignition wire or high wire resistance.
If only the module was replaced it would die again in short time.

You have to find the cause of your SMEC failures, I am trying my best to help with that to uncover the mystery.
I agree, that's why at this point, I'm actually trying to force a failure of the newest smec, and hopefully, it will point me in the right direction if I can identify a burnt up circuit. The old smec is in really bad shape tho

I'm curious of the dim noid light. 2.8/3.1 gms also had problems with injectors shorting out when hot. I plan on ohming them when hot

Otherwise, everything on code 42 has been checked. The couple spots that have slightly higher reference voltage has to be checked too
 

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At this point you need to verify that...
1)No controller ground circuits are shorted to voltage and all have less than 5 ohms continuity to ground.
2) All power feeds into the controller are showing 12 volts and have no continuity to ground.
3) Controller 5 volt and 8 volt outputs read the same at the component as they do at the controller.
4) There is no corrosion on the SMEC connector.
5) Does this harness have a connector for a 4 wire O2 sensor?
a) Is that connector compromised in any way?
6)All body grounds are connected, right side engine mount/pigtails from - battery cable.
 

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Discussion Starter #45
At this point you need to verify that...
1)No controller ground circuits are shorted to voltage and all have less than 5 ohms continuity to ground.
2) All power feeds into the controller are showing 12 volts and have no continuity to ground.
3) Controller 5 volt and 8 volt outputs read the same at the component as they do at the controller.
4) There is no corrosion on the SMEC connector.
5) Does this harness have a connector for a 4 wire O2 sensor?
a) Is that connector compromised in any way?
6)All body grounds are connected, right side engine mount/pigtails from - battery cable.
1. All grounds test under 5 ohms at smec connector, no shorts to ground
2. All 12v feeds have full voltage
3. I will have to check reference voltage to components. Map/tps good
4. I cleaned connection with deoxit, but didn't have much. No corrosion evident. Will re check
5. The O2 CONNECTION was cut when I got it. I put new crimp connectors on. I will double check my work
6. All body grounds cleaned. I do not have one on the engine mount, but there is one on the back of the engine to body that I made.
 

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I would recommend that you add a ground from the R/S engine mount bracket to the body.
The factory ground strap clipped onto the bracket and to the body.
Engine Compartment Front-2014.JPG

87 used a three wire (sensor is grounded) HO2S and power for the heater circuit came from the ignition switch.
89 used a four wire (external ground) HO2S and power for the heater circuit comes from the ASD Relay.
On the four wire sensor there are two white wires, one is a ground and the other is the power feed for the heater.
On the harness side the power feed is DG/BK while the ground is BK.
The 16 gauge white wire is the power in for the heater from the ASD relay.
The 18 gauge while wire is the ground which is circuit J9 and is the ground circuit for EVERYTHING.
ELECTRICAL- Main Controller Ground 84-89.jpg 89 Daytona Turbo Powertrain 1.jpg
 

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Discussion Starter #47
I would recommend that you add a ground from the R/S engine mount bracket to the body.
The factory ground strap clipped onto the bracket and to the body.
View attachment 270199

87 used a three wire (sensor is grounded) HO2S and power for the heater circuit came from the ignition switch.
89 used a four wire (external ground) HO2S and power for the heater circuit comes from the ASD Relay.
On the four wire sensor there are two white wires, one is a ground and the other is the power feed for the heater.
On the harness side the power feed is DG/BK while the ground is BK.
The 16 gauge white wire is the power in for the heater from the ASD relay.
The 18 gauge while wire is the ground which is circuit J9 and is the ground circuit for EVERYTHING.
View attachment 270200 View attachment 270201
I ran it for about a hour, didn't die, but it does start hard when I shut it off.

Reference voltage is the same on the 5v circuit from computer to component.

However, # 52, the 8 v, is still 8.9v from the pcm and measured at the distributer harness. Injectors all ohm out at 3.1 ohms hot

I haven't had a chance to check anything else, I will look closer at the O2 sensor wiring
 

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The previous posters have way more trouble shooting experience than I but thought I's share my experience with ASD.
First, when I turned the key on no fuel pump.
It was intermittent. Long story short there was a splice on the blue/black wire i think. It looked ok but in reality the connection was not good. Another time the brown yellow ground wire to the block broke. Hope this helps.
 

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but it does start hard when I shut it off.
How many times does the engine crank before starting?
Have you looked into why?
Is the ASD being actuated as soon as the engine starts cranking?
Using a 12 volt test lamp on the + coil terminal will tell you that.
If the ASD is being actuated immediately and 12 volts is present at the coil +, injectors, fuel pump, what is missing or incorrect?
Spark, Injector Pulse, Sensor Calibration incorrect, especially the Map Sensor Baro reading?
 

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Discussion Starter #50
That's what I'm trying to figure out now too, WHY it cranks long to start warm.
I have a relay putting ground to the ASD. I am not looking ASD power, that stays constant, I've got a meter on it.

5v reference doesn't change ( map and tps)

Injectors ohm out ok.

I haven't checked the ignition sensor yet ( it's new). Orange wire is 8.9 V

My plan is to scope the injector circuit and ign, see if anything is funky there

It cranks probably 4-5 times then stumble starts. Like it's flooded. Flooring the pedal helps it start
 

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It cranks probably 4-5 times then stumble starts. Like it's flooded. Flooring the pedal helps it start
Flooring the pedal (TPS Voltage Over 2.50 Volts) tells the controller that the engine is flooded, it then goes into "Clear Flood Mode" and stops pulsing the injectors until the condition clears.

So you bypassed the controllers ASD Relay Ground?

1)What is fuel pressure reading while cranking during the no start condition?
a)Does fuel pressure hold steady on shutdown?
2)With your scanner do you see a crank/rpm signal when cranking during the no start condition?
3)Is power present at the + coil Immediately when you are cranking the engine during the no start condition?
4)Are any of the spark plugs showing any signs of fouling?
5)Is your Baro reading (Key On/Engine Off) = to actual Barometric Pressure?
 

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Discussion Starter #52
Flooring the pedal (TPS Voltage Over 2.50 Volts) tells the controller that the engine is flooded, it then goes into "Clear Flood Mode" and stops pulsing the injectors until the condition clears.

So you bypassed the controllers ASD Relay Ground?

1)What is fuel pressure reading while cranking during the no start condition?
a)Does fuel pressure hold steady on shutdown?
2)With your scanner do you see a crank/rpm signal when cranking during the no start condition?
3)Is power present at the + coil Immediately when you are cranking the engine during the no start condition?
4)Are any of the spark plugs showing any signs of fouling?
5)Is your Baro reading (Key On/Engine Off) = to actual Barometric Pressure?
Pressure is 45-50 running. Turning engine off causes pressure to drop. I clamped return line, and it stayed up. Got a regulator coming

Yes, I by passed ASD ground to activate it. When it does die, I do not lose power to coil, injectors etc

Here's a plug, doesn't look too bad

The other thing I noticed, is the fan is not coming on when hot or disconnecting the coolant sensor. I have power/ground to the fan, and when I power it on , it comes on. Instead of diagnosing, I wired in a controller to come on at 190

I haven't looked at anything else yet. I tried to current ramp the injectors, but I couldn't find a setting that worked to look at the graph well yet
 

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I would not be concerned about the hard restart when warm until you get the FPR replaced.

Just so you are aware, the cooling fan normally cycles on at 210 degrees, turning the fan on at 190 may make it run too cool which will make it run richer.

No ground side control of the ASD Relay, The Cooling Fan will not cycle on, all sounds like a controller ground issue.

Connect your scanner and start the car and watch coolant temp and fan request at 210 to see if the controller is requesting the fan to turn on or if the controller is seeing correct engine temp.

CTS VOLTAGE CHART 2.jpg
 

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Discussion Starter #54
Finally had time to test drive. Runs good. With the new regulator, starts better warm, but still cranks 5-8 times before firing. Have not look at data yet. Smec is still bypassed on the ASD circuit.
 

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Just because the ASD is actuated does not mean that the pump is actually creating fuel pressure.
Connect your fuel pressure gauge and see how long it takes pressure to build cranking.
 

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Discussion Starter #56
Just because the ASD is actuated does not mean that the pump is actually creating fuel pressure.
Connect your fuel pressure gauge and see how long it takes pressure to build cranking.
I did do that a month or so ago, it did drop, and the fuel.pressure regulator was replaced. It then didn't drop. I will recheck, thanks
 

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If fuel pressure builds immediately as it should then you have to determine if...
1)Spark is present on initial crank to start
2)Basics such as Cam/Ignition timing are correct
3)All Data inputs to the controller are correct such as coolant temp, barometric pressure, manifold pressure, throttle position, etc.
 
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