Intermittent crank, no start

Good morning,

Do you have a scan tool to check for any codes?

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://www.2carpros.com/articles/car-cranks-but-wont-start

I would try some starting fluid in the air filter and see if it starts and stalls. That will tell me if it is a fuel delivery issue.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

You can remove the connector for a fuel injector and out a test light in series and crank the engine. See if the light flashes. If it does, the ECM is commanding the injectors on. If it is not, then the ECM quad drivers may be no good.

I would also check the compression.

https://www.2carpros.com/articles/how-to-test-engine-compression

Roy


Service of the PCM should normally consist of either replacement of the PCM or EEPROM programming. If the diagnostic procedures call for PCM Replacement, check the PCM first to see if it is the correct part. If the PCM is faulty, remove it and install the new service PCM.
The new service PCM will not be programmed. You must program the new PCM. DTC P0602 indicates the EEPROM is not programmed or has malfunctioned.

Notice: In order to prevent possible electrostatic discharge damage to the PCM, do not touch the connector pins or soldered components on the circuit board.

Notice: Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.

Important: When replacing the production PCM with a service PCM (controller), it is important to transfer the broadcast code and production PCM number to the service PCM label. Do not record on PCM cover. This will allow positive identification of PCM parts throughout the service life of the vehicle.

Removal Procedure
1. Disconnect the negative battery.
2. Disconnect the IAT sensor electrical connector.
3. Remove the 3 bolts from the inner fender brace and remove the brace.
4. Loosen the clamp securing the air intake duct to the air cleaner housing.
5. Carefully remove the air intake duct from the throttle body and air cleaner housing (1).
6. Remove the 2 screws (2) from the 2 air cleaner housing sections.
7. Remove the air cleaner housing cover assembly (1).
8. Without disconnecting the PCM connectors, remove the PCM and harness from the PCM housing.
9. Disconnect the PCM connectors.

Installation Procedure
1. Reconnect the PCM connectors.
2. Carefully reinstall the PCM and harness into the PCM housing (3).
3. Reinstall the air cleaner housing cover assembly (1).
4. Reinstall the 2 screws (2) from the 2 air cleaner housing sections.
5. Carefully reinstall the air intake duct to the throttle body and air cleaner housing (1).
6. Tighten the clamp securing the air intake duct to the air cleaner housing.
7. Position the inner fender brace and reinstall the 3 bolts.

The one thing I failed to mention was there were no codes, because I cleared it after taking care of a code (DTC) P0442 with a new gas cap. I don't think it's been driven enough to relearn.

Okay, there is no relearn. What is happening is the car will test the evap system and if it passes, the light will stay out.

https://www.2carpros.com/articles/how-emission-control-systems-work

If the repair was not successful, the light will return.

https://www.2carpros.com/articles/smog-test-inspection-information

I attached the flow chart for the code for you to review.

Let me know if you have any questions.

Roy

442

Circuit Description
The evaporative system includes the following components:
The fuel tank.
The Evaporative Emissions (EVAP) canister vent valve.
The fuel tank pressure sensor.
The fuel pipes and hoses.
The fuel cap.
The EVAP vapor lines.
The EVAP purge lines.
The evaporative emission canister.
The EVAP purge valve.
The evaporative leak detection diagnostic strategy is based on applying vacuum to the EVAP system and monitoring vacuum decay. The Powertrain Control Module (PCM) monitors vacuum level via the Fuel Tank Pressure sensor input. At an appropriate time, the EVAP purge valve and the EVAP canister vent valve are turned ON, allowing engine vacuum to draw a small vacuum on the entire evaporative emission system. After the desired vacuum level has been achieved, the EVAP purge valve is turned OFF, sealing the system. A leak is detected by monitoring for a decrease in vacuum level over a given time period, all other variables remaining constant. A small leak in the system will cause DTC P0442 to be set.

Conditions for Running the DTC
1. No Vehicle Speed Sensor (VSS), Throttle Position (TP), HO2S, Misfire, Intake Air Temperature (IAT), MAP, Fuel Trim, Injector circuit, Exhaust Gas Recirculation (EGR) Pintle Position, Engine Coolant Temperature (ECT), or Mass Air Flow (MAF) sensor DTC(s) set.
2. The DTC P0440 diagnostic test has passed.

Conditions for Setting the DTC
A vacuum decay condition indicating a small leak is detected during the diagnostic test.

Action Taken When the DTC Sets
The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

Important: Although these diagnostics are considered type A, they act like type B diagnostics under certain conditions. Whenever the EVAP diagnostics report that the system has passed, or if the battery has been disconnected, the diagnostic must fail during two consecutive cold start trips before setting a DTC. The initial failure is not reported to the diagnostic executive or displayed on a scan tool. A passing system always reports to the diagnostic executive immediately.

Conditions for Clearing the MIL/DTC
The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.
The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for the following conditions:
Cracked or punctured EVAP canister.
Damaged source vacuum line, EVAP purge line, EVAP vent hose or fuel tank vapor line.
Poor connection at PCM.
Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
Damaged harness.
Inspect the wiring harness to the EVAP canister vent valve EVAP purge valve and the fuel tank pressure sensor for an intermittent open or short circuit.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. If a EVAP canister vent valve or EVAP purge valve electrical malfunction is present, the purge system will not operate correctly. Repairing the electrical malfunction will very likely correct the condition that set DTC P0442.
3. Checks the fuel tank pressure sensor at ambient pressure.
4. Verifies that the fuel tank pressure sensor accurately reflects EVAP system pressure changes.

the evap code would not make the car not start. i'm planning to do more work on it today and hopefully have some kind of result. I really don't have the funds to take it to a shop right now but it may be my only choice.

Okay, keep us updated.

Roy

Okay, now here's the kick in the head: Went out election day and the car started, very chuggy and i thought it was going to stall. feathered the gas pedal and it cleared after a minute. after that it seemed like it had no problem at all. it does this about once every 3-4 months. went out wed and today started and ran like nothing was wrong. nice smooth idle. It does crank over what I think is a bit much before starting. any thought on seafoam? maybe something is sticking?

again no codes.

Disconnect the EGR valve and see if it stumbles when starting. If it is partially open, it will give you a vacuum leak and it will run rough.

Roy

update: i did an intake fog with seafoam then checked vacuum hoses. yes Roy, I disconnected the EGR. It cranked and didn't start. removed and cleaned EGR, then it started and ran beautiful. no stumbling. 2 days later (today) went to start it (reached in with the key), it barely started after winding over 5 or 6 times. coughed, stumbled. I revved it up a few times and it cleared out ran fine.

Okay, when you removed the EGR, was there carbon on the bottom holding the valve open?

Roy

there was a carbon buildup and would stick when depressed.

If that sticks open, it creates a massive vacuum leak which will cause the delayed start and the engine running rough.

Roy

I cleaned and freed up the EGR. it does not stick now.

Okay, do you still have the issue?

Roy

Today I went to start it (reached in with the key), it barely started after winding over 5 or 6 times. Coughed, stumbled. I revved it up a few times and it cleared out ran fine. it did have a random misfire and is still having issues.

Can you tell me the fuel pressure as I suggested?

Roy

I rented the tool the last time it was doing this. I do not have the fuel pressure test gauge.

Okay, let me know the results.

Roy

might be a while for that the other vehicle is down too.

No problem. We will be here.

Roy

I bought a fuel pressure tester. while key on it is 50 then when the pump stops it drops to 42 in video, holds 42 for 5 minutes but no start today. Or the whole problem could be the catalytic convertor, lol .

Okay, fuel pressure is good.


Pressure
48 - 55 psi


Unbolt the head pipe from the exhaust manifold and see if it starts easily. If it is a clogged catalytic converter, it will start right up.

Roy

Sorry Roy. look at the picture i was making a joke because the cat was under the hood helping out.

Cute. Love that picture.

Roy

So again I have a crank no start situation. The video shows it "trying" to start with audio. I have to get this fixed ASAP. the bitter cold is about to drop on me. Normally this time of year there's 2-3 feet of snow and 20 degree temperatures.

Okay, I attached the wiring diagram for the starting system.

We need to do some testing at the crank relay with a voltmeter.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

https://www.2carpros.com/articles/how-to-check-wiring

Let me know when you are ready.

Roy

to clarify it does crank but doesn't start... today. the video shows it cranking.

I would do a compression test. It does sound a bit off cranking.

You should have around 140-150.

https://www.2carpros.com/articles/how-to-test-engine-compression

Roy

12/11/20 I did not retrieve my compression tester yet. checked the fluids. 1 quart oil and some power steering fluid. It started fairly normal. let it run until it got to temperature shut it off then started right back up. revved rpm up to 3,000 it seemed very responsive, smooth idle. I decide to take it for a short drive. it seemed fine until the shift. At every shift during acceleration there was a slight stumble or cough.
normal on deceleration. got back to the driveway shut it off started up fine.

Okay, let me know when you have the compression results.

Roy

Results from compression test.
1- 140
2- 150
3- 145
4- 155
5- 142
6- 152
With fuel and spark disabled.
Began the day with crank no start, cleaned ACDelco 41-101 Professional Iridium Spark Plugs put everything back together. Cleaned 2 body grounds and it started like it should. I just noticed it has been driven 4,584 miles between April 1999 and Jan 2021. Current mileage 131,754.
I will find/clean the other grounds and order new plugs.

Keep me updated.

Roy

continued tracing the wire harness and found 7 total grounds and one that i think is a ground and was unattached tucked under the water pump bracket. Pic 1. Negative battery terminal bolt had rust on the threads. After reading another post here about the harness that goes under the battery, I took that apart and it looked good until I got to where it sneaks around the back side of the radiator fill neck. 4 cut wires from the rad cap. I plan on cutting out and soldering new wire. I will also dig up a wiring diagram to make sure that disconnected wire was a ground before reconnecting the battery. As an extra added bonus, since the inspection expired they would not let me renew the registration.

Where did the cut wires end up?

Can you post the picture of the cut wires?

Roy

The insulation was cut by the radiator cap. (click the pics to enlarge) Possibly making an electrical connection with the cap. The harness tucks between the radiator and radiator support. Wrapped with dry rotted electrical tape (no wire loom).

I would cut out the corroded wires and replace them with new wires. Solder and shrink wrap the connections.

Roy

The wire shown here is a ground? I found it tucked under the bracket not attached to anything. Black with white stripe. It comes out of the harness with fuel injectors. When i dig through my nuts i'll relocate it to a stud.

Correct. It is a ground.

Roy

I had a day where I could get the wires cut, spliced soldered with heat shrink. It started and ran normal. cranking was even better sounding. a week later February 6 as I was going to the bail box It again cranked over with no start. It sat until February 16th reached in and it started like there was nothing wrong. snow just keeps coming.

This is a tough one to help from here since I cannot see it, touch it or test it.

You will need some outside help from someone for this one.

Roy