Error code 42 (fuel pump) reoccurs after replacing everything from tank to injectors

[Otto]

I've had this problem for quite a long time now. 'Check engine' lights up one minute after startup, but the car runs fine, accelerates properly, idles smoothly and so on. The problem is getting the car running after its been shutdown for a few hours. I've to crank atleast three or four times at minimum (depending on how cold it is), and when it gets running the idle is bad. Hitting the accelerator at that point makes the engine almost choke and drops RPM:s even lower. After say one minute of idle the accelerator works as supposed and the car is ready to drive.

This far I've replaced the fuel pump, filter, pressure regulator and blown the fule line clean with compressed air. Seems to run better, but didn't help the cold starting problem.

I suspected a malfunctioning temperature sensor that gives the ECM a false reading about what the engines temperature really is. Neither did it solve the problem. The sensors gives correct values at defined temperatures in a service manual.

Anyone have further ideas about this? Have to put the car aside during the winter because I'm quite sure I won't get it running when it drops down to -20C degrees, so atleast now I'll have time to try and track down the problem further

Thanks for any ideas and suggestions in advance.

PS. My car is a n/a '92 EDM Eclipse with the 4g63 engine.

 

[Rex2342]

Sounds like your fuel pressure is bleeding off while the car isn't running or your fuel pump is going bad. Have you checked the ecu for leaky caps too?

 

[Otto]

Sounds like your fuel pressure is bleeding off while the car isn't running

Is there a one-way-valve somewhere in the fuel line, or does the pump itself take care of keeping the pressure?

or your fuel pump is going bad.

I kinda doubt that. I get sufficent pressure, even with the previous pump. But the problem is there no matter which pump I've installed.

Have you checked the ecu for leaky caps too?

Yes. I did take a peak into the ECU. Nothing visibly broken, darkened or leaked.

Last night I read about making resistance and continuity tests to the EFI relay, which I haven't done yet. I'll post further as soon as I get it tested.

 

[Otto]

Sounds like your fuel pressure is bleeding off while the car isn't running

Oh, and I forgot to mention that this is what happens. The pressure lowers when the car is off. I've thought this is just normal, like on some manufacturers cars (like Fords, that runs the fuel pump for a couple of seconds when the ignition key is turned to the ACC-position).

 

[Rex2342]

DSM's don't do that. The fuel pump only comes on while your cranking the engine. They don't need to prime. What about the injectors? Any signs of the seals leaking or the injectors themselves leaking? I had an rx7 do things similar to this in the shop once. The car would run great but after you shut it down the injectors would bleed down and flood the engine. This caused it not to start until we cleared the fuel from the chambers by taking out the spark plugs and turning it over. Yours obviously isn't this severe but could be something else to look at.

 

[ROOKIE1]

I had a similar problem with starting after shutdown . It was my ECU . I know you said you checked , but how closely did you inspect it .Mine was not as obvious as the pictures that you see on leaky capacitors . They may not be full blown but just starting to leak . Just an easy thing to check . Good luck , let us know .

 

[Otto]

DSM's don't do that. The fuel pump only comes on while your cranking the engine. They don't need to prime.

Okay. How about keeping the pressure in the fuel line after shutdown? Is it supposed to stay or go slowly down in a couple of hours?

What about the injectors? Any signs of the seals leaking or the injectors themselves leaking? I had an rx7 do things similar to this in the shop once. The car would run great but after you shut it down the injectors would bleed down and flood the engine. This caused it not to start until we cleared the fuel from the chambers by taking out the spark plugs and turning it over. Yours obviously isn't this severe but could be something else to look at.

Thanks for the suggestion! Haven't heard of such behaviour before, but unfortunately I didn't find gasoline in any of the chambers. Last time I had the car running was two days ago, but I doubt that the possible fuel would have evaporised in this time.

I had a similar problem with starting after shutdown . It was my ECU . I know you said you checked , but how closely did you inspect it .Mine was not as obvious as the pictures that you see on leaky capacitors . They may not be full blown but just starting to leak . Just an easy thing to check . Good luck , let us know .

The capasitors look all fine. I also took a macro shot of the internals while I was at it:

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Just in case someones opinnion is different. They don't look like damaged or leaked... or do they?

I'll have the EFI relay tested as soon as I get my hands on some test wires. I'll keep you up to date...

Thanks.

 

[steve]

The capasitors look all fine. I also took a macro shot of the internals while I was at it:

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Just in case someones opinnion is different. They don't look like damaged or leaked... or do they?

I'll have the EFI relay tested as soon as I get my hands on some test wires. I'll keep you up to date...

Thanks.

Somebody worked on that ECU in the past. Those aren't original capacitors and the factory didn't trash the board like that with glue. So the originals ones likely leaked. At this point it hard to say if they fixed the typical causes for the that your describing.

I do hate when people flood the bottoms of the caps with crap you have to pick away to fix the stuff they glossed over. It pretty much trashes the ECU.

Steve

 

[Otto]

Somebody worked on that ECU in the past. Those aren't original capacitors and the factory didn't trash the board like that with glue. So the originals ones likely leaked. At this point it hard to say if they fixed the typical causes for the that your describing.

I do hate when people flood the bottoms of the caps with crap you have to pick away to fix the stuff they glossed over. It pretty much trashes the ECU.

Steve

That's just terriffic, though it's good to know. I removed the circuit board from the housing and yes, I am convinced that those arent soldered at the factory I wonder what the original values have been? And which type of capacitors? Normal polyester film capacitors (like the ones on currently there) or something more exotic? I might just aswell try replacing them, though they don't look worn...

 

[steve]

I doubt changing the caps is going to help they aren't leaking but the originals did. The board has had pretty extensive repairs to fix the corrosion damage but it sounds like there may be more.

Other than the hot melt the works doesn't look bad.

What does the ECT and IAT sensors say before starting the engine.
Do you get any other codes?
What are you using for a datalogger?

Steve

 

[ROOKIE1]

Good lord son , looks like they had an orgy in there . How could you possibly tell if they leaked ? How does the bottom of the board look .

 

[Otto]

What does the ECT and IAT sensors say before starting the engine. Do you get any other codes?

I've to check those. I've had more codes, but this far I've narrowed them down to only number 42. I'll see if I can get other codes now. It's a while since I last checked.

And btw, what does ECT stand for? Electronic something temperature? English ain't my own language and things tend to be called a million different abbreviations

What are you using for a datalogger?

Tunerstein with a DIY-cable.

How could you possibly tell if they leaked ? How does the bottom of the board look .

I teared the glue out of there (which came off very smoothly in a couple of bigger pieces). The board itself doesn't look damaged at all. The current caps neither look at all damaged from any side.

 

[Otto]

What does the ECT and IAT sensors say before starting the engine.

I suppose ECT is engine coolant temperature. It gives a reasonable resistance, aswell as the intake air temperature sensor. But where does the coolant temperature wire go? To the EFI relay? Didn't find a pin for that in ECU schematics...

Do you get any other codes?

No. Went out for a ride and didn't catch anything else.

 

[Auto RS T]

I suppose ECT is engine coolant temperature. It gives a reasonable resistance, aswell as the intake air temperature sensor. But where does the coolant temperature wire go? To the EFI relay? Didn't find a pin for that in ECU schematics...

No. Went out for a ride and didn't catch anything else.

ECT (Engine Coolant Temp) is pin 20 to the ECU. The sensors ground is pin 24.

The FSM shows a resistance test to check the ECT sensor.

@20*C (68*F) 2.45 +/- .24 k ohms
@80*C (176*F) 296 +/- 32 ohms

Even though the DTC is code 42 this really sounds similar to an ECT sensor issue... I will continue to follow this thread.

Remedys for code 42 are harness and connectors and the EFI relay.

I re-read the thread and saw in post 1 that you have allready tested the ECT sensor (pins form a "T" on the sensor) but I still wanted to leave the information.

 

[Otto]

ECT (Engine Coolant Temp) is pin 20 to the ECU. The sensors ground is pin 24.

Okay. Must've missed that in the pinout list...

The FSM shows a resistance test to check the ECT sensor.

@20*C (68*F) 2.45 +/- .24 k ohms
@80*C (176*F) 296 +/- 32 ohms

Even though the DTC is code 42 this really sounds similar to an ECT sensor issue... I will continue to follow this thread.

Yea... I've tested those directly from the sensors contacts. But have to make sure that there's continuity to the ECU.

Remedys for code 42 are harness and connectors and the EFI relay.

The EFI relay was successfully tested.

I re-read the thread and saw in post 1 that you have allready tested the ECT sensor (pins form a "T" on the sensor) but I still wanted to leave the information.

No problem. Any reasonable suggestions and ideas are welcome at this point...