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1996 Eldorado ETC
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33 Posts
Discussion Starter #1
If interested, I posted a 'hard start after 12 hours' post just over a month ago. I thought, after replacing fuel pump, filter and swapping in a used rail and injectors, I'd cured it via a new Fuel Pressure Regulator.

Unfortunately, in past two days, it has started taking 2-3 times of cranking for it to fire if it has sat even 10 mins. I've measured fuel pressure and while it will drop, it'll have 20 plus lbs of pressure and still not fire immediately.

It'll start if I turn off and immediately try it.

Idles Fine.

Runs fine, pulls hard.

NO CODES.

(I will get a 1350/1375 if I crank it for an extended period and no start, but those go to history as soon as I restart.)

I even just spliced in at least one of the connectors at the ICM thinking maybe it had a weak spot right at the connector. NO change.

Could Ignition Control Module be 'weak'? Or are they either 'good or bad'?

Same thing with the coil packs? I've had no 'skips/misses' and it has new plugs and relatively new plug wires on it.

Any help? Ideas? Suggestions?

Thanks,
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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68,513 Posts
Fuel pressure spec, key on, just after the 2 second prime test is 41 - 47 psi. It should maintain at least 40 psi while cranking (fuel pump is commanded ON during cranking, as the engine starts and comes up to idle speed the pump is latched ON by the PCM). Running pressure is over 40 psi.

Try this: After your OFF time, turn the key ON for 5 seconds, OFF for 5 - do this 3 times to try and build prime pressure. If the engine then starts pretty quickly there's a problem with the (should be Robert Bosch, Germany) FPR.

If the key ON pressure builds to 41-47 but drops rapidly at key OFF then it's either the FPR or the fuel pump module delivery side check valve. Your fuel pump module work requires a tank drop.
 

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1996 Eldorado ETC
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33 Posts
Discussion Starter #6 (Edited)
I may have thrown a red herring at you with the 20 lbs/no start comment. I meant when I first walk out to try it, after it has 'been sitting', it might have 20 lbs on the gauge. It goes to 45lbs+ with key on. It maintains around 40-42 lbs when running. I've seen it read 5 lbs and lower (after sitting) just before i first turn the switch on and it will start. i.e. it can be very low, i turn key on, it goes to 40+ and it starts. WHEN IT STARTS.

The system pressurizes fine.

BUT OTHER TIMES: It can have 40+ on it (key off) when I try it (key on, start) and sometimes it just doesn't fire the first time. sometimes it will take 2X, sometimes it will take 5X.

Like a lot of things in life... sometimes it does and sometimes it don't.

I've pretty much changed entire fuel system at this point. But if it is electrical, it is 'sporadic' at best and isn't following a 'consistent pattern' that I can get a grasp on. I don't want to just keep chasing without a legitimate direction.

Crank sensor seems to be more toward 'stalling' rather than hard start based on the posts I can find, but I'll throw it out as a 'query' to the group.

I even swapped in a used ignition module, but no change that I can observe/document.

I can only interpret about 30% of the explanation of the starting cycle about how it passes the process from the PCM to the ICM (or is it the other way around?). So I'm not sure if there is a possible issue with the 'electrical cycle' on starting.

I'm perplexed enough that I'm actually thinking about taking it to a dealership. But other paying the bill, where is the challenge in that?

Thanks for any help.

EDIT: First time I've seen this one, but it threw a P0322 today after I just 'held the key to 'start'' and cranked on it. It threw it in combination with the 1350/1375, but again, I do NOT get those codes if I just do 'short bursts' of cranking. It only threw it when i cranked on it straight through until it fired.

P0322 - Ignition/Distributor Engine Speed Input Circuit No Signal

- Faulty Ignition/Distributor engine speed sensor
- Ignition/Distributor engine speed sensor harness is open or shorted
- Ignition/Distributor engine speed sensor circuit poor electrical connection
- Faulty Crankshaft Position sensor
- Low battery charge
- Faulty Engine Control Module (ECM)
 

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White Diamond '03 DHS (with DTS floor shift)
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86,793 Posts
Sounds like you can rule out fuel pressure.

A faulty CKP sensor CAN cause hard starting as well as stalling. (if you replace one, replace both).
I got mine on Amazon for $77 incl shipping.
 

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2002 Eldorado Biarritz
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451 Posts
The short answer is that you likely have an issue with the 4x crank sensor circuit. The long answer is that without an oscilloscope and some testing you are unlikely to pin this down exactly without replacing some parts. If you have access to an oscilloscope and feel comfortable with that I can help. If not you can use a multimeter to rule some things out and I can help you out with that as well. If you aren't comfortable with that I would start by replacing the 4x sensor with an OE part. And if you are there you might as well bite the bullet and replace the 24x as well.

The PCM uses the 4x to determine rudimentary crank position to quickly get the engine started. By the time it is started it has collected enough data from the 24x sensor to use it for more fine ignition and injection timing. Without 4x the PCM can still start and run the car with 24x alone. But, starting may be delayed substantially. Given your symptoms and the progressive nature of the failure I would be comfortable telling you to replace the 4x sensor but, without testing it is just an educated guess.
 

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1996 Eldorado ETC
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33 Posts
Discussion Starter #9
Update: After changing my crankshaft position sensors, the 'hard start problem' SEEMS to have gone away. I always say 'seems' as I'm hesitant to ever say something is 'fixed' too quickly. if it hasn't returned in two months, I'll say THAT part is 'fixed'.

BUT.... NOW....

It is stalling at idle. Not every time, but frequently. I have a diff thread on that, but wanted to finish off on this one about the 'slow/hard start' issue. IF I don't repost here, it'll mean the CKP replacement fixed the starting problem.

Thanks for everyone's help.
 
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