Gonzo91

Diesel Not starting, turns over. Rebuilt. Any help please

63 posts in this topic

Left side drive shaft inner joint and boot is easily damaged if you disconnect shock absorbers. 

 

With shocks still attached and X frame arms disconnected outboard ends, DeDion tube can move sufficiently sideways to disconnect one drive shaft at the time. A small jack may come handy to move DeDion tube. 

 

Has anyone tried a timing light yet?

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No luck on the timing light; I suspect the voltage to the injector is too low by a couple orders of magnitude. And the flywheel was in the correct position, still keyed to the pin.

 

The wide gap on the teeth for the CPS appears to be 120 degrees ATDC. 

 

So far I think there are two issues:

1. Glow plug controller not working. 0 volts immediately after key on.

2. Fuel rail pressure sensor readings are off.

" Update: fuel pump runs and pressure on low side is 2.1 bar just before the clear lines by the fuel rail. Drops to 1.9 bar while cranking. No start but again, puffs of atomized diesel coming out of the exhaust. Checked high side fuel pressure sensor, has 5.012 volts supply and good ground, sensor voltage is 0.035 volts when fuel pump is on. Sensor reading goes to -0.086 volts while cranking, supply voltage drops to 4.868 volts while cranking. A little math shows the voltage difference when on and then again while cranking is roughly the same at about 4.96 volts. How would a faulty pressure sensor affect starting/running"

 

How would a bad high fuel pressure sensor affect things? I see on other common rail diesels that it can cause no start and poor running.

 

I'm pretty sure I'm getting high pressure fuel because of the atomized fuel being expelled with each stroke but the engine has only popped a couple times even with the glow plugs hot-wired.

Edited by mender

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I will confirm rail pressure sensor signal voltage on mine at earliest opportunity. 

 

Sensor signal whilst cranking as low as yours means near nil rail pressure. 

 

Suggest you check connector to rail pressure regulator. 

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According to your info, voltage while not cranking (low pressure pump only) should be 0.5 volts; I'm only getting 0.036 volts despite confirming proper low side fuel pressure.

 

That plus going to negative voltage while cranking rather than just going to zero seems to indicate a bad sensor, especially since it tracks with the supply voltage.

 

Will check connector.

Edited by mender

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I believe I recall mine started with rail pressure sensor disconnected. This was when I first measured cylinder compression and had to prevent engine from firing. Disconnecting rail pressure sensor did the trick. 

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Found it. My aging memory is still as good as it ever was. Engine indeed fired with rail pressure sensor disconnected.   

My apologies for the broken image links  will sort out those soon  

 

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Just an off the handle question, have you checked the ECU and SAM for good connections and cold solder joints? IF not I suggest just having a peek  and beware of discharging capacitors across pins ....I cooked my ECU cleaning the terminals using sensor cleaner and a plastic brush similar to a tooth brush.   But my SAM had a whole row of dead badly connecting solder joints.  Just a thought?

 

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So far all connectors look good, have had the ECU connectors off but not the SAM. No three bars of death but not getting proper glow pug controller function from what I can tell. Pulled that apart and everything looked fresh.

 

Will pull the SAM unit down and have a look.

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3 hours ago, tolsen said:

I believe I recall mine started with rail pressure sensor disconnected. This was when I first measured cylinder compression and had to prevent engine from firing. Disconnecting rail pressure sensor did the trick. 

Will try disconnecting and see what happens. I've had to do that with faulty MAFs so I could drive home so fingers crossed!

 

Found the bolts holding the regulator to the fuel rail to be basically finger tight while checking the connector; tightened but no change. 

 

I'm trying to upload a video of a start attempt, any hints? I can get pictures off my old camera but haven't tried video before. Bonus points for whoever can identify the engine in this test image:

DSCI0008.JPG

 

 

DSCI0001.ASF

 

Edited by mender

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Windows media player works with the ASF file that I included at the bottom of the last post if anyone wants to have a look.

 

 

Edited by mender

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SAM unit and connectors all look perfect. 

Edited by mender

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4 hours ago, mender said:

SAM unit and connectors all look perfect. 

Did you open it up?  If so look for a row of solder joints deep inside that go to a long thin plug or socket. Sorry can't remember plug number but it's the one i believe for the headlights etc...

IF it's good leave it alone,..lol.

The ECU and egr I think it's call the one by the batter get water inside....the speedo I haven't seen any issues with mine yet if i remember correctly. 

The ECU and EGR both had water stains in my cars. No real damages just signs they had goten wet over time...I relocated the EGR or whatever it's called to hang off the crossmember of the dash to hopefully make sure it never sees water again.

Just moving it up the firewall didn't do it.

 

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Going to get a parts car on Saturday. I had to put the car in the air so I can work on other stuff until then.

 

I'm not having any trouble with the low pressure fuel pump or headlights, which from my understanding are the main concerns with the SAM unit but if swapping parts out doesn't work, I'll certainly have a good look inside. :)

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Update: have parts car and even managed to scrounge some parts from a Smart at the local Pick n Pull. I was there to get some Integra GS-R parts but they were already gone.

 

So, on to the work today, my wife assisting.

1. Changed the fuel rail to get different pressure regulator and pressure sensor. Old rail was full of fuel so the prior regulator might not have been the issue, and fuel was getting through the high pressure pump.

Result: now reads 0.525 volts with key on, engine off so reading the pressure from the feed pump. Reading goes to 1.3v range when cranking and there was more activity from the engine. Fired one cylinder once within first rev, then sporadic firing. Not enough to get anywhere near starting but encouraging.

 

2. Changed glow plug controller.

Result: little to no apparent change, light still came on for the same length of time, about 1 second then off. Hot-wired glow plugs again, no discernible difference. Glow plug light came on when I had the glow plugs disconnected.

 

3. WD-40 into intake. Removed EGR end of hose and sprayed into hose, pointing at the intake manifold. 

Result: no discernible difference.

 

4.Drastic measures - a very light spritz of ether into the intake hose while cranking. Yes, I know about common rail and ether, hence the very cautious approach.

Result: the engine fired immediately and idled smoothly on three cylinders at 700 rpm - for about 2-3 seconds. It then dropped off in rpm, down to about 400 rpm before reluctantly quitting. About 5-6 seconds total running from start to quitting. Repeated the process and it did the same thing each time. Tried without ether and it was quite a bit closer to catching and running as compared to before the ether but couldn't. I'd estimate that it was about half-way to a successful start. Spritz of ether again, with the same idle and quit. Tried to keep it running this time with spritzes as it slowed. Although it picked up again, it wouldn't go to 700 rpm but instead was already in the dying phase. Let it quit and went from the beginning with the bit of ether, again the 700 rpm then dying. My wife reported that during these sequences, the glow plug light had come on while the engine was idling but only the odd time, not every time.  

 

5. Unplugged the fuel pump solenoid to see if it might be shutting off one lobe of the pump and causing the decline in rpm.

Result: no change.

 

6. Had my wife apply moderate throttle as soon as it started and was idling at 700 rpm.

Result: no response from the throttle.

 

Today's progress:

A. Verified that the old fuel rail pressure sensor was faulty

B. Glow plug controller swap didn't change anything, suggesting either that the circuit is working properly with both controllers or that both controllers are faulty.

C. Success in getting the engine to start and run if only briefly. This suggests several things: fuel rail pressure is sufficient to run the engine, injectors are firing at the correct time (no smoke while idling) and ECU is setting the idle speed.

 

My conclusions:

1. Injector pulse width is insufficient to start the engine, but enough to run it at an idle (briefly) once running. A squirt of fuel every few seconds to catch the engine will keep it running for as long as the supplementary fuel is provided.

2. If I can believe that the glow plug controller is not malfunctioning but is providing the correct duration of actuation, it may be indicating a possible cause of the no-start/ short idle. If it thinks the engine is already warm, it would have a very short duration. It would get that information from the coolant temperature sensor, as would the ECU to determine the correct injector pulse width to start and run the engine. If the engine isn't as warm as the ECU and glow plug controller think it is, that might explain the no-start, then assisted start and short run time: not enough fuel for the actual engine temperature.

3. Which leads me to believe that my next step is to check the coolant temperature sensor for a proper reading. Does anyone have a resistance to temperature graph for these?

 

The hiccup in this conclusion is that the engine temperature on the dash reads low, ie, no blobs. That could be fine if the ECU uses a separate sensor than the dash but I don't know if it does. Anyone know the answer to that? For those old enough to be familiar with gas engines with a manual choke, the engine sounds and feels like it just needs a bit more choke/fuel to stay running.

 

Comments are welcome, and thanks in advance!

 

 

Edited by mender

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Other things: the fan on the intercooler wasn't coming on during the running time, don't know if it's supposed to. I checked the SAM unit last week and fuse #15 was blown. I replaced it then but rechecked it today (still good) because of one person reporting that replacing his blown #15 fuse resulted in his engine starting. Didn't work on mine!

 

Also now have two block heaters, will get some heat sink grease and install one for the next run of tests to see if warming up the engine allows it to start and run on its own.

Edited by mender

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You need to load engine to provide turbo boost and sufficient increase in inlet air temperature for intercooler fan to turn on. 

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Good to know, so not indicating other problems - yet. 

 

Tried it again today after installing a block heater and plugging it in for two hours. Again, no start without ether, start and run with a spritz. I timed it more carefully: it idles at about 800 rpm now (warmer?) for about 5 seconds before gradually slowing and stopping. Total running time from start to quit is 9 seconds. Plugged the fuel pump solenoid connector back in; no change. Reading from the high pressure sensor is 1.378v when idling at 7-800 rpm and went up past 1.5 with the extra rpm when I spritzed a little extra.The voltage tracked with rpm as it slowed then quit.

 

That would indicate to me that the fuel pressure is correct for the conditions, so no issues with the fuel system. That leaves the injectors and ECU. I have a second set of injectors now but they're older than the present set, and judging from the nice even idle when the engine is running, I don't think the injectors are the issue. I will see if I can clean them and try them out; pretty clean looking now but it can't hurt. Will carb cleaner be safe to use on the lower ends?

 

Which leaves the ECU. I don't have a spare. If I did, could I just plug it in or does it need to be initialized or whatever to the car?

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All computer must be initialized by a STAR machine to allow car to see them or visa versa. I was told by someone that you also must change all 3 at the same time for it to work also but after doing mine I think it could be done seperately. As said before be very careful when cleaning the ECU....beware of capacitor discharge across pins when cleaning even when using plastic brush and sensor cleaner. It was a simple lightening flash like in a cloud when mine popped.  I have water markings inside my ECU but don't recall any real damage but I had a few green pins. I wouldn't use anything like a brush to clean them, maybe vinagar or something that may eat the green?  Not sure what would be best as a fluid that wouldn't carry a charge?  BUT sensor cleaner isn't what I would use again! It didn't eat the green on it's own as I thought it would hense the tooth brush.

 

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Sent the injectors out today to be cleaned and checked my spare set. Removed the nozzles and blew some cleaner through them, each had 2-3 sprays out of the 5 available. Used oven cleaner on the worst one and got 4 good sprays and one partial. 

 

Here's hoping that the other set was just as bad or worse! :)

Edited by mender
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Report back from diesel injector place: all injectors have an internal restriction, likely from bad fuel and/or sitting so long. They don't disassemble to clean only stick the tips in their ultrasonic cleaner. Flows are about 1/3 what they should be.

 

I'll get them back and have a quick look to see if I can clean them myself.  

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You should be able to hang them in a sonic cleaner to get into the internals without damaging the electronics of them. Mine turned out perfectly this way. Or if you do not have a sonic cleaner a simple soaking in solution may also do wonders. You have already proven that simple oven cleaner helped your spare set. My sonic cleaner was $200ish US from harbor freight the last time I went down for a visit below the border.  It's a good sized one, capable of almost submerging a 4 barrel carb.
There are many injector cleaning youtube videos where some old fart in his garden shed has done a complete cleaning without any special tooling and his vehicle runs just fine.  I look at it in the way of the semi third world folks deal with these problems....they don't have the best of the best tools etc but they solve the same problems in their own ways. And it works.


 

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26 minutes ago, Thegorillabear said:

Willys I didn't know you made videos in your garden shed? 

LMFAO.....lol.

I'm camera shy....lol

 

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