'91 1.6 NA (with alt. comp.) into '91 eco diesel body--starting problems

[Bludodger]

As the topic states... I only down graded bcause I had the n/a engine (with new head) and needed  to pull and troubleshoot the eco diesel engine.

Both cars were functioning before the swap.

After hooking everything up (I left all the Alt Comp. hook ups electrical and air off since the eco did not have the proper connections in place), The car turned over and tried to fire but only a few times while the key was not turned). Plenty of smoke out of exhaust. Smell of diesel burning. Could not keep it running tho sounded like it was choking/sputtering.

Thinking I needed to just prime everything I continued to crank. Eventually car just cranks and no combustion at all.

I cracked injector #1 and got fuel coming from pump. So there is fuel to injectors right? Rule out solenoid. and major pump problems. Injectors were new and hardly used but are 2 years old.

Intake is clear... Will check exhaust (although smoke production initially seems to indicate that is not the problem).

Observations... There is a bit of air in clear return lines, I tried to bypass the tank with a bottle of fuel before and after filter without any success (Realize the risk of bypassing the filter but I got frustrated), Used two freshly charged batteries (rule out cranking speed).

Conclusions... Air leak? (tightened In Bolt and injector/IP connections on all cylinders), Pump just needs more priming? (shouldnt the engine be giving me more response than this?) or something to do with the Alt. Comp. hookups? ( there is an air tube that I disconnected from pump near the return line, does this need to be plugged etc?).

What am I missing?

Thanks for any help with this ... I have been away from the forum but look forward to getting back into the mix now that I have more time for my true passions.

Blu

[8v-of-fury]

These Engines need three things to run, Air, Fuel, and 12v to the solenoid... well 4 things.. Compression lol

However you did say it ran fine before putting it in this car. Did you mess with the fuel pump or timing at all in the swap?

Your getting fuel at the injectors and smoke out the tailpipe.. that means the solenoid is off the list. Your getting fuel to the injectors, which means the pump is getting fuel (lol) that takes the fuel off the list. You said your intake was free, that's the last thing needed.

I am going to say that there is only one thing hindering your starting of this engine;

Glow-plugs. You've got fuel at the injectors and good cranking speed from two batteries.. they mustn't be working properly. These engine will need the GP's all year round to start whether it be 30 seconds in the winter or 3 seconds in the summer.. unless you have an amazing battery and starter you will not likely start it on compression alone.

Try using jumper cables and giving the bus bar that runs across all four glow plugs 12v directly from the battery for 10-15 seconds and see if that helps at all.

Its a possibility.. I dunno if you have tried it yet or not.. might as well knock it off the list.

Keep us updated Blu!

Welcome back to the Best Forum on the net.  

[Bludodger]

Fury-

Thanks for the quick reply. Indeed this is site/forum is the best. Great to be back.

I did not jump the glow plugs. I overlooked that as a problem once I was getting combustion initially. But you may be on to something. I will jump it just to rule it out altho something tells me its not this. I've had GP fail in past and it just isnt behaving as I remember it would if that was the case. It concerns me that the car was trying to start initially and now does nothing but crank. But thanks for the lead and I will rule that out today.

As to the timing or alterations... nothing was changed during the swap. The only thing that may have play a role is the time that the engine has sat (~ 2yrs).

So I assume that the lack of Altitude  Compensation hook ups has nothing to do with my problems? I figured it was a stab in the dark.

Thanks Again

Blu

[Rabbit on Roids]

i bet it fires right up once you hot wire the plugs...

[Bludodger]

OK... well I had a much more eventful day than I had planned but isnt that why most of us are here?

First off jumped the plugs and nothing changed.

I finally realized that the line from the filter to the pump contained no diesel. I guess the diesel coming from out of lines when i cracked injector #1 was just whatevr was left in the pump.

At some point during my day, I started thinking that perhaps the intakes were clogged and I put a vacuum to each port. Sure enough, at least a few acorns came up from cylinder 2 and 3. Looks like something was living in there the past few years. I hoped that I removed all remnants of their abode.

Next, I ran a gravity fed IV of diesel additive to the pump. I was still trying to problem shoot the lack of fuel.

Turned the engine over with IV in place and  the engine started up after a few cranks but soon went into a high rev. It was a bit concerning as I had no control of reving via pedal or manual on top of pump. Runaway? Never had it before but have
read a lot about it. I luckily was able to cut it off with key.

Probably should have stopped there for the day and regroup but I am a bit too stubborn for my own good.  At this point I disconnected the IV and reconnected the filter via regular lines. I was thinking that maybe the IV was causing the high revving. With regular diesel lines hooked up I was able to idle it but soon realized there was smoke coming out of intakes and quickly cut the engine. So now Im thinking something (a mouse house) jammed a valve open or closed. Next step seems to be a compression test... any ideas from the experts?
In addition, I sprung a coolant leak. I guess that goes along with my own hypertension that set in during this process.

Thanks for any or all input. 

[8v-of-fury]

ACORNS! oh my.. lol

So the pump wasn't pulling fuel from the tank? but it is now.. weird

Now when you say it went in to a high rev, how high.. like screaming to the point of exploding? or just a little raised? the fact that it shut down when you turned the key off tells us it wasn't a run away off an alternate fuel, or else it may have kept running.

Persistence is what makes things happen. Sitting around procrastinating doesn't lol. Hope there isn't anything to serious stuck in the engine.. Did it sound like there was a good *huff-huff-huff* noise from the intake with the one that was smoking? indicating the compression was not happening on that cylinder and half burnt diesel was making its way out the intake.

Coolant leak. Bummer. easy spot to fix? they are a pain.

I hope you get it all worked out. At least now you know your gp's are working lol.

[745 turbogreasel]

I'd guess the pump had enough fuel to start, but ran out before it had the pull to fill the filter.

Perhaps then it burned off the fuel loaded up in the experimenting for some extra RPM?

If you pull the valve cover,  and turn the engine by hand, you should be able to see if a valve is not returning all the way.

[Bludodger]

Thanks for the replies and ideas...

Fury- The revving was out of control and much higher than Ive heard one of these babies rev. I stopped it quickly... time will tell if there was serious damage done. Ideas? I did in fact hear the huffing... leading me to believe that there was something major happening. A compression check would help figure this out. Any other thoughts?

745- Thanks for the valve cover idea. simple and conclusive. I like it. Especially since I thought I would be done with this project and on the the next one last week.

Keep the ideas and thoughts coming... they are appreciated, for sure.

Blu

[Bludodger]

Also... if something is preventing the valve from seating properly and assuming it is "soft as an acorn" what do you guys think the damage would be and what would be the fix?

[8v-of-fury]

I would think if the engine ingested an acorn, there may have been higher then tolerable compression levels in that cylinder. If a few thousandths difference on a head gasket can change compression a few numbers imagine what an entire acorn can do if it were in there. However the piston may have just obliterated it against the head and shot it out the tail pipe.. lol

You would think if there was something physically holding the valve open it would have got knocked loose when it went in to the higher revs.. and get processed through the engine. Try the valve cover idea 745 posted to make sure each valve is making full travel.

The runaway you experienced worries me a bit.. if you were not opening the throttle any.. it wasn't the pump injecting more fuel to allow the engine to rev which means it was running off of another fuel source.. however when you cut power by turning off the key, and the engine stopped.. that tells us it wasn't another fuel as the stop solenoid in the pump stops fuel from making it to the injectors.

I just had a thought... if it were to be running off of its own motor oil say, it could be idling fine on the amount of diesel the pump is supplying it with.. but then add in that bit of motor oil from the valve cover vent.. and maybe it was enough to make it rev up? how much oil residue is in the intake? much? feel its consistency.. does it feel like oil.. or oil with grit to it?

Try 745's idea, then if they all check out try and run it again, this time with the valve cover vent unhooked from intake. see how it runs.. but be ready to snuff the engine out by dumping the clutch in one of the higher gears if it starts to run away and the key won't kill it.

[Bludodger]

Ill keep u posted... time to head back to the laboratory. wish me luck...lol. Looks like first I will first pull valve cover and then depending what I see, move on to compression test. Also, had a thought that  a valve could be stuck open from sitting for a few years. Has that happened to anyone? Make sense?   

[Rabbit on Roids]

one of these days one of us is going to have a runaway so bad on one of our hotrods that the clutch isnt going to stop it. VW clutches are tiny. they slip like no other when they start going out.

[burn_your_money]

The runaway you experienced worries me a bit.. if you were not opening the throttle any.. it wasn't the pump injecting more fuel to allow the engine to rev which means it was running off of another fuel source.. however when you cut power by turning off the key, and the engine stopped.. that tells us it wasn't another fuel as the stop solenoid in the pump stops fuel from making it to the injectors.

When a pump is at rest (0 RPM) the collar on the plunger that controls fuel delivery is moved to the maximum fuel position. Typically this is more then full throttle. The collar may have been stuck which caused the high revving but the fresh fuel and high rpms may have freed it enough that it can now operate normally.

[8v-of-fury]

The runaway you experienced worries me a bit.. if you were not opening the throttle any.. it wasn't the pump injecting more fuel to allow the engine to rev which means it was running off of another fuel source.. however when you cut power by turning off the key, and the engine stopped.. that tells us it wasn't another fuel as the stop solenoid in the pump stops fuel from making it to the injectors.

When a pump is at rest (0 RPM) the collar on the plunger that controls fuel delivery is moved to the maximum fuel position. Typically this is more then full throttle. The collar may have been stuck which caused the high revving but the fresh fuel and high rpms may have freed it enough that it can now operate normally.

That is NIFTY! Good to have someone who works on these things around lol. So what is the purpose of it being moved to that position to aid in starting?

[burn_your_money]

Reliability. Ever notice the nice puff of blackish smoke that comes out of an old VW when you start it up? Excess fuel. It just makes starting easier. Also as a pump slowly wears out the starting fuel also gradually decreases. By having an excess amount of fuel it allows for the pump to wear more before it needs to be overhauled because it isn't starting anymore.