Would a Stuck Turbo Wastegate cause a no-start w/huge black smoke?

[Bruce_De_Mille]

My 1994 C2500 Suburban all of a sudden wouldn't start the other day. It actually "tries" to start for about 1-2 seconds, blows a huge black smoke cloud, and shuts right back down. Temp was +/- 60 degress. I let the glow plugs cycle on & off a few times and tried again ... same problem. I noticed I could't move the wastgate arm at all, (even after an overnight Liquid Wrench soaking) so we pulled off the GM-4 Turbo. Even cold, the GM-4 impellor thing doesn't seem to have much play. After Turbo removal and "working" : the wastgate control arm I finally got it to work pretty good. In the meantime, I replaced all the Glow Plugs and will also replace the Fuel injectors once the install kit arrives. Batteries are both about 6 months new but I will put the trickle charger on tomorrow just to make sure they are ok. I will also clean up the 2 neg battery connectors tomorrow.

My question(s) are: 1) could the stuck wastegate controller cause all the black smoke and a no start condition? 2) Will the actuator just freeze up again real soon? (it seems expensive and silly to replace the whole turbo just because the wastegate got stuck!)

I'm also thinking about changing out the GP Relay/Controller since the intial cycle time seemed much shorter than it used to be.

I'm really, really, really hoping the IP hasn't gone bad. I recently had the IP replaced on my other Suburban 6.5TD (the 1999) and got hit for just over $2,000 for the repair!! Big ouch for me, I don't have that kind of moola.

All suggestions really appreciated.

PS I have a Multi Meter and now may ned to learn how to use it. I'm also going to order a vacuum tester which I will also have to learn.

Bruce De Mille
Lakewood Village California
1994 Chevy C2500 6.5TD Suburban
1999 Chevy C2500 6.5TD Suburban

[Hubert]

No in and of itself a stuck wastegate won't cause a huge plume of black smoke at start up. As long as the turbo is spinning freely and cat isn't plugged etc etc. It should breathe enough to get going. The 6.5 if properly warmed with glow plugs or warm enough already and it spins fast enough and gets a little fuel should start within seconds of starter spinning.

You commented that the turbo did not have any appreciable play but did it spin freely. A good turbo you can spin the blade really easily. Air filter isn't really dirty is it or any intake obstruction?

Off (no vaccum applied) the wastegate you should be able to push open so there does appears to be a problem.

Make sure you have fuel to the injection pump, then fuel at injectors, power to glowplugs, it spins over fast and report back at what all you have replaced and mods of the truck. In your signature give a little more info about the trucks milage mods etc.

[Bruce_De_Mille]

Thanks Hubert,
On this 1994 Suburban I have an Amsoil air filter and did the John Kennedy Air Box mod's years ago (removed snorkle and inlet cone) . The Amsoil Air Filter was cleaned at the last oil change and appears okay now. I don't see or feel any obstruction on the inlet side. With the snorkle gone it should be a lot less restricted. I have a John Kennedy exhaust system and no cat at all so I do not think there could be any exhaust restriction (plus it seems to blow a huge black could out the exhaust with no problem at all!)

The turbo spins very freely and now the wastegate actually moves back and forth with ease. No indication of any problem with the turbo. I do have a new-in-box GM-8 that I had in stock that I can substitute if need be.

This 1994 Sub has been just a little harder to start over the last 6 months (than my 1999 6.5TD). I typically have to hold it in the Start position a little longer to get it to go. I figured it was going to need a new set of glow plugs (which I just replaced yesterday). All the old Glow Plugs were fine with no melted tips or any other problems other than a set of smaller hands would have been helpful! I did notice that the dash glow plug light seemed to cycle off a little too quick initially (after about 1 second). I disconnected the Coolent Temp Switch in the water crossover and I got a longer cycle time (dash glow plug light stays on longer) but still no start & big smoke. Based upon the initial short cycle on time (about 1 sec) the Glow Plug relay might be suspect. It has never been replaced since I have owned it over the last 5 years and 50,000 miles.

To eliminate an injector problem I have a new set of Bosch injectors ready to go in. I'm just waiting for the install kit to arrive before I can do that. Once I have the passenger side injectors replaced then I will put the turbo back on and give it a go.

From what I've read I don't want to replace the injectors on both sides due to getting air in the system(?). I've never replaced injectors before but I do have the Lisle #30500 30mm socket in stock so it's probably time to replace them. I don't want to take one problem and potentially turn it into multiple problems!!

The fuel filter is fairly new but I will put a new one in today and I'll run the charger to keep the batteries up.

After I get this all back together and ready to try again, I will ask the next question .... how to determine if I have fuel to the injection pump?

Thanks,
Bruce

Bruce De Mille
1994 Chevy C2500 6.5TD Suburban (secondary vehicle)
166,000 miles (purchased at 117,000 miles)
John Kennedy Air Box Mods
John Kennedy Exhaust System
John Kennedy performance chip
Remote mounted PMD (in front of battery)
Amsoil Air Filter
Baldwin Oil & fuel Filters (always)

1999 Chevy C2500 6.5TD Suburban (primary vehicle)
112,000 miles (purchased at 50,000 miles)
Remote mounted PMD
Baldwin Oil & fuel Filters (always)

[Bruce_De_Mille]

FYI no codes were set.

[DmaxMaverick]

Welcome aboard, Bruce!

The sounds like your turbo is fine. It won't have any effect on startup as long as air can get through it. It does nothing until you put a load on the engine. If you are able to get plumes of black (or any color) smoke out the exhaust, it's fine, too. Black smoke means the GP's are working and compression is sufficient, as well. You need significant heat to make black smoke. If everything is where it should be, and flowing, that leaves the injection pump. One indicator of IP failure is copious amounts of black smoke. You have more fuel being injected than can be burned in an otherwise healthy combustion chamber. If it comes down to it, you should be able to replace it yourself for way less than $2,000. More typically ~$800. Even less if you have a good relationship with a local Stanadyne shop. TDP Advertisers offer competitive prices. If you know your way around an engine and can turn a wrench, you can do it yourself fairly easy. We can help.

On a side note:
Excellent vehicle descriptions. Do yourself (and everyone trying to help you) a favor and take all that vehicle info and paste it into your signature. Go to your User CP (link at upper left of nearly every TDP page), select Edit Signature (top of the list at the left of the CP page), and plug it in there. It will then be a permanent part of all your posts (unless you deselect it). Let me know if you need help with that.

[Bruce_De_Mille]

Thanks DmaxMaverick,
I've been a DP member for quite awhile but never posted anything (didn't really know how to "work" the forum other than read all the posts!). If it wasn't for Jim Bigley and the Diesel Page books and this forum I probably would have got rid of the 6.5TD a long time ago.

Since you feel (as I do) that my original GM-4 turbo is probably okay, I think I will clean it up a little and put it back on (instead of using the new GM-8). My only concern is: 1) what caused the wastegate to get stuck? and 2) how can I prevent it from getting stuck again????

Since I am still paying off the last IP pump (done on my 1999 6.5 TD about 4 months ago) I think I may do this one myself (if the worst case happens and I have to replace it ). (Wow, I even got the horrified Smiley Face to work !) I will do all the other possible minor causes first (injectors, PMD, new fuel filter, and anything else I can think of). I have a newer 5521(I think that is the latest & greatest?) on the shelf that I had tested okay at a local shop a few years ago. I will probably use it after having a local Stanadyne shop test it again. I just re-read the DP Removal & Replacement Guide (re: the IP) and I think I'm sure I can do the wrench work. I just need help with the BRAIN work!! (and will undoubedly ask a lot of questions that will get more experienced people a laugh). Anyway, still hoping and IP replacement is not necessary!

I think I got my vehicle info to work on the signature portion.

Thanks for the help!

[DmaxMaverick]

That 5521 may not be compatible with your '94 ECM. Still, updating the ECM is much less expensive than getting a new/reman pump for the 1994 (and, since you already have one). The 1994 had a unique ECM requirement, not completely compatible with later pumps. If you have it on the shelf, get it in with a set of new/reman injectors (highly recommended) and get down the road. Kennedy and other TDP supporters can easily help you with the electronic compatibility if necessary. In any case, it won't cost you anything more to try it first. Some work, some don't.

If you have a good IP that tested good a few years ago, there shouldn't be a need to test it again. As long as it turns and isn't obviously contaminated, I'd just install it. They have a good shelf life if they are stored properly.

Hard to say why your WG would freeze up. Could be corrosion or soot build up inside. If it's free now, with not too much play, it should be good 'til the next time. Give it a squirt of WD-40 every once in a while, and it should be fine. Wastegate failure is rare. That said, I'd replace it with your GM-8 before burning up too many brain cells on the -4 if you have further problems with it.

[Bruce_De_Mille]

DmaxMaverick

In any case, it won't cost you anything more to try it first. Some work, some don't.

So if I understand you correctly, you are suggesting to just put in the new injectors and new IP and give it a try. If it does not work then call JK about a new/updated ECM. What will the symptom be of a mismatched ECM and 5521 pump (i.e. balls of fire, mushroom clouds or just won't run?) ??

Thanks!

[DmaxMaverick]

It will either not fuel the injectors at all, or will start and not get out of limp/default mode. This is assuming everything else is healthy. Yes. I'd plug them in and go for it. Worse case is you'll be right where you are now, only smarter with more experience (and some dirt under your fingernails).

[Robyn]

The 94 should have a 5068 IP on it. It must have a ECM and a Prom update or its gonna be a sad sack.
Speak with John Kennedy or Bill Heath about the swap.
Its done all the time and you may only need to swap the prom to get it to work right.

I have a 5068 on my 94 and am thinking of swapping to a 5521 and a performance chip.

Good luck with the little creature.


Robyn

[Jim Faire]

Bruce doesn't say if his 'burb is an 'F' or an 'S' ... not all 1994s came with the dreaded 5068, only the 'F' engines and only the early ones, at that.

I wouldn't worry about updating the ECM until I found out whether my IP was a 68 or not.

In any case, the 4-digit ECM code will tell either John or Bill what IP it's for.

[Bruce_De_Mille]

My '94 is an "F" (8th digit of the VIN I think) and the IP has a "Green Tag" on it. The IP was replaced under warranty shortly before I bought it (probably 65k-75k miles ago). Maybe I'm lucky to get that many miles on the IP. I forgot what the "Green Tag" means but I thought it was a "good thing".

I already have a JK mild performance chip on it ( bought it several years ago) and may have the receipt or paperwork on it (that's a BIG maybe). I may still have the original chip (another BIG maybe). I planned on doing the gauges shortly after doing the chip upgrade but caring for elderly parents and not doing any towing have kept the performance demands to a minimum.

How do I determine if I have the 5068 IP?

Thanks for all the great suggestions!

[JohnC]

I'm going way out on a limb here. The reason for the huge plume of black smoke is that the PMD is shorted and the pump is going to full throttle. The reason it won't keep running is the PMD is shorted and the PCM can't control it. YMMV.

[Bruce_De_Mille]

I'm going way out on a limb here. The reason for the huge plume of black smoke is that the PMD is shorted and the pump is going to full throttle. The reason it won't keep running is the PMD is shorted and the PCM can't control it. YMMV.

JohnC,
I don't want you falling off a limb , but are you saying that the problem could actually just be the PMD and/or the extension harness?? That's the best news I've had all day if that is what you are saying! I'm still waiting for the Injector installation kit from Texas to get here. I need to get a new set of Injectors in there anyway and I'm sure the new set of GP's I already put in won't hurt either.
Thanks!
Bruce

[JohnC]

Yeah, that's my guess. My recommendation is to not change a lot of things that aren't likely cures to reduce the number of variables. That way you won't wonder if the no start is the PMD or just air in the lines going to the new injectors.

[Bruce_De_Mille]

Thanks JohnC,
I read your post after I power washed and just before I was ready to start on the injectors this morning. I've cleaned all the Neg grounds, battery terminals, and put in a new PMD minus the extension harness. Tomorrow We'll put the turbo back on and see if it will start up.

I broke the vacuum line (the formed plastic line was very brittle and it just broke). The local GM dealer has a vacuum harness/line for a 1999 but not the 1994 It appears that the only difference is how it routes around the front of the intake instead of behind it.

Questions:
1) Will the newer style vacuum line work on a 1994 6.5TD "F" engine ??
2) Will a broken vacuum line stop the engine from starting. I don't think it should affect the start (???) (I can wait for the new vac harness to arrive if I have to).
Thanks!

[Bruce_De_Mille]

RESULTS!
I just got it to run! I'm not sure exactly what fixed the problem since I did a lot of things (new glow plugs, new fuel filter, new PMD, fixed the stuck wastegate on the turbo, cleaned up all the grounds to the body & to the block, cleaned all the battery terminals, etc, etc). The REALLY GOOD NEWS is that I don't have to R&R the Injection Pump!! I was mentally prepared to R&R the IP and gained the confidence after reading a lot of your posts. When I really do need a new IP, I definitely will do it myself instead of paying over $2000 like I just did on my 1999 6.5TD.

Next I'm going to R&R the Fuel Injectors before putting it back on the road. I hope I can get to the one on #8 ??!! Thanks for all the help I really appreciate it