More issues with my truck!!!!!

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dirtrider73068

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Good grief what is it with me and my truck, I got my tranny fixed had to rebuild it, the last shop didn't do it right the last time,

now for some reason its burning oil, this motor is a crate from autozone has about 30k miles on it, I get off work one day start it up and it blows smoke like crazy!!! And its oil cause you can smell it and see the blue smoke. I get home with it, look at the little stuff, PVC is fine and working like it should. Was told might be intake gasket, so I had a set laying around since I had the wrong ones in it from the begining, so take it off and find the four middle bolts were pretty loose, take it all off and can see on the heads were oil was getting by, and oil in the intake ports. Clean everything up put it all back together, got all bolts torqued down like they should and in steps, fire it up and it purrs runs real good. Let it get hot check the torque again everything is ok.

So I take it down the road smokes a little figure its burning off the leftover oil, get down the road, slow down to make a turn and it clatters and blows a plethera of white, gray, black smoke. I am like WTF is it now, come back home check things out everything is in order. I did forget to hook up my MAP sensor when I first started it, it did set a code, so I thought ok maybe need to reset the ECM and clear the codes. Pull the positive on the batt wait a bit hook it back up, and now it runs like ****, rough idle erratic, barley runs in gear. Shut it off, by this time am pissed. Let it cool off, come out next day, pull plugs and they are black crusted, threads are covered in oil. Timeing is right its been checked, PVC is working there is pressure in the crankcase like it should.

I have checked everything I know that could be wrong, even put new fresh plugs, runs rought still, took it to my uncle thats a tech has been for years, don't live far form me just a few blocks, and its fouled the plugs again, black crusted.

But I pulled all plugs again adn 2 of them are still good all the rest are black. I a did compression test and this is result cylinder 1,3-92 cylinder 5,7,2,4-95 cylinder 6-120 cylinder 8-119. I am also wondering if I may have a flat cam to why its running rough, but son't explain the burning of oil and black plugs which could be rich.

Its a 94 chevy 350 TBI, any ideas out there of what to check, other than short of pulling valve covers and watching the valves move to check cam is flat, looks like another rebuild.
 
Compression is low and erratic, cylinder-to-cylinder.
Do a leakdown test to check rings.

Won't explain the sudden oil consumption problem, though. I'd look at the intake gaskets again. Might have a cracked head/intake, blown head gasket(s), slipped intake gasket, etc.
You didn't say if all of the plugs are equally crusty and oil soaked or just a couple. That will help to determine if you have individual cylinder problems or an intake misconjammeration.
(Tip: Do NOT put RTV on intake gaskets, only on end rails and corners.)

Are you sure it's a flat tappet cam? Might be a roller. I've had a few late model SBC's but can't remember which ones got the roller ('97-99 Vortec maybe?? dunno). I have a good stock roller cam, spider and timing set (no lifters though) out of a very low hour boat engine for sale cheap if needed.
 
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did you pull the codes and see what it was saying?? You gotta jump the terminals to read them. Google it. I use a paperclip to jump the terminals. Also with that low of compression on that new of an engine I would think something is wrong with the valvetrain.
 
Well the 2 plugs that were in good shape was cylinder 2,4 all others were black crusted like they were fuel fouled or oil fouled. Before new plugs were put in all 8 were black either fuel or oil fouled and pretty much gone.

How do I go about doing a leak down test, and what does it exactly do? I know you pump air into the cylinder then watch a gauge. Could I not do this with a air nozzle and listen for hissing sounds anywhere to get a idea of what could be leaking or cracked or broke misplaced?

I did spray some carb cleaner around the intake when running testing for leaking and nothing happened.

Mine is a 94 but its a crate long block from autozone so doubt its got a roller cam in it.
 
warriorkid23 said:
did you pull the codes and see what it was saying?? You gotta jump the terminals to read them. Google it. I use a paperclip to jump the terminals.
Click to expand...

Yea pulled codes, one was the MAP sensor because I had forgot to put the vac line on and the tps circut, but once the map was connected it all went away. It says in the book that if codes are set it has perimeters it goes by and goes into default, clearing codes after issues are fixed puts the ECM back in program mode for that sensor. Even with it running rough no codes are being set.
 
Compression and leakdown testing :
http://www.aa1car.com/library/compression.htm
Note: need to check compression with all of the plugs out, also.

Need to determine if it's gas or oil fouling the plugs. Oil fouled looks wet and gooey like tar. Gas fouled generally looks fluffy and dry.

A leaky intake manifold (drawing oil) pulls the oil mist from the lifter galley. Spraying the manifold on the outside will only determine leakage up top, drawing clean air and causing a leanout. It can leak either way, or sometimes both. SBC's usually don't have this problem, but it can happen (dirty or warped gasket surfaces or the aforementioned overuse of RTV). I would not focus on this too much... I still don't think it's your problem.

If gas fouled, something could be wrong with the TBI system dumping too much fuel. If so, you would have noticed a fairly large drop in gas mileage. Excess fuel can wash the oil off of the rings/cylinders, wearing them out and causing the low compression.
One problem feeding another.

Unfortunately, I'd bet you're in for another rebuild (due to toasted or stuck rings, and/or scored cylinders causing the low compression). With only 30K on it, my guess is the rings were not broken in properly and did not seat from the get-go. Best case scenario is the valves are not seating (carbon buildup on the seats) causing the low compression.

Gotta determine if oil or fuel fouled plugs so you're not barking up the wrong tree...
 
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The plugs aren't gooey or tar looking, just a flat black crusty looking plug, so that would mean gas fouled, but it still will puff blue smoke if you goose it.

The rings not seating would make sense, but still don't explain the clatter and the billow of smoke after slowing down make a turn than get back into the throttle, and the rough running after cleaning codes. I plan on still pull valve covers and see if all that is working order just so I can rule out everything that I checked. Could I just use my air nozzle blow air into each cylinder at TDC to see if adn what is wrong with it, or would I need to find a leakdown tester?
 
Nope, need a tester. All cylinders will "leak", the tester determines how much and where the leak potentially is (poorly seating valves or rings). Rough running could be the low compression cylinders not efficiently burning the mixture.

Define "clatter"?
Detonation?
I know when I mash the loud pedal on my stock '90 5.0 Mustang, it detonates (on 87 octane) and pours clinkers out of the exhaust like an old coal furnace. That's the detonation pounding the hell out of the pistons and connecting rod bearings (very dangerous condition). Usually an engine detonates either on
1) cheap gas, or
2) leanout (too much air) or
3) overheating
...and those symptoms usually show as a clean, white plug, not a fluffy fouled one. Sooooooo......

Those old (pre OBD-II) computer systems give only "general" codes, unlike the modern stuff that tells you all kinds of specific diagnostic stuff.
Without actually hearing or seeing the engine, it's really hard to pin it down for you.

I'd do the oil squirt test outlined in the link I posted as a start. Won't cost anything but time.
 
Well the clatter is like in the old days when you shut off a motor and it would diesel kinda kinda that clatter then the smoke. I wish I could make a video of it but don't know how to do that, so far from what i have tried tested some that I have talked to is running it down to a rich mixture for some weird stupid reason or something internal.

At this point I know its getting fire to all plugs check all parts with a spray of water and nothing pop or jumped fire but still could be grounding out somewhere I can't see. PVC is working crankcase is building pressure and not vacuum. Its not popping back into the intake so cam should be good. Know its getting fuel so all that is working. Its in time, unless its jumped time but it wouldn't run if that happened since it fires at 0 degrees TDC.

There is one thing I did find out tonight, if you power brake it, and run the throttle up at a certain point it starts to pop or backfire in the exhaust, that could be just from running rich, but still don't explain the roughness or burning oil. One thing I did think about is maybe the valves or valve spring could be sticking. The hard part is if there is a dead cylinder is find that dead cylinder and finding out why its dead.

This TBI is a basic bare bones fuel injection system nothing really to it, the ODB I is a basic computer port is has the basic sensor's it needs to run. Which none of those are bad since no codes are being set.

One thing I think might be a issue could be the ignition module in the distributer, I think autozone test those but I will need to take it out and take it to them. I did have issue's before with it shutting off while driving one time, and a hard start in the drive another time. If it comes back good that one thing I can mark off the list of things tested.
 
One thing I discovered last night after trying to see if its jumping fire and useing the timeing light to see how much fuel it was spraying out the injectors, I did a power brake, put it in gear and pushed on the throttle and at a certain point it would pop or backfire out the exhaust so I plan on pulling the valve covers and looking at all the valves to make sure they are working or if I thrown a push rod.
 
if its tbi injectors there are filters in the injectors that get cloged up you wont notice the injector spraying any less but you will feel it (missing ,backfiring ,no power)
10JECS.JPG
 
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Ok how hard is it to take those out and clean them off or replace them. I just took the valve covers off and all valves are moving fine they are all moving in unison. I might take the ignition module out and take it in to be tested just because. It did cough and backfire when I tried to start it once, it could be a vacuum leak somewhere, maybe the intake didn't get set right may take it off and do it again. Other than getting a leakdown test to get a real ruleing on what is going on I don't know what else to do.
 
Yea I looked the filters there like 2 bucks, then the gasket kit about 13 so thats something I am going to be looking at doing if thats not the problem then it can be checked off the list with the other stuff.
 
UNFREAKING real I got my truck going I think!!! And its something damn stupid I could shoot myself as a pretty good knowledge shadetree mech I should have known.

The break down, I figured it maybe the injectors so looked around they are 80 bucks a pop, no way am I dropping 180 buck for nothings. So I took my TBI off and all apart, cleaned it, used solvant tank at work, put everything new on it gaskets o-rings filters fuel preassure regulator. Put back on same thing runs rough but the fuel injectors flowed better and the pattern was better. So I said **** it. Walked away again, did a google on TBI's found a truck forum, joined and did some reading posted my issue, in the light of it another guy having running issue like mine, replaced his TPS, but no codes set and it worked, I thought maybe mine, naw can't be.

So I looked in the book at wire diagram traceing everything over to see what is tied where. Fixing to call a shop and have it worked on, I go out today for shits and giggles and look it, just staring and thinking, something or somebody or a ghost said "he look at those plug wires they are wrong" so I traced out the fire order and slap me stupid I had 2,4 crossed swapped them back and it ran great smoothed out, runs fine no smoke but a little think its just excess oil and fuel. Took for a drive no clatter and no blowing smoke.

God how stupid could I be and not check those freaking wire first. I should have know, I thought it was something simple and something with the ignition system, was getting ready to do a complete tune up, from cap to plugs to filters.

I plan on sucking some seafoam in her to clean out the soot and carbon form all this so maybe, say a prayer of hope I have my baby back and drive it now.
 
Yea but I am smart enough with this stuff I should have known to check it anyway, I know damn sure will next time will be first thing to check.
 
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