Possible buy / OBD code question

[RJNH]

Like typical, there's that one thing... This one doesn't start. Owner claims it's just a distributor swap out. Can I prove this without changing the distributor myself.

It's a 2001 GMC 5 window 5.7l gasser with 60K miles on it. A private school bus used mostly of events/outings. Service records available for viewing.

2001 makes this OBDII compliant. What codes am I looking for to prove this? What else should I be looking for as codes go? As in typical non-start situations. Distributor has the EGR, so I figure this could be some sort of vacuum leak as well.

I figure to talk more about symptoms when I can go and see it. For now hoping to hookup my OBD reader and check codes..

[Mountain Gnome]

distributors don't have EGRs. Exhaust Gas Recirculation has nothing to do with firing a spark.


I also would not be surprised if this is a distributorless ignition, but a few minutes of poking around google doesn't give me answers.


Remember when Google was an awesome search engine? Now it is just a lame advertising platform.

[Mountain Gnome]

Also, if this is a van cutout, it will likely have an OBD-II port. If it is built on a full/mid-size chassis, it may have the J1939 (I think) port.


Pull the codes if you can and see what it says!

[CHEESE_WAGON]

I've never seen a 350 with factory coil-on-plug ignition (DIS). Not saying it's impossible, but I've never seen one.

The 2001 350 would be a Vortec, hence it should have a flat-top dizzy with horizontal wire terminals. They are also very picky about fuel pressure, like a diesel.

Common issues on this style 350...

Intake gasket failure
Fuel injector spider leaks
Fuel pump failure
Distributor housing cracks

If I were a betting man, I'd say the problem is the injector spider or the fuel pump. The usual suspects and all that. They are the most common failure on these. The dizzy on this engine also has a plastic housing that is known to crack and leak oil inside the cap, which can fry the ignition module. The dizzy drive gear is also made of plastic on some and has been known to be a problem.

In this thread, I discuss these issues and others that are pertinent to that thread's OP's situation. Could also be a bad coil, it is usually mounted near the dizzy at the rear of the engine.

[Mountain Gnome]

Originally Posted by CHEESE_WAGON

I've never seen a 350 with factory coil-on-plug ignition (DIS). Not saying it's impossible, but I've never seen one.

I would think it would have gotten a solid-state ignition module by 2001 (not coil-overs - I see those POS systems in Fords). but I have never seen this motor. Google says it went into a Corvette and Holset Custom Vehicles (or something like that). But I did see plenty of ads for spinning old-school distributors for this engine, but they all said earlier than 2001.

[Danjo]

If it’s got an ODBII port, usually just under the drivers dash, around knee-level it’s a good idea to plug in. Most readers have LED lights or other means of showing condition other than codes. It can, for instance, tell you if the codes have been cleared. If they have been, then you’d either need to get the owner to put some miles on it to get the computer to either register all is OK or to throw codes.

[CHEESE_WAGON]

Originally Posted by Mountain Gnome

I would think it would have gotten a solid-state ignition module by 2001 (not coil-overs - I see those POS systems in Fords). but I have never seen this motor. Google says it went into a Corvette and Holset Custom Vehicles (or something like that). But I did see plenty of ads for spinning old-school distributors for this engine, but they all said earlier than 2001.

They were all solid state from the mid-70s. HEI is technically solid-state, as they have electronic modules. What I believe you're thinking about is module-mounted coil packs that still use ignition wires, like the sidewinder 4s and 6s, but the LT-style Vortec engines never got it. Here is a link to a dizzy for an '01 Express van with the 5.7... More or less the same model. The 5.7 never got factory coil-on-plug because for '02-'03, it was being phased out for the LS which was designed with it from the word go.

Originally Posted by Danjo

If it’s got an ODBII port, usually just under the drivers dash, around knee-level it’s a good idea to plug in. Most readers have LED lights or other means of showing condition other than codes. It can, for instance, tell you if the codes have been cleared. If they have been, then you’d either need to get the owner to put some miles on it to get the computer to either register all is OK or to throw codes.

A bad fuel pump will likely throw no codes. A leaking injector spider might throw sporadic codes for random / cylinder misfire, or rich mixture.

It's simple enough to use remove a plug and use insulated pliers to hold it to the cylinder head to see if it's sparking. It's also simple enough to see if the fuel system holds a constant 58-60 psi without re-priming.

No spark, bad dizzy or module (cam sensor code confirms this, it is in the dizzy). Fuel pressure below 58-60, fuel pump or spider, possibly fuel pump control circuit problem. It's common enough they package new pumps with replacement pigtails.

[Mountain Gnome]

No, I meant the big black box thing with a wiring harness connection to the ECM, and all the spark plug wires attached to it. No moving parts. It was under the impression it does not usually go bad.


I think of a "distributor" as something that moves (spins) and distributes a high-voltage current from one coil to multiple plugs, depending on its position of rotation.


The big black box thing I think has multiple coils inside, like coil-overs - each plug gets its own, but all in one package.


Maybe I'm wrong.

[CHEESE_WAGON]

Originally Posted by Mountain Gnome

No, I meant the big black box thing with a wiring harness connection to the ECM, and all the spark plug wires attached to it. No moving parts. It was under the impression it does not usually go bad.

Yeah, like this?

That is what I thought you were talking about. Order of the day for 87-up front drive 4s and 6s, but not for rear-drivers. The RWD turbo Buick 3.8s of 1984-1987 started this, more or less, but it was the only RWD I'm aware of that got it. It was adapted to the FWD 3.0 / 3.8 / 3300 / 3800, and the 60-degree 2.8 / 3.1 / 3.4. Though technically there are moving parts, the crank sensor that reads a reluctor in the harmonic balancer, and a flying magnet on the camshaft sprocket read by a camshaft sensor.

[Mountain Gnome]

You sure are a plethora of "trivia".

[CHEESE_WAGON]

Originally Posted by Mountain Gnome

You sure are a plethora of "trivia".

Just a lot of experience, a lot of wrenching, a lot of reading, a lot of researching theoretical projects, and a lot of poking around salvage yards. As Richard Pryor said, "You don't get to be old, being a fool." At the tender age of 45, I'm starting to get it. I feel like I'm 90. Which is why my centrifigual-supercharged RWD 3.8 Buick-powered GNX clone will never be a reality...

[Mountain Gnome]

Ah, the salvage yards! You can learn a lot there!

[mokibrabrant]

Well if I'm ever in the market for one of these imposters now called buses that are vans without bread printed on the side I will come to you CheeseWagon.
You have my sincere sympathy for having absorbed so much reference at so young an age. Right on though. Respect.

Amazingly I do look at these things in occasion. And I am amazed at the mileage these 6.8's can accrue. Yeah I know you're an hour's guy. But I'm a actual miles guy. Un less it's a two stroke. Then I want to know how many hours they sat their at low idle screwing up the cylinder walls and injectors. And Ford fuel pumps...??? God spare me.. and their distributers that skip time...kill me. I have one Ford Van. All mechanical. Never failed me. But these ECM mounted beauties will always fail. It's always a matter of when. Beyond my expertise. OBDjuancannobe.
I mean for the love of all that's Holy. Could I ever pridefully hold my head up. Walk into a parts store and ask for a 2001 Dizzy.....

[RJNH]

Thanks folks!

CW, you are on point with the 'Dizzy' and I suspect the present owner is guessing at what's wrong. Hope to learn much more once I see it.

The statement of EGR on Distributor comes from the owner and again why I believe they are guessing as it may be possible of it mounting near/on, yet doubt on. Again, to be seen.

My thoughts are much on the same line of possible issues you speak of. Most being fairly simple to swap out. All being something I can do in my shop.

I'm now awaiting a return response for a proposed viewing.

[RJNH]

If nothing else, I'm leaning from each experience. To that I say thank you all!

The owner responded, I ask a couple additional questions, he responded with it's sold. Guess I asked too many questions... Personally, not feeling a loss here.

I congratulated him on the sale and wished him the best.

Next.....

[Jolly Roger bus 223]

Originally Posted by RJNH

Like typical, there's that one thing... This one doesn't start. Owner claims it's just a distributor swap out. Can I prove this without changing the distributor myself.

It's a 2001 GMC 5 window 5.7l gasser with 60K miles on it. A private school bus used mostly of events/outings. Service records available for viewing.

2001 makes this OBDII compliant. What codes am I looking for to prove this? What else should I be looking for as codes go? As in typical non-start situations. Distributor has the EGR, so I figure this could be some sort of vacuum leak as well.

I figure to talk more about symptoms when I can go and see it. For now hoping to hookup my OBD reader and check codes..

that bus does not have a distributor is has coil packs.
the PCM controls timing and spark with the ICD/ICM ignition control module.
google obd 2 codes for a gmc savanah 2500 for trrouble code.
i will look at my 2004 when manual when i can get my hands on it.

[Jolly Roger bus 223]

ok
the ignition trouble codes are
P0351- ignition control circuit out of range
0351 is also circuit/plug one and so on through through 0358 being ignition coil 8 control circuit.
0315 through 0343 are knock sensor crank and camp position sensor faults.

P0301 through 0308 are engine misfire detected cylinder corresponding like 0308 is cylinder 8
0200 is fuel injector control voltage and 0201 through 0208 or specific cylinder injector.
0400 codes are fuel system related.
0500 are a mix and the only ones that might create a no start are 0500 through 0563.
0600 are all PCM related codes. and a few transmission TCM in the 0667 through 0669
0685 is specific to ENGINE CONTROLS IGNITION RELAY CONTROL CIRCUIT.
O700 CODES ARE TRANSMISSION SPECIFIC
p 0850 is is park/neutral switch
and 0900 numbers are transmission shift solenoids.
i love my wifes shorty with the 6.0
but would think the 5.7 would be a little sluggish unless beefed up a little.
hope this helps

[MilesOriginal]

It it's just a swap out, why haven't they done it?

[CHEESE_WAGON]

Originally Posted by MilesOriginal

It it's just a swap out, why haven't they done it?

Some people are just that lazy. Just so happens these Vortec dizzys have a camshaft sensor in them and must be positioned precisely or the PCM will throw a code no matter how well it runs. Besides, it already sold, OP updated earlier.

[Bluthebus00]

Originally Posted by CHEESE_WAGON

Just a lot of experience, a lot of wrenching, a lot of reading, a lot of researching theoretical projects, and a lot of poking around salvage yards. As Richard Pryor said, "You don't get to be old, being a fool." At the tender age of 45, I'm starting to get it. I feel like I'm 90. Which is why my centrifigual-supercharged RWD 3.8 Buick-powered GNX clone will never be a reality...

Mmmmmmm a GNX would be lovely!
Best of luck!!
Edit: https://classiccars.com/listings/vie...-florida-33312
i haven't come across any centrifug-supercharged modded ones though. Might be a fun project for ya