99 GMC Sierra Classic (old body style)---What distributor do you suggest?

AuroraGirl

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Speaking of venting, the distributor does have that little screen in the bottom of it, and every time I look at that the screen is clean and no buildup on it. Wonder if moisture is coming up through that??
Service Information
2003 Chevrolet Astro - 2WD | Astro, Safari (VIN M/L) Service Manual | Document ID: 1589507 #03-06-04-041A: Poor Engine Performance-Misfire, Rough Idle, Stalls, Engine Cranks but Does Not Run, SES/Check Engine Light On, DTC P0300 Set (Inspect Distributor Ignition(DI) System Components, Replace as Necessary) - (Jan 28, 2005)
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Subject:poor Engine Performance - Misfire, Rough Idle, Stalls, Engine Cranks but Does Not Run, Service Engine Soon/Check Engine Light Illuminated, DTC P0300 Set (Inspect Distributor Ignition (DI) System Components and Replace As Necessary)


Models:
2001-2003 Chevrolet Astro, Blazer, Express, S-10
2001-2003 GMC Jimmy, Safari, Savana, Sonoma
2001 Oldsmobile Bravada


with 4.3L, 5.0L or 5.7L Gas Engine (VINs W, X, M, R -- RPOs L35, LU3, L30, L31)

This bulletin is being revised to delete a model and add information to subject and inspection of distributor vent screens. Please discard Corporate Bulletin Number 03-06-04-041 (Section 06 - Engine/Propulsion System).

Condition
Some customers may comment on poor engine performance and the Service Engine Soon/Check Engine light being illuminated. Upon investigation, the technician may find DTC P0300 set.

Cause
This condition may be due to high levels of internal corrosion in the distributor, causing misfire, rough idle, stall and Engine Cranks But Does Not Run. This corrosion is attributed to a lack of airflow internal to the cap caused by the vent screens being clogged with debris.

Correction
Remove the vent screens and inspect the internal components of the Distributor Ignition System using the procedure listed below. If the distributor base has to be replaced, the vent screens will also have to be removed on the new distributor. If there is evidence of this internal corrosion, replace the affected component. Refer to the appropriate procedure in the Engine Controls sub-section of the applicable Service Manual.
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Important: All of these inspections can be done on-vehicle.


  1. 1. Inspect the distributor cap. You may notice a white residue on the cap walls. For higher mileage occurrences, the interior of the cap may have changed to medium brown in color
  2. 2. Inspect the distributor rotor. You may notice the presence of black streaks on the plastic surface. More typical evidence would be visible green spots on the copper surface of the rotor segment.
  3. 3. Inspect the distributor base. You may notice high levels of surface rust on the distributor shaft or surface contamination on the sensor hold down screws.
  4. 4. Inspect the distributor vent screens (1). If the vent screens are present, remove them by using a plastic-handled, long blade awl or pick (2). Insert into the airflow vent screens and pop them out. Refer to the figure for removal procedure. If the vent screens have been removed from the base of the distributor, then check the airflow inlets for being clogged with debris.
Parts Information
Part Number

Description

10452458
Cap, Distributor (V6)

10452457
Rotor, Distributor (V6 and V8)


93441559
Distributor (V6)

10452459
Cap, Distributor (V8)

93441558
Distributor (V8)


Parts are currently available from GMSPO.

To my knowledge 96 and up can use the same distributor, meaning if yours doesnt have both vents or has issues, you can buy the updated one.
 

OldBlueDually

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Thanks @AuroraGirl I have seen that bulletin. I personally do not see how clean screens in a distributor can cause any of those issues as mine have never been clogged up each time I check them. I have also used the good caps with the brass in them and end up with the same problem.
 

OldBlueDually

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I had similar problems with my K20. Sometimes would lose spark altogether. I found that power wire that plugs into the dizzy was worn out and loose. I cleaned it up and there was improvement... for a while. I didn't have another plug... which is strange because I have several old dizzys ... so I took the plug apart, cleaned of the oxidized metal and 'stretched' the tang to make a better connection. I ended up jamming a little tiny piece of felt to go under the 'tang' inside the plug. Now I had a tight fit! Zoom truck has been running without this issue for a few years since I did that.
So if the power connection to the dizzy is even slightly compromised there will be intermittent issues I am sure.

So how did you stretch the tang? Are you talking about the cam position sensor that is held into the distributor by 2 little screws? Even with that unplugged (or bad sensor) the engine will still run, but will throw a code and check engine light. Had this happen on my 7.4 Vortec in another vehicle.

I text a friend yesterday about this problem and he mentioned connections also but he said to check connections at the coil for the same reasons you just stated.

I just find it strange how yesterday it ran fine when on the test run with it, parked for an hour and when I started it this misfire was happening again....I just don't get it. I should go start it now and take it for another spin and see if it is still doing it, it is -2 outside right now :confused:
 

AuroraGirl

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Thanks @AuroraGirl I have seen that bulletin. I personally do not see how clean screens in a distributor can cause any of those issues as mine have never been clogged up each time I check them. I have also used the good caps with the brass in them and end up with the same problem.
PCV Issues, distributor issues, is the magnet thing working properl
internal wear

check the OE pn and whats your secoondary resistance reading on the coil
 

shiftpro

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So how did you stretch the tang? Are you talking about the cam position sensor that is held into the distributor by 2 little screws? Even with that unplugged (or bad sensor) the engine will still run, but will throw a code and check engine light. Had this happen on my 7.4 Vortec in another vehicle.

I text a friend yesterday about this problem and he mentioned connections also but he said to check connections at the coil for the same reasons you just stated.

I just find it strange how yesterday it ran fine when on the test run with it, parked for an hour and when I started it this misfire was happening again....I just don't get it. I should go start it now and take it for another spin and see if it is still doing it, it is -2 outside right now :confused:

No it's the power wire from the ignition.
 

SirRobyn0

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I know I'm about a month late to the party but maybe someone will find this useful. Back in the early 2000's I worked at a shop that had a contract to service a company with 100's of Astro vans. We weren't the only shop doing work for them but we were closest to their "van yard" No kidding they had so many Astro vans they bought a lot to park the extras. Same distributor setup as the V8. You have to use A/C Delco cap and rotor, if you still have this problem replace the distributor with a A/C delco unit. For some reason the aftermarket can't seem to make a decent, cap, rotor or distributor for these things. And while your at it A/C delco plugs and wires, a high resistance plug or wire even if firing ok can damage the cap on those rigs. That's not to say the other problems mentioned by other folks aren't your problem. I'm just mentioning what I saw over and over again and wanted to pass it on.
 

yevgenievich

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One thing will add to this thread. The rotor it self can spin and will cause poor running or no run condition. had to press back one in the right spot before.
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bucket

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One thing will add to this thread. The rotor it self can spin and will cause poor running or no run condition. had to press back one in the right spot before.
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That's good to know. I had no idea that was even possible.
 

SirRobyn0

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One thing will add to this thread. The rotor it self can spin and will cause poor running or no run condition. had to press back one in the right spot before.
In all the Astro vans I worked on I never saw that happen either / at least not that I ever tuned in on, like I said if we did a cap & rotor and still had issues, it was automatic distributor replacement, but we had the tools and were quite good and quick at setting the cam / crank correlation sync. In my 99 Class C with the 454 I carry a spare cap & rotor but not a distributor. I think I might go in there and scribe a mark. I try to be prepared for when we go far out.
 

OldBlueDually

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So, the problem with the truck so far has been resolved!!! (Issue being misfire/popping/backfiring/no power/jerking).

I put in this new distributor from Amazon due to the aluminum body, and the good reviews;
https://www.amazon.com/dp/B0761SV1BK/

The truck unfortunately still acted up (still had junkyard coil on it), and so I decided to also purchase a new coil for it. After the new coil was installed the problem went away. Dad came over with his scan tool, and verified all was running well so he cleared the codes and I took it for a spin with the scan tool still plugged in, she ran like a champ. He reviewed the scan tool when I got back and all was still good with no misfires or anything.

So, long story short I think I had another bad coil from the junkyard. I'm still glad I put on the new distributor however, one less thing to worry about.
 

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