My '99 blazer was bought with a new 4.3L motor, and new distributor, less than 2kmi on both. When it goes down the interstate it seems sluggish, and when it comes to a gradual hill it loses about 10mph, and it doesn't pull steadily, it feels uneven like it would feel if maybe the air filter was badly clogged or something, it pulls okay then it loses some power, then it pulls okay again, then feels like it loses power, intermittently.

Do these vehicles still have the pick-up coil in the distributor like older 4.3's have? It has the same symptoms my '94 Astro van had and I found the little coil in the distributor was badly deteriorated, and replacing it cured the issues immediately.

I have a new (I think) pick-up coil for the '94 motor sitting here, part number DR123 (It's a Duralast labeled box) it measures 783 ohms. Will this work in the '99 distributor or is there a different part for the '99?

Should I opt for an aftermarket distributor? Which one?

 

i'm not there too look it over but sounds more like fuel pressure problem or a cat plugging up to me

 

My 99 4.3 Blazer has an external coil.

 

Chevy rag top - your prob thinking ignition coil this is inside the the dist - Doug i'm pretty sure the 99 is a cps instead of the coil that wraps around the dist shaft

 

No it uses a crankshaft sensor in the timing cover and the PCM to trigger the ignition module which is mounted externally near the coil. All the distributor does is distribute the spark and give a cam sensor reading (cam sensor often confused for ignition module). Don't disturb the crankshaft sensor in the timing cover unless you want to pay to have a crankshaft sensor relearn done.

Your symptoms could be caused by a lot of things. Guessing isn't in order. If you want to diagnose, then you will need a capable scan tool of your own, some tools, and a desire to see things through logically. Performance problems are seldom easy. Let us know.

Capable scan tool here. $8 + $25 = $33 Won't do Crankshaft Sensor relearn. That would take at least $350 software like HP Tuners, EFI Live or Autoenginuity.

https://blazerforum.com/forum/2nd-ge...-retard-90496/

 

As mentioned, the sensor in the distributor is the camshaft position sensor and does not affect engine performance.

Is the check engine light on? Are there and trouble codes in memory?

Certainly could be a problem with fuel delivery. This link will help: https://blazerforum.com/forum/2nd-ge...eakdown-88305/ Post all 4 readings and we can help analyze them.

 

This is not related to or is about the crank sensor. There is a coil in a GM distributor that gets hot and breaks down when it gets old, the impedance of the coil changes and the vehicle basically runs but erratically and loses torque. You can have every diagnostic tool ever made attached to the vehicle and you driving it down the road reading all the screens, and NONE of them will tell you that this coil is the culprit.

In fact I did *exactly* as I described above once with my '94 Astro, guy at a dealership had $200k worth of tools in his bay, he has all the bells and whistles when it comes to scanners and computers, so we hooked all of it up, went for a drive, he could read throttle positiion, A/F ratio, ignition timing, shift points, air flow, air temp, he had every piece of vital engine info on the screen while driving. It was pretty cool actually but at the end of the drive? It stumped him and he had no suggestions as to what might be the problem.

I read something about this coil on the S10 forums and decided to replace mine. It cost $17 and when I got the distributor out and torn down, pieces of insulation were all over the place, and the coil had basically disintegrated. After I replaced it, the motor ran great, it didn't lose speed and downshift on a long hill, it pulled steadily and lost all that erratic pulling that it was doing. All for $17 bucks!

So I put this thread up asking does the '99 (Vortec motor, W vin code) distributor still have one of these coils. Apparently it uses a coil as well, but not one that encircles the distributor shaft. I may swap one in there just to SEE if it makes any difference.

 

No check engine lights, I will take it over to Advance and let them hook it up and see if there is anything in memory and post later.

 

1995 and older had HEI ignition using the pickup coil in the distributor. 1996 & newer have EDI ignition systems. They do not have a pick up coil in the distributor. The pick up coil was the trigger, (reference pulse) for ignition timing. The crankshaft position sensor now provides the pulse for ignition and injector timing.

 

And I told you NO it does not have one of these pick-up coils. My apparent mistake was trying to explain how it does work so you might have some understanding of the system. Good luck with the Autozone scanner/changing parts strategy! Not sure why you posted, it doesn't seem you are interested in listening. In any case, a waste of my time. I tried.

I challenge you to go buy a pick-up coil for your 99 Blazer. Good project for you and Autozone.