97 Blazer dist question.

My neighbor just picked up a 97 blazer. He changed the intake gasket and couldn't get the dist set right. I looked at it, and when set to TDC it runs very well, but when you gun it quickly it will hesitate and sometimes a very small backfire, then will take off like normal. If you retard the dist setting 1 tooth it won't run. If you advance it 1 tooth it has no hesitation, but is hard to start when warm, and if started when warm will trip the CEL with a P1345, cam to crank position correlation fault. Is there anything else to look for with the hesitation? I told him to set it by the book for now and I will see what I can come up with. With it set right, it throws no codes and runs well, just has the hesitation and sometimes a very small backfire. With it set a tooth advanced, it runs well, no hesitation, but when started warm with throw a code. I have no history on this car and have never heard it run before he got it, so I have no idea.

It needs to be set on a engine capable scanner that will read camshaft retard setting.
Move the dist as close to 0 degrees - or + as you can get it.
Good Luck

When the distributor is aligned correctly, the P1345 will not be set.

Here's how to align the distributor: http://files.automotiveforums.com/gallery/showphoto.php?photo=51302
Or as MT mentioned, set it with a scan tool. When you have it set correctly, post back with details of how the engine runs and we can help you diagnose the rest.

Note:

It needs to be set on a engine capable scanner that will read camshaft retard setting.
Move the dist as close to 0 degrees - or + as you can get it.
Good Luck
With the dist set correctly it gets a very small backfire only when you stomp on it both in neutral and in gear. I have access to a Snap On MT2500, what am I looking for as far as cam setting?

When the distributor is aligned correctly, the P1345 will not be set.

Yep, I stated that in my orig question. I have no problems setting the dist, I am looking to know why it runs better when its not set properly.

Thanks to replies so far.

With the dist set correctly it gets a very small backfire only when you stomp on it both in neutral and in gear. I have access to a Snap On MT2500, what am I looking for as far as cam setting?


Yep, I stated that in my orig question. I have no problems setting the dist, I am looking to know why it runs better when its not set properly.

Thanks to replies so far.

If the scanner has the engine spefic cartiage.
You will see the camshaft retard setting in the data readings.
It may be in the missfire data or sensor data.
Look around in all data readings.
Good luck

Have you checked fuel pressure and leakdown? Low fuel pressure can cause hard starting, misfire, hesitation, backfire, induction and the list goes on....
Key on, engine off, fuel pump running: fuel pressure must be 60psi to 66psi. After the fuel pump shuts off, fuel pressure must remain above 55psi for 3 to 5 minutes.

I got a hold of the scantool and talked to him today. He said he might have time to bring it over tomorrow, so if he has time I will see what it reads and post results.

Fuel pressure is good and up to specs, as is leak down. Just curious, but how would fuel pressure have anything to do with it running better with the dist advanced a tooth?

As I said, I have no history on the car and he just bought it. I told him to post on this site, but he is an older guy not to familiar with computers, and he does not speak english very well, so he asked me to help out.

Clarify something for me: You mentioned "backfire", a backfire occurs in the exhaust. A "backfire" through the intake is called induction. Two different symptoms, completely different diagnosis procedures. Which are you experiencing?

There may be a vacuum leak, (internal or external) with the intake gasket, or possibly a leak in the air inlet between the MAF and the throttle body. Either scenario will cause a lean condition which can cause induction. Depending on where and how large the leak is, it may or may not set a DTC. The OBDII system does not monitor secondary ignition, fuel delivery, or base engine mechanical problems.

Clarify something for me: You mentioned "backfire", a backfire occurs in the exhaust. A "backfire" through the intake is called induction.
This may be, I am not here to get into a pissing contest with anyone over it. I am just looking to help a friend. That being said, you may wish to contact the writers of Mitchel on Demand, they have it listed as a backfire through intake.


Two different symptoms, completely different diagnosis procedures. Which are you experiencing?
There may be a vacuum leak, (internal or external) with the intake gasket, or possibly a leak in the air inlet between the MAF and the throttle body. Either scenario will cause a lean condition which can cause induction. Depending on where and how large the leak is, it may or may not set a DTC. The OBDII system does not monitor secondary ignition, fuel delivery, or base engine mechanical problems.

I do not know where it is happening since the one time it has happened in my presence I was inside the cab and did not hear it, just felt the hesitation. He told me it backfired. The car is not here and he has not brought it over today, yet. When it was here I checked compression, plugs, wires, cap, rotor, fuel pressure, etc. I did find the vac line to the vac ball on the hood was deteriorated off and just laying there, so I cut it down an inch or so to where it was still good and re-attached it. If he shows up today I will just replace the lines, or have him replace them and see if that helps any. Thanks for the heads up on this.


For either/both of you, or anyone else who may have input.
The shop I am borrowing the MT2500 scan tool from has just bought a Modus, since support is about to be dropped for the 2500. He offered the 2500 to me for $550 with all he has for it. What would I be looking for as far as cartridges, keys and software version? A brief history on myself is I have not worked for a shop for 18 years and have not been ASE certified for 16. I typically do nothing major other then help out people who ask. The newest car I have touched recently is a 2005, and that was just a wheel bearing. Is the brick worth it? I have seen the Solus going for as low as $850. Would it be better to scrape up the extra cash and hold off for a deal like this? just looking for opinions. Thanks to all who reply.

Duke350
I have used the red brick for over 20 years but had to go to a Solas pro for newer cars and trucks.
On the MT-2500 by it self it is not worth much.
But they will read OBD11 on up to can systems
If it has a later 3 in 1 import /domestic /obd11 cartiage there is where the money is.
Cost on them new was around 1000-1200 usa $
04 or 05 catiage still has a lot of use in it for up to 04-05 cars and trucks.
Even can system with the can adapter up to 04-05
But They quit updating or supporting all cartiages to it in past 04-05.

If the MT-2500 does not have the late cartiages and you are going to work on newer ones you might as well get the solas or solas pro scanner.
But always make sure it is updated.
You newest updates can run 1000 -2000 dollars and e bay can not do it.
Good luck

Going from a MT-2500 to a Solas pro is like going from a 10 year old PC to the lastest best bigest PC.

He finally came back today. He told me he replaced the vac lines but the hesitation was still there, so he put in some good name brand detergent fuel and a bottle of injector cleaner, and it went away, over about a weeks time. I would be willing to bet he just had some bad fuel, or some water in it.

I do have a generic scanner, an autoXray 6000. It works for the basics for now, so I think I will hold off until I can comfortably afford a Solus, or find a great deal on a Modus. Thanks for the help.

You are welcome and.
Thanks for posting back how it went.
Glad it is doing good.
Good Luck on finding a Solas/Modus.
Good scanners.

my heater core went out. and i would like to know how do i change it?i went and got the part

Start your own thread - this is about a '97 Blazer distributor.

You'll get more help that way.

Also, if you look in How To/Technical Info, you'll find a thread that details what you need to do, step-by-step.

my heater core went out. and i would like to know how do i change it?i went and got the part


Welcome to AF.
Best to start your own Thread/post.

Look for the New Thread button and give all info on your car/truck and someonne will help you.
Good Luck