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Super Mechanic
Super Mechanic, Master technician
Category: Chevy
Satisfied Customers: 17220
Experience:  29 yrs. exp., ASE master, cert. in G.M. electrical, a/c, susspension, brakes, electronic steering
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I have a 97 chevy blazer that was running fine, I parked it

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I have a 97 chevy blazer that was running fine, I parked it overnight and went to start it, and it started but ran very rough. Now it won't start at all. I have 55psi fuel pressure. I replaced the spark plugs, distributor cap, plug wires, ignition switch, ignition coil, icm and fuel injectors. I'm getting spark and fuel, and the engine has God compression. But what would keep it from starting?

Hello and welcome. My name is ***** ***** you for visiting the site.


The Vortec engines are very picky about their fuel pressure and 55 PSI is low. Even with good fuel the pressure has to be at least 60 PSI to start the engine.


If you accept my additional service request for your email address, you can give me your email in a private info box and I'll send you the test instructions in a PDF file, the file is rather large.

You will just have to accept the additional service offer and ENTER your email address in the “ENTER CONTACT INFO” section so that I can see it, Thanks

Let me just say that any money that you paid, or if you have a subscription, that money stays in your account until the answers are rated, (positive) regardless of how fast or how long it may take to get finished. You can FOLLOW UP AT ANYTIME, even after rating.


Fuel pressure - 66 PSI. The Vortec engine is very touchy about the fuel pressure and when cleaning the systems we have to turn the machine up to 85 and sometimes 90.


Please don’t forget to rate the answer in a positive way, . EVEN IF YOU HAVE A SUBSCRIPTION ****THAT IS THE ONLY WAY I GET PAID **** Thanks

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Customer: replied 1 year ago.
Ok so I replaced the fuel pump with a delphi, and I have 65 psi now but still no start. I have spark and about 160 psi compression all the way around. I am fed up with this truck. I forgot to mention, that my transmission had no gears when it started with the running issue. They both stopped at the same time. Are there any parts that link both together and could be causing all my problems? Also if I spray starting fluid in the intake, it will not run.

I see, thanks. With the compression that good, I would not think that the timing chain is bad. The one thing that has stumped a few tech over the years is a clogged cat. You can see if it will start with the front pipe unhooked from the exhaust or sometimes take out the front 02 sensor as a test. The 3 things needed to run are spark, fuel and compression but also a way for the combustion to get out. Not anything with the trans though.

Customer: replied 1 year ago.
I actually already tried in hooking the exhaust at the flange. If it helps, my turn signals dont light up on the dash or outside the vehichle, only the top brake light works, and my hazards also don't work.

They did a lot of issues with the hazard and turn signal switches but it shouldn't stop the engine from running.


Is there spark to all of the cylinder, (plugs) and the spark plugs are not wet with the starting fluid? I have had at one time an engine rebuild that the new cap was bad and not sending the spark to the right cylinders on that type of setup. We had spark to all the cylinders but it was at the wrong time. Cap was made too thin on the insides, between the towers. I assume it didn't start with the old cap though.

Customer: replied 1 year ago.
There is spark to all the cylinders. And I tried another cap and rotor that was off another blazer and no start. The weird thing is, I had it running pretty good since the original problem. But it would not rev up, it would only hit about 3000 rpms. Then I let it run for a while, aND it just shut off and hasn't started since.

That is strange. Does seem to sound like the timing chain. Hard to say but they do have a test for the chain, we always would go by, over 10 degrees on the crankshaft pulley. How far you can go before the distributor rotor starts to turn. After going back and forth, of course. You make a mark on it at TDC and then turn, (by hand) the other way.


Check camshaft timing chain free play. If the camshaft timing chain can be moved back and forth in excess of 16 mm (0.625 inch) replace the timing chain.


Customer: replied 1 year ago.
Ok, question for ya. I have 3 relays under the hood, and I switched two of them and it would not crank. I switched out the known bad one and it cranked but still no start. What are those relays controlling and if two were bad, could that be my problem? Also I was wondering if my torque covert er lock solenoid going bad could cause a running issue, because the blazer when I had it running would drive forward in neutral and try to in park.

With the engine not running the converter even locked wouldn't have anything to do with starting, there would be not enough pressure in the trans hydraulics to reach a stall speed.


The relays with locations and what they are is in the attached diagram. One has to be the starter relay.


Customer: replied 1 year ago.
Hi again! Still no progress, tried another distributor and still no start. I did however figure out that I have no vacuum. I disconnected the hose coming from the intake, and no vacuum when cranking. My dad's 2001 blazer does have vacuum when cranking. I am assuming this is my problem but I don't know what would cause this. What would cause there to be no vacuum?

The only things that will cause no vacuum at all when cranking the engine would be very late valve timing or a clogged exhaust, (when the compression is good, of course) and if the chain was that bad the compression would be a lot lower, (under 100 psi).


I am out of ideas. I will opt out and open it back up. Please DON’T REPLY to this post as that will lock the question back to me, someone should be along shortly, I’m sure, thanks and sorry I wasn’t able to help with it.