95 wont fire

[Newbie600rr]

I know this has been covered before, but I have tried everything in the search. My 95 blazer 4x4 wont run, not even a sputter. I had to replace the spider assemply and gaskets under the lower manifold and now that it is togher I get nothing. I am getting spark and fuel and I have tried every timing combination possible. I have replaced the rotor, cap, wires, plugs, coil, and tested the ignition module. I can smell fuel. I have even pulled a couple poppet valves and they are pumping out fuel. I also have good pressure. I am not getting any codes and have good compression. No blown fuses and I can not even get anything with starting fluid. Im a little confused why it wont start so any ideas to point me in any direction would be appreciated.


Thanks

Chris

[muddog321]

Crank sensor down under the front of engine about $60 that tells the computer when to fire would be my next try. Dealer has scan tool to pinpoint but with a tow and $80-90 and hour.... your call. The cam sensor will not stop it from starting only screws idle up. You also have a MAP sensor so anyone help out on that one (I have all 98up and never dealt with that one).

[Rick Norwood]

Where did you have the ignition module tested? If it is the type that is inside of the distributor at the bottom, my 93 was just like it. I had it tested at Autozone and it checked good, but when it got hot, it would crap out. The point is I have seen them test good but they're not.

What did you mean by saying you've tried every timing combination possible? Explain please.

[DelCoch]

Was it running before you replaced the spider assembly?? Do you have spark plug wires that come out the side of the dist cap or out the top?? Have you tested the fuel pressure??

[BlazerLT]

If you smell fuel you probably didn't replace the nut kit that feeds the fuel to the injector.

They will leak and therefore the truck will not start.

Smell your oil dipstick, I bet you it smells of gas.

The gas getting into the oil will ruin your engine.

Also, did you test the fuel pressure or are you just assuming it is fine?

[Newbie600rr]

It did run before I took it apart. I did replace the nut kit and fuel pressure was I believe in the upper 50s. I cant remember off- hand but I remember it was wat the book said. The plug wires come out the side and the ignition module is the kind by the coil pack.


Thanks Again

Chris

[DelCoch]

Ok, you've got the same engine I have in my "95. Actually, what you are calling an ignition module, GM calls Coil Driver. (mounts of the back side of the coil)

Need to know where you're testing the spark at? It should be tested at the end of a spark plug wire? If so, what does the spark look like? It should be bluish white, if orange or yellow, probably not a strong enough spark.

Initial fuel pressure when the pump is first activated must be 61 to 63 or it won't fire the injectors, and when the pump shuts off it should hold a pressure of 57 to 59.

There is no timing adjustment on this engine. My GM shop manual says turning the distributer will have no effect in changing the timing.

If the distributor has been pulled then you need to get #1 piston up on the compression stroke, align the timing marks to TDC and re-install the distributer with the rotor pointing to #1 cylinder.

P.S. You said starting fluid does nothing, in which case I would say the spark plugs are not firing. If the plugs were firing and you spray starting fluid into the intake it should fire, backfire, run backwards, or do something, even if out of time.

[BlazerLT]

Actually, the ignition module he is thinking about is the one on the back under the distributor cap.

They sometimes will fail.

[DelCoch]

Does your coil mount on the passenger side of the engine and look like the below picture?

If so you won't have an ignition module inside or attached anywhere to the distributor.



I doubt it will have a pickup coil inside the distributor either.

.

[Newbie600rr]

the pic is exactly what I have. I tested the spark at the end of the wire. I took a plug and grounded it out on the engine. It had a blue/white spark. This is why it is so troubling, It seems to have everything it needs but it will not run. Thanks again for everybodys help.

[muddog321]

95 - that has a dist that must set timing as I recall. 96up is set. Who has a 95 and knows timing exectly??? The ign module is inside the dist on a 95 under the rotor. 96up is on a heat sink mounted as part of the coil mount (just did my 99). Check the firing order on the plug wires. When was the cap new - just put in or awhile ago - just had a bad cap and no way to tell without replacing as it acrs inside (in the casting) of the plastic runs to the wires.

[DelCoch]

Originally Posted by muddog321

95 - that has a dist that must set timing as I recall. 96up is set. Who has a 95 and knows timing exectly??? The ign module is inside the dist on a 95 under the rotor. 96up is on a heat sink mounted as part of the coil mount . . .

Some '95s have the same set up as the '96. He just said his is the same as in the above photo, which is "heat sink mounted as part of the coil mount". (See above photo) With this ign system there is nothing inside or outside the distributor cap as far as an ign module. You can not change the timing by turning the distributor on this type of ign system.

Newbie600rr,

It might be worth your while to check the spark on all the plugs, as you could have good spark on one and bad on the rest. The auto parts stores sell a spark gap checker for less than 10 bucks that allows you to clearly see the spark and how far it will jump. If it's not a spark problem then it has to be a fuel related problem. Be sure to re-test the fuel pressure, as the fuel regulator may have gone bad. The only other thing is to get a fuel injector tester to see if the fuel injector is firing.

I would have to say since it was running before you did the repairs the no start problem must be related to something you did or didn't do while making the repairs. Make sure everything that was disconnected during the repair has been reconnected, like the crankshaft sensor, etc. You may want to take the upper intake off again and check to see if everything is in order.