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98 S10 Blazer cranks but wont start

12-07-2006, 05:15 PM
Started fine yesterday. Died while idling. It now it cranks but wont start. Not sure where to start troubleshooting.

12-07-2006, 05:29 PM
check the coil, and check fuel pressure at the shrader valve.

my bet is the coil

12-07-2006, 06:18 PM
1) Check that you have at least 1/4 tank of gas.

2 ) Check the fuel pump maximum pressure at the schrader valve with a fuel pressure gauge. Be aware the fuel pump only runs for 2 seconds when you turn the key on (engine off). Then the key has to be off for 10 sec before the pump will run again.

With a properly working pump, the fuel pump reaches its max pressure during that 2-seconds, which should be something over 61 psi. When the pump shuts off the fuel pressure will immediately fall 5 or 8 psi. (This is normal) It should not fall below 50 PSI.

To see the max pressure put the gauge where you can see it when you turn the key on (engine off) or else get someone else to turn the key or watch the gauge. You need at least 61 PSI to start the engine.

If maximum fuel pressure is low: Check the battery with a load type tester. AutoZone will do it for you. A weak battery will cause a no start, as the fuel pump needs max voltage to get the fuel pressure up to and above 61 psi, which is needed for the engine to start.

3) You need to check each and every plug for spark. Just because one plug has good spark doesn't mean the rest do.

Let us know what you find - it will help others.

12-08-2006, 05:12 AM
Look at ECM Bat and ECM IGN fuses, then if spark out the coil, then a new Delco cap and rotor would be the next step assuming the fuel press test was good (over 60psi), especially if its an aftermarket cap even recently - seen failures on several and some have spark but to multiple cyls at same time. May not be the fix but for $50 it rules that out and a dealer visit will be over $200 to look at it - been there. Next area would be look at the crank sensor and connector.

01-20-2008, 09:16 PM
I have the same year s-10 blazer and had the same problems. First I would put a jumper wire from the positive battery to the pin leading to the fuel pump. Have someone listen for the pump to kick on. If ti does kick on you prolly have a break in the wire leading to the relay, or a bad relay. I ended up finding a break in the wire going to the relay to tell it to turn on. I think it was a small blue wire and it was broke under the brake booster. Hope that helps Ive had alot of problems with the wireing on that thing.

01-20-2008, 09:21 PM
Please check the dates on threads before posting, this one is over a year old. Thanks

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