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-   -   1997 454 no start, no fuel, no spark..wtf? (https://chevroletforum.com/forum/tahoe-suburban-25/1997-454-no-start-no-fuel-no-spark-wtf-42923/)

chevy2500-454 June 2nd, 2011 9:03 PM

1997 454 no start, no fuel, no spark..wtf?
 
I have a 97 454 Im trying to help a single mother get running. This truck wouldnt start for her one day and we got alot of rain and she couldnt get it started after the rain she said it fired right up? She drove a few days and again no start. She has another friend that offered to help her? he pulled the tank down thinking it was simply the fuel pump. Then just left it all apart? So I went and dragged it out put it all back together with a new fuel pump since the one in it was under warranty. I cranked on it after getting the mess back together and nothing. I get to cking and I have no spark either so I was thinking crank position right, wrong. I put a new one on and nothing new occured. So now I'm thinking ecm and coil?

How can you pull the dist cap and rotor? Do you have to pull the upper intake? How can you get that coil out of there seems like a mess? unless you pull the upper plenum, is their another way?

I appreciate it to all that have read this in hopes of helping me out. I also appreciate any feedback from you guys in the know...

I must also add I have power at the coil just nothing coming out of it..I also have power at one of the pins for the ecm.

chevy2500-454 June 4th, 2011 10:34 AM

bump for anyone have a clue in here?

73shark June 4th, 2011 9:26 PM

Were you getting fuel pressure w/ the new pump?

RacerX June 4th, 2011 10:13 PM

does it crank?
how do you know you are not getting spark?
do you hear the fuel pump relay close and pump whir?
do you hear the ECM relay close when you turn the key to run?

chevy2500-454 June 5th, 2011 9:32 AM


Originally Posted by RacerX (Post 183127)
does it crank?
how do you know you are not getting spark?
do you hear the fuel pump relay close and pump whir?
do you hear the ECM relay close when you turn the key to run?

its cranking..

I put a timing light on the spark plug wires, then I put in on the coil wire.

I dont hear the fuel pump whirring.

where is the ecm relay? I know it has power going to the coil and ecm but no power coming out of it when key is on.

RacerX June 6th, 2011 6:49 AM

If you get spark then the ECM is on and the ICM is functioning. But if you dont hear the fuel pump whir when you turn the key, check for fuel pressure on the schrder valve. If you press it and no fuel comes out then it is either the FP Relay or the fuel pump.

Find the relay bank and if you can locate the fuel pump relay, turn the key to Run and the put your finger on the relay. You should feel it click closed for 3 seconds and then click open. If you dont feel a click, switch it with another similar relay(A/C relays are best) and try again. If you feel it click and you crank the motor and you dont have fuel pressure then the pump is no good.

RacerX June 6th, 2011 7:10 AM

I m sorry man, I still dont know if you are getting spark. In #1 you say no, but in #5 you say yes.
Check the Ignition Control Module. And you have to test that for Resistance. I dont know the measure but if the Ohms are within range.

chevy2500-454 June 7th, 2011 8:12 AM


Originally Posted by chevy2500-454 (Post 182951)
I have no spark?
I must also add I have power at the coil just nothing coming out of it..I also have power at one of the pins for the ecm.


Originally Posted by RacerX (Post 183127)
how do you know you are not getting spark?


Originally Posted by chevy2500-454 (Post 183147)
I put a timing light on the spark plug wires, then I put in on the coil wire.


Originally Posted by RacerX (Post 183204)
I m sorry man, I still dont know if you are getting spark. In #1 you say no, but in #5 you say yes.
Check the Ignition Control Module. And you have to test that for Resistance. I dont know the measure but if the Ohms are within range.

I have NO spark..in 1 I said I have no spark and you had asked how do I know I have no spark. So in 5 I advised you I put a timing light on the wires to determine I have No spark. thanks for the posts tho.

RacerX June 8th, 2011 6:23 AM

I misunderstood, I though you had spark. ECM=computer; ICM=spark module.

If you have NO spark, then take out the ICM and check for resistance. If the resistance is way out of range or unmeasurable replace that. A bad or intermittent ICM will not give you spark at the coil. This is a 97 so it would make sense the ICM has failed. I will have to look this up but I think on this car the ICM is under the coil and the coil is in the center of the cap. 4 tiny long screws and the cap comes off and 2 prongs to detach the coil.

Somebody else will confirm this until I can look at a manual for a 454.

Since you did the fuel pump, you do have fuel pressure right?

chevy2500-454 June 9th, 2011 8:25 AM

I got it RUNNING..

The fuel issues were all caused by one a bad fuel pump relay and two a disable fuel pickup. When the other person partially pulled it down they pulled the ground out of the pickup entirely and you couldnt even tell it was missing it either.

The no spark was a damaged rotor button...I changed the cap and rotor as well as cam sensor and still wouldnt start.

I had replaced the crank position sensor upon first starting this escapade. I swapped that back to my original crank sensor and she started right up....so I had bought a new crank sensor that was damaged.

I appreciate the feedback...SHE IS NOW RUNNING PROBLEM FIXED...


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