Cadillac Repair: 1997 Cadillac Deville, rapid acceleration, cadillac deville

Question
I m sorry for jumping around.  The cranking for several seconds was the reason we took the car to the mechanic. He replaced the spark plugs first. That did not help the starting problem so we took it back and that is when he replaced the fuel pump.  Replacing the fuel pump did not fix the starting problem and that is when the missing out began. I hope the sequence of events will help you help me.  Sorry for the confusion.  Let s work on the starting problem first.  -------------------------    Followup To    Question -   Would a bad spark plug account for the cranking for several seconds before starting?  -------------------------    Followup To    Question -   My cadillac sometimes is very slow in starting.  We have replaced the fuel pump which did not fix the problem.  We also now have a problem with the engine feeling like it is missing out. If We pass a car with rapid acceleration it seems to run fine, but as soon as we slow down it runs rough. The spark plugs have been replaced.  Our mechanic has not been able to diagnos the problem.    Answer -   Did it run OK before the plugs were replaced ?. If so, You probably cracked one during installation,.    Answer -   Would a bad spark plug account for the cranking for several seconds before starting?  NO !!!!!.      Which question are we going to work on FIRST ?.  

Answer
Would a bad spark plug account for the cranking for several seconds before starting? NO it would not.

Just because a fuel pump is new does not guarantee that it is 100% operational.

Fuel pump test:

1. Get yourself a helper.

2. remove the gas cap.

3. have one person listen in the gas tank at the gas cap opening.

4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.

5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.

6. Does it ?.

7. If it does NOT run for the 2 seconds the fault is either the fuel pump or the fuel pump relay.


Honestly, without having access to the vehicle to perform some routine tests the possibilities are endless.