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1998 chevy tahoe issues. Please help.


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Juan7913
New User

Mar 24, 2017, 11:07 PM

Post #1 of 3 (180 views)
1998 chevy tahoe issues. Please help. Sign In

https://youtu.be/EK8ao5bkeiw

Read the description and i know im bad at using my words. But can someone please help me with some pointers on my situation. Im fairly new at working on cars by myself.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Mar 25, 2017, 4:20 AM

Post #2 of 3 (166 views)
Re: 1998 chevy tahoe issues. Please help. Sign In

New to any of this noted. First - what is the 8th digit of your vin - # seen thru windshield looks like it should be an "R" meaning a Vortec 5.7 or looked mostly like one.


Then fuel pressure test should have been done before you replaced a fuel pump to see what it was if anything or didn't hold.


Right now would be nice to know from a check list what is missing following this right here for an "All Crank, No Start" situation which is what I see.


I can't hear fuel pump do anything AFTER you turn off key just take your word. Link to go thru here............


http://autoforums.carjunky.com/...LL_NOT_START_P75655/


An evap emissions code doesn't mean much yet as you had the tank out and things unplugged so dismissing that right now. If you disconnected the battery as you should have by almost any suggestions to do a fuel pump you've lost all codes that were possibly helpful now.


One thing noticed in the video is a silver button or a pilot light maybe on the three small panels on dash - the top one of the three isn't a factory anything so what is that?


If this has an aftermarket alarm system or "disabler" it's either working properly because it's been messed with or failed. If so you have to know how to reset it and could be only that is actively preventing it from running?


Know that plug to fuel pumps on some of these vehicles was a problem spot. It must look clean and make a proper connection and match up. It looks like a Vortec engine which is a high fuel pressure engine that really like original equipment fuel pumps not aftermarket plus none like running dry or low on fuel.


If an "R" engine pressure should hold at 60-66PSI as I recall and will NOT start or run well or at all if much below 58 - that fussy,


T



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 25, 2017, 4:24 AM

Post #3 of 3 (164 views)
Re: 1998 chevy tahoe issues. Please help. Sign In

I don't know how you came to the conclusion that your issue is even with the fuel pump in the first place. The cycling part is normal.

Here's where you need to start. Before you do anything, make sure you don't have a security light staying on or flashing when you try to start it.


All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.



Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.



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