02 PR5 Crank, No Start

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Mazda Protege5
Hello Id like to start by saying Im new to the forum community and was recommended that I join one to diagnose my car. I just picked up a nice 02 Mazda Protege5 That wasnt running when I got it. Previous owner had told me that there was a small fire in the fuse box and the car wouldnt even crank. He also told me that he had a new motor installed. Upon further inspection, a few terminals were dried in the fuse box as expected, but the engine bay just seemed off somehow. He had many aftermarket accessories installed that looked like a diy job, so I thought he just overloaded the electrical system. Once I got it home, I got to work by tracing each and every aftermarket accessory and uninstalling it. Knew the fuse box was fried so I ran over to pick your part and grabbed a mediocre one from a junker. After testing each fuse/relay and installing the other fuse box, I was able to get the car to crank but it still wont start. Im experiencing the issue where the Temp guage would jump to HOT with the key in the on position. My current suspicions are now the timing belt since its a new motor, wiring harness because of recent short or overload, or the fuel pump/fuel delivery system. Sorry for such a long post but Im just trying to get it to run and enjoy the car! :(:
 

pcb

The Diagram Dude
:
2002 MP5
I wouldn't even know where to start if I were you ??
If you're thinking your T-belt has snapped, you can remove your oil filler cap and look down while cranking. If the cam isn't turning, your belt has snapped.

If your temp gauge is pinned to hot then you have at least one broken or shorted wire. Just having the ECU think your car is hot when it's not is enough to keep your car from starting.

Start with the basics and check for spark and for fuel.

This is the big list of things to consider.



This is a link to the factory service manual. There's information about how to test all the sensors and systems to try and find your problem.

https://www.mazdas247.com/forum/sho...actory-Service-Manual-PDF-download&highlight=
 
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protege5
Hello I’d like to start by saying I’m new to the forum community and was recommended that I join one to diagnose my car. I just picked up a nice 02 Mazda Protege5 That wasn’t running when I got it. Previous owner had told me that there was a small fire in the fuse box and the car wouldn’t even crank. He also told me that he had a new motor installed. Upon further inspection, a few terminals were dried in the fuse box as expected, but the engine bay just seemed off somehow. He had many aftermarket accessories installed that looked like a “diy” job, so I thought he just overloaded the electrical system. Once I got it home, I got to work by tracing each and every aftermarket accessory and uninstalling it. Knew the fuse box was fried so I ran over to pick your part and grabbed a mediocre one from a junker. After testing each fuse/relay and installing the other fuse box, I was able to get the car to crank but it still won’t start. I’m experiencing the issue where the Temp guage would “jump” to HOT with the key in the “on” position. My current suspicions are now the timing belt since it’s a new motor, wiring harness because of recent short or overload, or the fuel pump/fuel delivery system. Sorry for such a long post but I’m just trying to get it to run and enjoy the car! :(:

I don't know what kind of mechanical ability you posess, but buying a non-running vehicle is always a crapshoot. especially if there was enough of a short to smoke the fuse box, there is likely wiring harness damage somewhere that you're not seeing off hand.

it may be a simple fix, it may be a cheap fix if you know what you're doing. However it looks like a pretty involved "project" by the sounds of it. There are some pretty knowledgeable people on here and a lot of helpful folks, and pcb seems to have some sort of fetish with scanning diagrams and pages from the repair manual to help you along lol

if you've got a healthy toolbox and knowledge of auto repair (particularly on the electrical side from the sounds of it) you have found the right place to offer advice. However if you're not real mechanically inclined and don't know a considerable amount about auto electrical diag and repair, my advice would be to craigslist the thing before you sink a ton of time and cash into it to end up frustrated, burnt out, and no closer to having the car run in 6 months than you are right now. Without being in front of the car and having the see/touch/feel/taste experience, our help is only as good as your basic abilities to take the advice and run with it. No miracles happening here or magic fixes, especially if there was a thermal event involved :)

Not to try and be debbie downer, I just have a love/hate relationship with project vehicles. I love project vehicles but HATE when the previous owner thinks it's an "easy fix" and gets in over their head, and creates 300 new problems trying to fix the original one. I go through a lot of "project atv's" and always end up getting them running but especially when it comes to electrical, 9 times out of 10 there are hacks/bypasses/and stuff chopped up in the previous owner's "attempt" to fix it of stuff that was never broken to begin with and just creates a ton more work to undo all the unnecessary chopping they did trying to fix it.
 
:
Mazda Protege5
I don't know what kind of mechanical ability you posess, but buying a non-running vehicle is always a crapshoot. especially if there was enough of a short to smoke the fuse box, there is likely wiring harness damage somewhere that you're not seeing off hand.

it may be a simple fix, it may be a cheap fix if you know what you're doing. However it looks like a pretty involved "project" by the sounds of it. There are some pretty knowledgeable people on here and a lot of helpful folks, and pcb seems to have some sort of fetish with scanning diagrams and pages from the repair manual to help you along lol

if you've got a healthy toolbox and knowledge of auto repair (particularly on the electrical side from the sounds of it) you have found the right place to offer advice. However if you're not real mechanically inclined and don't know a considerable amount about auto electrical diag and repair, my advice would be to craigslist the thing before you sink a ton of time and cash into it to end up frustrated, burnt out, and no closer to having the car run in 6 months than you are right now. Without being in front of the car and having the see/touch/feel/taste experience, our help is only as good as your basic abilities to take the advice and run with it. No miracles happening here or magic fixes, especially if there was a thermal event involved :)

Not to try and be debbie downer, I just have a love/hate relationship with project vehicles. I love project vehicles but HATE when the previous owner thinks it's an "easy fix" and gets in over their head, and creates 300 new problems trying to fix the original one. I go through a lot of "project atv's" and always end up getting them running but especially when it comes to electrical, 9 times out of 10 there are hacks/bypasses/and stuff chopped up in the previous owner's "attempt" to fix it of stuff that was never broken to begin with and just creates a ton more work to undo all the unnecessary chopping they did trying to fix it.

I have about 4 years of highschool autoshop experience and I was always pretty involved with the builds or troubleshooting of the various cars we had in so I think i should have some understanding. The thing is most of the time it was mechanical issues and not electrical. My father is an electrician so we've been trying to collaborate and find the problem. As of right now we are almost sure there is a short in the wiring harness that is causing the car not to start. I've read many of the forums about the relays going bad and ive made sure that my relays are clicking and they have no resistance in them. After taking apart the old fuse box assembly, my father examined it and said that it was fine so i went ahead and threw the old one back in. I cleaned up the terminals and threw some dielectric grease on them to prevent further issues before putting it back in. When i turn the car to the "on" position, i dont hear the fuel pump prime so im thinking that there is a short in the wiring somewhere between the relay in the fusebox and a component of the fuel system. Whoever installed the new engine did a hack job on the wiring in the engine bay and ive been finding various ground wires that were either in bad spots or just disconnected completely(Maybe this caused the issue). Prev. owner said it sat for 3 weeks and he got the engine installed ALSO 3 weeks ago. Thanks for the inquires!
 

pcb

The Diagram Dude
:
2002 MP5
Remove the square cover under the backseat to get a better listen for the fuel pump... You may not be hearing it.
Put your finger on the fuel pump relay to see if you feel it clicking.
You could remove it then plug it in with key in "on" position to help identify the click.
The relay and pump don't "necessarily" turn on with key in on position if the fuel pressure is sufficient.

Remove a plug and wire, and check it for spark or just stick your pinky in the sparkplug wire, that works too. (haha)

If you've got spark, that's half your battle.
 

pcb

The Diagram Dude
:
2002 MP5
Make sure you download the P5 wiring diagrams.

This is a schematic that isn't included in those diagrams.
(It's one of my extremely rare fetish pictures never seen before on the forum !! Enjoy!!)



Short out the F/P terminal under the hood to make sure your fuel pump circuit is powered.



 
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pcb

The Diagram Dude
:
2002 MP5
Remove a plug and wire, and check it for spark or just stick your pinky in the sparkplug wire, that works too. (haha).

See if your plugs look wet,... If they're wet, you're probably getting fuel.
 

pcb

The Diagram Dude
:
2002 MP5
You can test for voltage on all your fuses.
Probe the little metal tabs to check for +12 V

I'm pretty sure (but not positive) that ALL fuses should show +12 V on those tabs with the key turned to "on".

(some may only go to +12 V while in "start" mode but I don't think so)



 
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Mazda Protege5
Ok so I went ahead and tested the relay and terminals by doing what you said(turning car to “on” and plug in the relay). The relay was clicking so after I tested that I went ahead and removed the square panel that covers the fuel pump and listened for it and couldn’t hear anything(turned ignition to “on” position). I even tried using the mechanics stethoscope, but still...nothing.
 
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Mazda Protege5
Tested the fuses using my multimeter but most of them were reading .000 and a few would jump around .230-.400. None of the fuses are blown and the ignition was set to “on”.
 

pcb

The Diagram Dude
:
2002 MP5
Tested the fuses using my multimeter but most of them were reading .000 and a few would jump around .230-.400. None of the fuses are blown and the ignition was set to “on”.

Are you testing for voltage with the red lead going to the fuse tab and the black lead clipped to the frame or a bolt.
 

pcb

The Diagram Dude
:
2002 MP5
It's actually better if your pump doesn't run with the F/P wire grounded.

That means the power wire going to the pump needs to be replaced.

If the pump runs in"test" mode but not while your trying to start your car it means your ECU is saying "No way" this ain't gonna happen.

It's receiving bad/incomplete or no data from some sensor somewhere.
 
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