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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hi guys. I just finished building g my engine bay. Been working on the plugs and wiring of the car. For some reason I keep blowing the fuse beside the battery. I've traced everything and find no exposed wires. Any ideas?
The fuse powers the ecm and the fuel pump.
if either is shorted the fuse would blow. If the fuse pops while both are unplugged than the orange wire is shorted to ground.
Is this speed density ? I don’t see a maf ?
Mines an 87. First gen gta. Does that make a difference? And if you could clarify. If I unplug the ECU it means the fuel pump. If I unplug the fuel pump it's the ECU and if I unplug both it's the (now inline fuse)? It started doing it when I plugged Into the fuel pump relay. Does that help?
As you can see the wire powers the maf power, ops, ecm and fuel pump relay.
It could be a pinched wire grounding . If it started when you plugged in the pump relay check the wiring at the relay and try it with the pump disconnected at the rear body connector by the tank to see if it’s the pump itself.
The pump is newer but I will check that tomorrow. I believe it has to do with the wiring to the relay I just have to figure out how. I will do as you suggest and reply back here tomorrow with my findings. I appreciate the immediate response.
The chip also deletes the maf and burn off from the ecm.
Who made this chip? As far as I know that's not possible and have it run any kind of decent. They may have deleted the codes but it should still have the MAF sensor.. I would bet my lunch that it's running like crap in limp mode for all these years. You can't delete the MAF from a 7165 ECM with a "chip"
That ground a few replies back has nothing to do with the engine. That there is the ground for cruise control and/or the fog lights.
You can unplug a MAF and the ECM will default to a set of values to allow the engine to sorta run, but it's certainly not optimal or desirable. Just as a general blanket statement, EFI either has to measure the air flowing into the engine so it can meter the proper amount of fuel, or it uses a MAP sensor to calculate air flow based on engine vacuum. But all that is beside the point. A fuse blowing indicates there's an electrical problem, not a fuel management issue.
The greater issue is that without a fundamental understanding of how a system is designed and intended to work, you can't very well go about trying to improve on that design by modifying it yourself. You go changing things and hacking away, then when you've thoroughly screwed things up, you can't go back to the well of knowledge seeking advice. The system is no longer how it's supposed to be. The only person knows what you've done, what you've changed, is you, and you clearly have no idea what you're doing.
I'd tell you to put down the Sawzall and step away, but it's too late now. I wish I could have been there for you brother.
What does your engine now use to measure the flow of air it intakes?
Nothing.
Didn't you read the thread, he cleaned up the engine bay and beautified it by throwing away all that ugly stuff that made it actually start and run. Now it's a bonfire looking for a place to combust. It's no longer transportation, or an automobile, it's yard art with a sole redeeming quality of being a 3000lb tool to test the failure point of fuses.
That ground a few replies back has nothing to do with the engine. That there is the ground for cruise control and/or the fog lights.
You can unplug a MAF and the ECM will default to a set of values to allow the engine to sorta run, but it's certainly not optimal or desirable. Just as a general blanket statement, EFI either has to measure the air flowing into the engine so it can meter the proper amount of fuel, or it uses a MAP sensor to calculate air flow based on engine vacuum. But all that is beside the point. A fuse blowing indicates there's an electrical problem, not a fuel management issue.
The greater issue is that without a fundamental understanding of how a system is designed and intended to work, you can't very well go about trying to improve on that design by modifying it yourself. You go changing things and hacking away, then when you've thoroughly screwed things up, you can't go back to the well of knowledge seeking advice. The system is no longer how it's supposed to be. The only person knows what you've done, what you've changed, is you, and you clearly have no idea what you're doing.
I'd tell you to put down the Sawzall and step away, but it's too late now. I wish I could have been there for you brother.
Originally Posted by Drew
Nothing.
Didn't you read the thread, he cleaned up the engine bay and beautified it by throwing away all that ugly stuff that made it actually start and run. Now it's a bonfire looking for a place to combust. It's no longer transportation, or an automobile, it's yard art with a sole redeeming quality of being a 3000lb tool to test the failure point of fuses.
Drew isn't wrong. You ABSOLUTELY CANNOT delete the MAF (without going to speed density with EBL, or rewire to a 7730, etc) on a 7165 ECM and it still be "right".
It may run, but you are leaving a lot of performance and driveability on the table.
Regardless of what you *think* is happening, without the MAF, the 7165 IS IN LIMP MODE without it's MAF.
GD
Last edited by GeneralDisorder; Apr 3, 2019 at 12:15 PM.
Didn't you read the thread, he cleaned up the engine bay and beautified it by throwing away all that ugly stuff that made it actually start and run. Now it's a bonfire looking for a place to combust. It's no longer transportation, or an automobile, it's yard art with a sole redeeming quality of being a 3000lb tool to test the failure point of fuses.
LULZ
Originally Posted by GeneralDisorder
Drew isn't wrong. You ABSOLUTELY CANNOT delete the MAF (without going to speed density) on a 7165 ECM and it still be "right".
It may run, but you are leaving a lot of performance and driveability on the table.
Regardless of what you *think* is happening, without the MAF, the 7165 IS IN LIMP MODE without it's MAF.
GD
^^^^THIS.
It's "comforting" to realize that bodybuilding/fitness/nutrition forums aren't the only internet sites where confused posters ask oddball questions.
The wire isn’t going to be purposely grounded. A short to ground is caused by a hot wire connected directly to ground or a component shorted out. Sounds like with the wiring being tampered with there is a loose wire maybe at the maf power that’s shorted to ground.
I'm still trying to wrap my head around "I just finished building my engine bay" followed shortly by a picture of the genesis of a rust hole in the same engine bay that is theoretically "finished".
What do you mean "Ignition coil"? I got an emissions delete chip! Don't need that **** cluttering up the place. John Force doesn't need no ignition coil, and neither do I!
That whole corner is looking fairly scabby. But perhaps it needs a good cleaning. I do see surface rust on more than one fastener for sure. That "chip" you bought is clearly a scam if you have no MAF connected and the SES light isn't on. That's basically criminal, or at least criminally stupid.
GD
Last edited by GeneralDisorder; Apr 3, 2019 at 02:33 PM.
No rust just leaves. Paints chipping a little from where the PO did a paint over and didnt prep proper but the rest of the car is immaculate. No rust. No dings or dents. Whole reason I bought the domestic.
Its run fantastically for years with no issue. No limp mode. No issues. This is the same setup my father ran in his down the track for years.
Oh man, you have one of those "John Wayne custom chips". At least, that's what his name was before he got removed from the most popular thirdgen facebook pages for scamming people.
Another note that everyone else has made plainly clear, you need a MAF (or MAP depending on year) to run the car properly.
To be honest, it grinds my gears when people remove things because "It'll look better" without those components. Save yourself the trouble and do the research before you start yanking out the most critical components of the engine bay.
might as well run a carb 
