njstreetrx7

I JUST REPLACE my front wiring harness, everything went well. car started up first time but now car starts but then shuts offafter like 3 sec

THINGS I CHECKED - all fuses under dash
-all fuses in engine bay
-swapped relay for fuel pump
- unplugged fuel pump resister under the brake booster(to see if i it was bad car wouldnt start up w it unplugged) so that works

WHAT ELSE IS RELATED TO FUEL OR IS THIS PROBLEM EVEN FUEL RELATED<A FRIEND OF MINE THINKS SO

Also if i try o press gas b4 i shuts off the car autamtically shuts off

WHAT ELSE CAN I CHECK

thanks!!!

Upgrayedd

iTrader: (1)

Check your MAP sensor (Labeled "Boost Sensor" attached to driver's side firewall) hose? If it came disconnected during the labor it could be the culprit and an easy fix... It's happened to me a few times

njstreetrx7

YEA I CHECKED THAT thanks anyone else

sabotageU

Can you hear your fuel pump come on when you put the key to acc? If all of your fuses, relays, and ignition wiring to your relay is okay then I would break out a voltmeter and check all of your wiring. Make sure you have a good ground and good connections. I am pretty sure something is either not connected or a bad ground. Check your fuel pump relay with a voltmeter first. Good luck

by the way, I once replaced my fuel pump relay and 100% of everything else that had to do with the fuel system (even replaced my fuel pump) and nothing fixed the problem. Come to find out the new fuel pump relay I had put in went bad immediately because a little water was setting where I plugged it in at. I dried it out and put a new relay in and it worked perfect. Make sure there is no moisture in there.

Mahjik

iTrader: (1)

You changed the main wiring harness? If so, did you verify that you put the CAS connectors in the right order?

njstreetrx7

cas connectors??? whats that
edit: o i know those were never touched, i only replaced front main harness not engine harness

thanks any other ideas

njstreetrx7

i always thought if the fuel pump wasnt working the car wouldnt start everytime.

GoodfellaFD3S

iTrader: (213)

Crank Angle Sensor connectors. There are two of them, the sensors are down behind the trigger wheel. White connector on top, grey connector on bottom.

njstreetrx7

bump

sabotageU

if the fuel pump isn't working then it will start a few more times and die off but soon it will just stop starting period.

treceb

did u check the nut behind the wheel?

fastlinetuning

there is way to little information here to work with. the first thing you need to do is find out if it is spark or fuel. the best way to find this out is pull a plug wire and leave it off the plug a half of an inch, then watch the spark jump when it dies. without that info there is not much anyone can do. never assume anything.

njstreetrx7

how can it be spark when i didnt touch the engine harness

njstreetrx7

bump?

scotty305

iTrader: (2)

Quit trying to chase what you "think" might be the problem and just troubleshoot it logically. An engine needs only a few things to start: air, fuel, spark, and compression. It also needs these in the correct sequence.

Since it fires up and catches, it's pretty safe to say you've got compression and spark, but it wouldn't hurt to double-check. Compression testers are less than $50 from an auto parts store, that's a pretty straight-forward test. For spark, you can either connect a timing light to your plug wires to verify they're firing, or remove one spark plug lead, connect it to a spare spark plug, and hold that plug near the shock tower and look for spark.


Install a fuel pressure gauge and check to see that you've got enough pressure. The factory service manual has info regarding the correct fuel pressure, as well as where to monitor fuel pressure.

The OEM fuel system has a vacuum-controlled fuel pressure regulator, if it's not connected to engine vacuum that will screw with fuel pressure, possibly enough to let the motor fire up but then die.


Just to be thorough, you might want to double-check all the fuses and make sure nothing is blown. The ECU gets power from one source while cranking, and another source when it's not cranking.


Try pulling your spark plugs to see if they're wet or dry after the motor dies. That might give you some helpful insight.

-s-

njstreetrx7

Car Was Running. Then I Replaced The Front Harness! Anyway Thanks To All For Help It Was A Shorted Out Map Sensor

GoodfellaFD3S

iTrader: (213)

What do you mean by 'shorted out'?

njstreetrx7

because its just broken .....reading 5v atand car isnt even running...should only read 5v at 17psi (max)