bbhall89

Ok so here's what I've gotten so far. I have a 318 grand cherokee that I've replaced the fuel pump given a tune up changed fuel filter and tried changing sensors on but i think that's where the problem lies. Anyway long story short the damn thing won't start and now is throwing an error code number 24. I've since then put the old sensors back on because this code says the tps isn't the right voltage or doesn'tcorrelate with the map. And it still won't start. Did i trip a fuse and just don't know it? Its a94 and I've checked the fuses in the engine Bay and in the dash on the passengers side.are there more somewhere that i don't know about? Could there be a bad relay somewhere? Any helpwould be awesome.

dave1123

Check your throttle position sensor for proper voltage. You should have a 5.0 volt supply. The output should be 0.2 to 0.9 at idle and increase smoothly to 4.5 at WOT. You'll have to get a diagram to know which pins are which. You can at least check for the 5 volt supply. If you don't have that, check the plugs on the PCM and your grounds. With 5 volt sensors, grounds are critical.

bbhall89

Will i be able to check it if it doesn't start? Cuz that's the problem I'm having now. I cranks but didn't turn

DSMchad

as long as the ignition is turned on to the "run" position you should have voltage to the sensors, it may show just under 5.0v since the engine wont be running

does the fuel pump run? have spark?

bbhall89

Yes I've checked to make sure i have both. I didn't check all wires but i know i do have spark coming thru. The weird thing was when i replaced the tps it started right up then ran for about 5 mins so i shut it off then started it again and it died and wouldn't start again and is now throwing that code. But i will check the voltage of the sensor. And any idea where the ground is for that? Or should i just try to go thru and clean all i can find.

dave1123

I'm not sure, but I believe the sensor grounds thru the PCM and it's ground wire.

bbhall89

This is what I've gotten figured out. I went with daves advice and checked the connections at the main computer found that the plug was not plugged in right. So if someone has the same problem check the plug and make sure the pins are inserted right. That's where the power supply is and the grounds for the tps and map sensors.

bbhall89

After starting it and driving it a few blocks i noticed if i go to WOT it Boggs down quite a bit to the point of almost stalling. I can get the RPMs to about 2300 before it does so..then when i brought it back home i checked the voltage at the map sensor and it read out as follows.
Black/blue red/white 3.61
Black/blue purple/white 4.61
Red/white purple/white .93
I started looking for different grounds hoping something would show but nothing. That was about the time it died on me. And wouldn't start up again. So I'm once again..back to square one. Do i need to start checking connections at the ignition? Do i need to try to chase those wires thru the harness (not what i want to do btw) oh and those voltage readings are when its plugged in and not plugged in as well. And the tps is pretty well the same too..please give me thoughts, ideas, advice.

DSMchad

that to me almost sounds like a bad TPS

bbhall89

I checked the voltage again and tried it everyway i could think of, tps unplugged, map plugged
Map unplugged, tps plugged
Both plugged,
Both unplugged
The voltage was the same every time. I could have a bad tps but i think there is another underlying problem.