am pulling these codes on my 87 TPI. adjusted the TPS, which was not that far out of adjustment. the code 23 is throwing me off. book says it is a MAT sensor code. but, why would the otherr 2 codes pop w/ the 23? any help would be great!

and yes i did a search and could not find all these codes in the same thread...

 

guess i should have explained the problem a little better. was driving to work and the car just died. will crank but not start. what could be the problem? dont see how these codes are related to a no start problem??????

 

need some help guys...got a meet coming up and dont want to be w/o car.

 

was doing some troubleshooting on the issue the other day went and tested for fuel pressure at the rail and had nothing. the relys are less than a year old so im leaning towards it being the tank pump.

if it is, why would these codes be thrown?

 

Thats your TPS..Sounds like its way out of whack or its cooked

CODE 21 Throttle position sensor (TPS) circuit
(All)
-Sticking or misadjusted TPS plunger.

-Faulty or loose wiring/and or connectors at TPS and/or at the ECM.

-Faulty TPS.


CODE 22 Throttle position sensor (TPS) circuit
(All)
-TPS misadjusted.

-Faulty or loose wiring and/or connections at the ECM.

-Faulty TPS.


CODE 23 Manifold Air Temperature (MAT) sensor
-Faulty MAT sensor.

-Faulty or loose wiring and/or connections to the MAT sensor.

 

yes i know all this. i did check the TPS first, it is about a year old, and it wasnt that far out of adjustment. was nearly set at .540V when i checked it. i did reset it since i was already testing it.

i pretty sure its the tank pump, but want to be a 1000% sure b4 i go throught the hastle of dropping the tank to replace it.

to my knowledge its still the original. ive had the car for 2 years and i have never changed it.

when i bought it everything that could be seen was original.

 

Sounds like you may be right....So the pressure is reading zero with the ignition in the on position??

 

yes had nothing on the gauge w/ the key in the on position. did some furthur searching here and found a link to another site w/ a detailed troublshoting method i tried and it lead me more to believe that it is the tank pump.

will post more when im 1000% sure...

 

another reason why i believe its the tank pump or a fuel problem in general is, when the car sits for a day or so and i try to start it, it will run for less than a second then die. this tell me that the fuel in tha tank is expanding and giving enough pressure to far the car off for just a brief second.

still stumped on why these codes would have been thrown if the tank fuel pump is bad?????

someone out there must of had this problem b4...help me out here guys...

 

http://www.partsamerica.com/ProductL...hfor=Fuel+Pump

anyone have a experience w/ any of the pumps offer by advanced auto?

 

Just joined the forum about 5 min. ago. Hope you got your IROC going.
I swapped out the pump in my 87 IROC already. Kind of a bear getting the tank out. If I remember correctly, I think I cut the filler neck and reconnected it with a piece of approved hose. I prefer BOSCH fuel pumps PN: 69218 for your 350. They're a little more money but they do run quiet.

 

i bought a walbro pump got it for $117 shipped. going to start working on it today.

 

Might want to check the multitude of ground leads at the back of the passenger side cylinder head.

 

i dont think it is a ground. i was having starting issues w/ it for a while b4 it went. i had an 89 K5 blazer that was doing the same thing and died the same way and it was the pump.

and if its not it would have eventully needed it and im prepared to do do the work now. i have to ake the rear out anyway.

 

well replaced the pump and im still not getting power to it. its is getting power to the sending unit but the pump still wont come on.

going to try and replace the relay. dont know what else it could be if its not the relay.

any other ideas?????????????????????

 

Power to the pump runs through the fuel pump relay. I suspect you have a bad one.

Check this first:

Turn the key to on. The fuel pump should run for a few seconds then shut off. Do you hear the pump run?

If you want to verify that it's the fuel pump relay, check the photo in this thread:

https://www.thirdgen.org/forums/tpi/...ump-relay.html

Remove the fuel pump relay and the relay to the right from the bracket (to get access to the connectors). Unplug and swap the fuel pump relay with the one to the right. See if the car starts and remains running.

The other relay is for the cooling fans (IIRC) so you might not be able to take the car and drive it very long to see if it quits on you.

Before you replaced the pump, you could have by-passed the fuel pump relay by feeding 12v directly to the pump at the relay connector (a wiring diagram would be helpful). This would have saved you a bunch of labor.

Good luck.

LInk doesn't work. Here's the photo:

 

the pump does not come on when i turn the key. i replaced the relay nearly a year ago so i didnt think that was the problem.

i swapped the relays out under the hood and still get nothing.

 

If the pump doesn't run for a few seconds when you turn the key to ON position, then you need to find out if the relay is getting power.

Break out your wiring diagram and work your way from the relay back. Somewhere along the way you'll find the fault.

Typically, a relay has two circuits. One circuit operates a coil (electromagnet of sorts) which when energized, pulls two contacts together. These two contacts close the circuit that feeds 12v to the pump.

The FSM has a troubleshooting guide also.

 

i did do some troublshooting and i may have missed something. everything i did led me to believe it was the fuel pump.

im going to try and look at it again tomorrow after work.

my father in law, who is a mechanic, told me it sound like the module in the cap. he said there was 2 sides one for spark and one that controls the injectors and fuel pump. all the searching i did here on this topic none mentioned this. is this true? or is he mistaken?