My iroc-z Tpi 350 motor wont start unless i put fuel straight into throttle body, then it dies after like 3 seconds when that fuel is gone, I have been told everything is bad from spark plugs, ecm, fuel regulator, fuel pump, injectors, and vacum hoses. Now im not planning on replacing all of these and hopefully just one so I have narrowed it down to most likey be a bad fuel pressure regulator, stuck injector, or bad ecm and I bought a fuel pressure tester and with key on it is at 45 psi, which means fuel pump is good, but hw do i use this fuel pressure tester to check fuel regulator?

 

you did just check the regulator ! what years is your car 89-92 ? sounds like you are missing injector pulse a vats issue.

 

I though that checked the fuel pumps pressure, because dont I have to see what the pressure is when trying to crank it to know if the regulator is bad, or just with the ignition key on works.
Also I am unsure of year but like a 87, or 88 and what do you mean missing injector pulse, and how can i confirm this as im a newbie to these tpi motors, thanx

 

Get a noid light to check inj. pulse.
Get a spark tester to for spark.

 

what he said !! Post the letters off the memcal in the ecm. I will tell you if it has vats

 

What? I already bought a fuel pressure tester, and I have no money except $50 on ebay which is for the part thats going to need to be replaced, so Is the fuel regulator and fuel pump good? And i thought that checking the injectors with the eletrical tester for the rite ohms means they are good?

 

Oh and here is what happened when i was driving it the other day before it had this problem. So i was going up and down a road to run some gas threw it and after about 5minutes i was driving then i floored it and it went then kinda acted like it ran out of gas untill i let off the gas some then it died after a few seconds after sputtering some more, and it rolled like 5 feet from my house then it wouldnt start and thats it. Now i replaced the spark plugs the day before, and they are the same as the last set that were in it, and they are good since it will still run for a few seconds with the gas straight into throttle body, also I though it ran out of gas when it died but the next day i put like a gallon in it and the fuel was full to the filler neck and stays there, and If something is clogging the tank it wont make a difference in my starting problem since i disconnected the line at motor and had fuel go everywhere.

 

noid lights are cheap you can buy just the one you need.

http://lmgtfy.com/?q=injector+pulse+definition

 

like post #4 check for spark and injector pulse you may have a bad icm !

 

Do you want to fix your car, or just P&M about this?

Nobody out here can tell you what's wrong with your car if you don't go out and troubleshoot it. We can tell you what to look at, but YOU have to look at it. If that requires buying a tool, then ... you gotta buy a tool.

Now that we've got that childish behavior out of the way:

If the car starts when you put fuel in it, then the reason it won't start otherwise, is because there's no fuel. Duh. YOu already know that.

The reason there's no fuel is because: (a) there's no fuel pressure, or (b) the injectors aren't delivering it.

(a)

Use your new fuel pressure tester to test for fuel pressure when you turn the key to "on". Should jump up to something around 42 - 45 psi and sit there; maybe bleed off slowly, like a psi every few minutes.

If it doesn't do that, then either the pump is bad, or it's not getting electricity.

You should be able to hear the relay click. If not, then you have a problem with either the ECM, the wiring, or the relay. Check for 12V on the 2 smallest wires with the key "on" and just sitting there. One of them should have 12V whenever the ign is "on"; the other should go to ground for around 2 sec shen the key is first turned "on", then go to 12V after that. The relay should pull in then drop out. There should be 12V on one of the 2 large wires at all times. The other should have 12V on it during the 2 sec interval. If all that is OK, then the ECM, wiring up to that point, and relay, are all good.

Go do that test and come back with the results.

(b)

Measuring the injectors' ohms and thinking that a good reading guarantees that they are working, would be about like measuring the ohms of a light bulb and it be good, and then expecting it to light up in a lamp whether it's plugged in or not. They gotta get power in order to work. They should have 12V at all times on one of their wireswhen the key is "on", and when hooked up to the other wire the noid light should blink when the engine is cranked. This indicates that the ECM is telling them to fire. No tell, no fire. No 12V supplied to them, no fire.

Go check the injector pulse and reoprt back on the results.


Put on your big boy pants, and no more P&Ming about "poor". The car does not care. Either you're committed to fixing it and will do what it takes to enable yourself to get it done like a grown man, or we get to ignore you.

 

It's cheap to diagnose do what is posted above .

It sucks trying to chase issue but it takes less then a couple mins to do ..

 

Ok well for one im not just going to go buy every tool that is suggested to me by just any member as half the people are just guessing what it is, and thats all anyone can do but all i was meaning was before I go buy this part is ther anything i can do to check anything else first so I can narrow the list down to what it could need then go buy that 1 or 2 tools and get it done, instead of being a complete idiot and just buying any and every tool that is suggested, Now back on topic.
I dont understand which wires ur talking about in this post and where are they located?
(You should be able to hear the relay click. If not, then you have a problem with either the ECM, the wiring, or the relay. Check for 12V on the 2 smallest wires with the key "on" and just sitting there. One of them should have 12V whenever the ign is "on"; the other should go to ground for around 2 sec shen the key is first turned "on", then go to 12V after that. The relay should pull in then drop out. There should be 12V on one of the 2 large wires at all times. The other should have 12V on it during the 2 sec interval. If all that is OK, then the ECM, wiring up to that point, and relay, are all good.) Thanx oh and is my fuel psi supposed to drop to 22 psi when i press the release button then go back up to 45psi on my fuel pressure tester

 

What number off the memcal in ecm? Oh and what did you mean by spark tester to check for spark and where would i be looking at for the spark, the spark plugs, distributor?
And one last question where are these so called fuses for injectors that i read about in another thread?

 

ummmmm maybe the fuse box sounds like you have trouble even checking your oil maybe you need to have it towed some where.

 

The motor is a tpi motor out of a iroc-z swapped into a 89 s10 so everything isnt going to be the same, and the fuse box under the dash is the s10 trucks old one and its the only fuse bbox on the vehicle so how does this work exactly, as a iroc and a s10 dont have the same fuse ports etc so unless im mistaken i dont see one that says inj fuse 25amp, it was just a simple question as I have never owned a fuel inj motor only carbed before, and Im only 16 so I need stuff put in plain english to understand it, thanx

 

Also where is the number you were talking about on some memcal thingy, is that just the ecm basicaly

 

Bank 1 and bank 2 injector are usually on 3 amp fuses. If you have power at the injectors keo on engine off it's not a blown fuse. If not start tracing your wire to see where the injectors are getting switched power from. Every thing post on here is in english not greek or arabic or any other language if you need things dumbed down maybe your dad can help hold your hand.

 

even if you find a blown fuse you will need to determine why it is blown. The only testing I hear is you may have intermittent spark and good fuel pressure.

 

Wow it seems when one guy posts a douche bag comment then just about everyone else does also.

 

As easy as it is for you to post the internet has search engine's use them

https://www.thirdgen.org/forums/dfi-...om-calpak.html

 

So unplug the injector and set my meter to volts and just touch the pos, and neg to the two pins from injectors with key on and if i get 12 volts its good, or what did you mean

 

??? Im sorry if that is a stupid question but I really dont know for sure

 

back probe the injector connector with it plugged in use a paper clip or safety pin. with the key on you will have 12v dc.

 

The injector plug wont push back on witht the paper clip there so would a little chunk of soldering iron wire jambed in between the plug and injector work?

 

http://lmgtfy.com/?q=back+probe+definition

 

unsubscribed !

 

OK, so I guess you just want to call people trailer-trash names that are willing to take the time to help you, but you aren't willing to put yourself out to make it happen.

Fix it yourself. I can't be bothered any more.

 

I never called anyone a trailer trash name, and you werent helping as much as you were being rude to me, So if some one is helping me I am polite to them, but to someone that is being an *** (sofakingdom) Then I will not ask for their advice, as there are plenty of others helping that arent as rude about stuff.

 

So basicaly on that lmgtfy search it said to touch the probe on meter to injector plug connector so why didnt you just say so, it would have been alot easier to understand that. Thanx ill go check now

 

Ok so the volt meter set at 2000ohms and the 2 probes each touching on opposite sides of the injector plug wire it read 3 so whats that mean and what was this test to check for? thanx

 

You're welcome for me trying to help you. I won't make that mistake again.

 

[quote=sofakingdom;5480203]You're welcome for me trying to help you. I won't make that mistake again.[/quot
Ok well Im sorry about that but I guess you werent really being to rude in that one long post and I guess I took it the wrong way so I appolagize for calling you a douche bag but it felt like you and the other guy were attacking me in a way so i got a little heated, but i just went back threw the previous posts and now i understand that you were actually trying to help me, so im sorry

 

as sofaking dom has stated we wont't help you unless you help your self. read on the basic principals of a internal combustion engine. There are only a few things you need to make it work " that was a hint" . If you can afford a noid light get creative tough the injector or press a screw driver against at as a stethoscope and have some one crank it over and listen for a click. You will never see 12v on a resistance setting on your vom.

 

There's plenty of half-assed advice on the internet, but just so you know, sofa is the third gen oracle. If you're lucky your apology might be accepted. Do what he says, and you will be on your way to happy motoring at minimal cost.

 

Oh ok, I kinda get what your saying with the screwdriver but if the motors turning over how do i hear the clicking sound that i should hear come from the injector? and does this basicaly test the injectors to be good or not, or if the ecm is opening them?

 

So is there anything i can try while i wait on a noid tester which will be about a week or more from now.
Oh and will the kit in link below work with my type of injector
http://www.ebay.com/itm/9-Pc-Electro...3e7c23&vxp=mtr

 

like I said before just get the one you need there 8-12 bucks at the auto parts store. you would hear a clicking noise if the injector is pulsing

 

oriely's and autozone usually has them just get one that says mpfi gm or bosch

 

Here is a book you should read thanks to vetteoz

http://depositfiles.com/files/ty1vrpu