Autozone has a NOID light for free. Just a tool deposit. No need for buying and not using for years.

 

OK, just came back...to re cap, the fuel pump test checked out ok, the pump came on again after i did a brief attempt to start it.
all injector wires are reading a pos read out. I tested all 8 and both wires at all 8 injectors and they read 12.5 I believe ( i replied to a msg from you with original readings) i want to remind you I also tested the injectors for ohms and they all tested 16.5.

I tested the TPS middle wire while hooked up, key on and paper clip thrugh back side. middle wire tested .5v without me touching throttle. at wide open throttle it read 2.96
the top black wire on the TPS acted pos with 0.56V without me touching it
the bottom grey wire tested pos with 5.02 v without me touching it

battery read 12.42 v
volts at fuse INJ1 read 11.91v both sides of fuse
volts at INJ2 read 11.91v at both sides of fuse.

I tested all fuses, and they all acted as they should. a couple had really low V. but reacted the same on both sides of the fuse.

If I unplugged the TPS and tesed the plug on the wiring harness with key on, it read:
top, black 0.03v
middle, blue 0.05v
bottom grey 5.02v

While the key has been turned on, something has been clicking/chattering around the intake, I can not tell what it is. it does not stop clicking when the TPS was unplugged. UPDATE..THIS WAS BECAUSE I HAD A+B terminal looped with a paper clip

I do not have access to a noid light. and do not have anywhere to borrow one. I have seen many times a test light will do the trick. I will see if I can track one down, but I assure you, it is not flashing. As for the fuel pressure, I do not see an easy way to put a fuel pressure gauge on here ( like the tire valve someone mentioned) I am unsure if I will be able to check that either. but I know there is preasure in the rails. if I take a plug out, and turn the key, gas shoots out. ( yes I know, its the PSI thats important. )

Anyways, just thought I would post an update on the stuff I tested today.

 

The injector circuit is ground side switched !!...to check for injector pulse you hook up a 12 volt test light to battery POSITIVE and probe the control side of that circuit !!...with the car running or cranking over you should see the test light blink as the car is cranked or running...it will be dim though !!...and was previously mentioned a 12 volt test light is NOT high current !!...I've been doing it this way for YEARS !!...my test light drawing 140 Mv is not high current !!!

 

Yes, I am aware how to test and that the pulse is given by the neg and holding the test light to pos bat terminal and other end to injector. they do not pulse that way. they never pulse. I have been testing it as you described.

someone else was asking for me to test for the pos volts at the inj plugs.

THIS CAR DOES NOT HAVE NEG INJECTOR PULES!!!!!!!.

 

I have no idea what you mean by the car "DOES NOT HAVE NEG. INJECTOR PULSES" ???...I am confused by your terminology !!...you have 12 volts coming into the injector on one wire and the PCM/ECM grounds the other !!...you also said.... " I tested all 8 and both wires at all 8 injectors and they read 12.5 I believe"...you shouldn't be seeing 12.5 on both my friend !!

 

you read it correctly...thats what is messed up. when key is on, I have 12 volts coming from both pig tails on the injector wiring harness.

I agree, I don't think I should be seeing 12.5 on both...but I am.

You are not miss-understanding me. something is not right. the car is not running...the car has no pulse the injectors pulse from a neg signal sent from the computer, you just said the same thing that in order to check the pulse you have to test the injector plug with the other end of the test light going to the PS of the battery ( hence a neg pulse) it does not pules. no neg pulse.


The way you are "trying to explain to me" how the injectors should be working, I am already aware of. that is not how they are testing on this car

 

I'm not 100% sure if you can do a "clear flood crank" on a C4 as on the C5...maybe one of C4 guys can let me know...if you push the gas pedal to the floor while cranking this will inhibit injector pulse and the car will not start !!...you said you checked the TPS so when I get home later I'll check out the TPS circuit !!...this may be the problem if you are getting no injector pulse !!...the PCM thinks the gas pedal is pushed down to the floor...you would check the voltage with key ON and by back probing the signal wire and ground !!

 

that is how I tested it. however the black wire does not act like a ground. it reads 0.05v.

I just tried to start it. and now the "security" flashes while its cranking. I swear it didn't before.

 

If you have an Autozone nearby, they can let you take a NOID light and a fuel pressure gauge. Just leave the deposit money and get it back when you return within 90 days

 

Borrow the NOID light or buy it. I don't think you can test it. AFAIK, when there are pulses the ECM will GROUND the line to fire. Hot always but NOT grounded till the ECM commands it.

 

Yes it will so unless you depressed the pedal all the way representing a clear flood mode, there should be pulses which you cannot see since the positive side is hot and your meter is on the ground of the battery.

 

I checked the circuit and it’s a pull up design and it looks like if the PCM sees more than .54 volts with the key ON back probing the signal wire (dark blue) to ground the car won’t start...I believe you said you had .5 but is it more than .54 volts ??

 

I have also tested with the meter on the pos of the battery, no negative is registering.

there is no autozone where I live. Different country. I assure you there is no pulse. and I am testing it right.

 

I don't think so. People have cranked it up to supposedly get better response. Close to.0.7,IIRC. I think it has to me way more to get into clear flood mode.

 

I think that the NOID light uses both terminals of the injectors. If I use a DVOM I would use both too. So you can see when the ECM grounds the system. Negative terminal does not help since it will never ground itself and the system is already hot.

 

I think if you are going to measure injector pulses, it should not be checked against battery ground. It should be with the 2 wires of the injector plug.

 

You can check injector pulse with either a noid light if you have one or with a test light !!...it’s NOT hard !!

 

Thanks !!...I knew it couldn’t be that low of a voltage !!...on a C5 it’s about 80% throttle angle !!

 

I know it's not hard. I am already aware that there is no pulse on this car. I said that in the opening comment on this thread.

 

you can check it two ways. one by looping the test light between both connectors on the injector pig tail. and then crank engine

OR you can put one end on the bat POS and the other end on the injector connection on the pig tail. test both sides out. one should pulse while cranking