FrankenSho injectors do not fire

[Iron Bender]

Tom,
the paper sticker on the PCM reads H3Z1. Tonight I traced all the grounds. I went back and traced every wire outlined in the other woman article (although I used a CCRM vs individual relays). I grounded the injectors first during crank mode then directly without cranking and then made a LED test light wiring it backwards. No pulse on any test. Being aggravated I pulled the injector rails to bench test the injectors on low amperage. Small sparks when connecting the circuit but no clacking or any kind or any movement I could feel in the injector. Just pure silence. This must not be the way to test an injector. What additional information can I provide???
Jim

 

[Iron Bender]

One additional note. I have a C4 on the back of the 3.2 inline with an impulse generating speedo to fake out the PCM in case that makes a difference regarding the PCM number.
Jim

 

[Off Road SHO]

You should definitely be able to hear and feel the injector open with the 12 volts applied, and closing with it removed. I will go out to my shop and do the same test to make sure of it. I also have some cleaned and ohm and flow matched injectors from one of my many 3.2's that I could send you but that will cost you.

PS: I have a spare H3Z1 PCM

Tom

 

[Off Road SHO]

I take that back, or part of it. When holding the injector in your hand, you can feel it operating when you hit it with the 12 volts, but it is difficult to hear with the ***** ear. With the stethoscope it is loud. It also doesn't matter which side gets the plus 12 and which side gets the ground. And I see the sparking also, so if you're not feeling that little clicking, I would say your injectors are really gummed up. Hard to believe all six would be though.

Tom

 

[Off Road SHO]

Just to be sure we're on the same page, the injectors are not heated up with +12 volts until you turn the ignition key to run or start.

Stand all six upright and fill the inlets to the top with ATF or MMO (Marvel Mystery Oil) and let sit overnight. Both are excellent at freeing up stuck parts. Drain them of the ATF and then spray WD-40 in there to remove all the thick oil. You can then simulate a pressurized fluid safely with an air tank hooked to the feed side of the injector. With a constant pressure of 40-80 psi, operate the injector with 12 volts. If it's clear you will feel the air coming out of the two nozzle holes.

Tom

 

[Iron Bender]

Tom,
Thanks for testing the process on your end. I will double check them again tonight as I cannot believe all six would be clogged although this motor has been on the shelf for years. It has 18,000 miles on it out of a factory test car (I live in Detroit). If they are all dead as they were last evening (no sound (I will check with a stethoscope as well) or vibration), I will soak them as suggested. What is your feeling about a price for the injectors in your inventory? I will PM you with my address for the PCM.
Thanks again. You and others on this forum are great.
Jim

 

[Off Road SHO]

If yours are the stock purple ones, I have a set that has been cleaned, flow tested and Ohm checked that I paid 19.00 apiece for. So you can have them for 114.00 plus shipping and a 20.00 donation to the Forum. They do not have new tips on them.

I can ship them with the PCM to save you shipping costs if you think you still need the PCM.

Tom

 

[Iron Bender]

Thanks Tom. I am going to clean the injectors to see if that is the problem. I did confirm that this motor has been on the shelf since 1995 so it is worth the effort. The prices sound good. I will be in contact once I know what I need.
Jim

 

[kevinspann]

ATX PCM...I wonder if it's because there's no auto tranny hooked up to it. You may have to fool the PCM into thinking it's in park or neutral. The ATX also has a 4000rpm P/N limiter. I'm not sure if this is why it isn't firing the injectors though.

I'd almost want to get a manual trans car engine harness and PCM just to avoid that. There are ways around it though.

 

[Iron Bender]

Kevin,
thanks for the comment. Can you further define the 4000 rpm P/N limiter for this newby? I can wire a traditional neutral safety switch to the old style column then wire the PCM into neutral without any problem as there is no original position switch. What would a manual trans PCM offer?

I cleaned the injectors and rails tonight. They were plugged with loose black residue. On one injector the final filter screen fell out but I could not remove from the other five. They are soaking now. Still no sign or noise indicating they are free when fired on a battery. Will try again tomorrow or replace. These may very well be the problem.
Jim

 

[Off Road SHO]

Kevin means that the PCM will not let you rev the engine past about 4000 rpm's while it is being told by the Manual Lever Position Sensor that the automatic transmission is in Park or Neutral. The MLPS does this by putting a certain amount of resistance in the line going back to the PCM.


EDIT: If you put a resistor with a value of between 190-232 OHMS, between pins 30 (light blue with a Yellow stripe) and 46 (Grey with a red stripe), the computer (PCM) will think the original transmission is in Drive and will allow rpm's up to 7,250 or there abouts. I think that is the only job of pin 30.

Tom

 

[rubydist]

just to be perfectly clear, the rev limiter in the atx pcm does not prevent the engine from starting. it only limits the max rpm in park/neutral to 4k. so you can be confident that your lack of injectors firing has nothing to do with the rev limiter...

 

[Slo-Sho]

The CAMshaft position sensor tells the comp when to fire the injectors. Is it securely plugged in?

 

[Iron Bender]

I figured out the abbreviation meant a 4000 rev limit in Park or Neutral. I need to get better acquainted with the abbreviations everyone uses. My idea to eliminate this problem is to solid wire the position switch to the PCM in the drive position then independently wire a neutral safety switch to the shifter. How does that feel to you? Still no movement or noise from any of the injectors after 24 hours of soaking. One more overnight then I guess I will replace.
Thanks again.
Jim

 

[Iron Bender]

yes we are good with all sensor connections to the PCM, CCRM and the grounds. Given the gunk in the injectors and the number of years this motor sat on the shelf (since 1994) I am beginning the believe it is a mechanical problem. I am soaking the injectors now for 2 days. If no movement tomorrow I believe they will all hit the trash can.
Thanks for the comments.
Jim

 

[pjtoledo]

where 'bout in the Detroit area are 'ya?


Perry

 

[Iron Bender]

16 mile and Woodward - Troy/Birmingham/Bloomfield area. You coming up for the Dream Cruise?

 

[rubydist]

The CAMshaft position sensor tells the comp when to fire the injectors. Is it securely plugged in?

^^ this is somewhat misleading. the cam sensor tells the pcm when cylinder #1 is at tdc, so that it knows how to set up the initial firing sequence at startup - that much is true. however, a SHO with a missing cam sensor can be started, and once started it will run normally, and the above suggests that a missing cam sensor will result in a no-start condition - which is not the case.

without the cam sensor, the pcm has to guess which cylinder is #1, so it may take 3-5 cranking tries to get it to start, but once started it will run normally (although with no tach indicated).

and, even with a missing cam sensor, the injectors and spark plugs will be fired, they just may or may not be fired at the proper time with relation to the crankshaft orientation. so, the failure of the injectors to fire has nothing to do with cam sensor.

 

[Slo-Sho]

Maybe get a can of starting fluid and try that? If the motor fires the PCM and ignition side can be totally eliminated as suspect.

 

[pjtoledo]

16 mile and Woodward - Troy/Birmingham/Bloomfield area. You coming up for the Dream Cruise?

I might, missed the last few years.
Usually meet an old friend near 11 1/2 mile.