I have a 91 TPI setup on my truck with 19 lb mustang injectors and a custom chip w/o vats, and the engine will not start. I checked all the grounds and there was continuity on all of them, I have spark and I have fuel in the rails. I checked for voltage at one of the injector conectors and I had 12 volts at both sides of the plug. I don't think the injecotrs are opening. What should I start to check?

 

https://www.thirdgen.org/techbb2/sho...hreadid=123320

 

Thanks for that link. The only code I get is 12. The distributor is a new unit, but i think it was for a tall-deck big block (I got it for free from my freind who works at a chevy dealer). Is there any way I can check for a drp without a scanner?

 

If you have spark, even if the dist wasn't the right height, you should have a DRP to the ecm unless the module is bad like it was on the other thread. I have never checked it but I *think* you should see 5V and some type of frequency out of the reference line (purple wire with white tracer) with a DMM but that's just a guess.

 

I tried a new module and it still did not start. I had a snap-on scanner on it, and it showed 0 RPM when cranking. Does this signal come from the drp? Are all large external coil distributors the same? What should I try next?

 

ok... so you have spark.... and you are wondering if you have any pulses going to the injectors. go out to pep boys, and buy the little injector test light. it cost all of 3 bucks, plug it in, and you will see if you are getting a pulse going to the injectors. try this on the left and the right sides. if the light blinks your ok. next test the fuel pressure. see if you are getting about 42psi, and holding it. if you get 42, and it bleeds off, wait 10 sec and prime it back to 42, then crimp the fuel lines. If it still bleeds off you might have a leaky injector. if it holds, uncrimp one of the fuel lines; the small one comes from the fuel regulator, if you uncrimp this one and fuel pressure bleeds off, you should change that; the big one is the fuel pump, if you uncrimp this one and it bleeds off, the fuel check valve in the pump is bad, and you'll need to drop the tank to change it.

if the pressure holds, and you get pulses to the injectors, your fuel system is ok and you need to look elsewhere.

Good luck,


Joker

 

OK i got the injector test light and hooked it up, no pulse when cranking. I have 12 volts at the positive injector wires and continuity to the ground pins on the ecm connector and I have fuel pressure. What should I try next?

 

ok... no blinking light means the injectors aren't firing...

is it this way on both sides? if one side pulses and the other side dosen't, first check the fuses. there are two, one for each side.

if they are ok, it might be something with your prom, or your ecm. the computer should be sending a signal to the injectors to fire (directly from the ECM), of which the vats could cause it to stop, or a general ecm failure.

of course, it could just be a short between the injectors and the wiring harness, but that will be a bitch to find. the wire to injectors 1,3,5,7 is blk/pnk (from the ecm) and is numbered 467, check the continutiy in that one, and in blk/ lt grn 468 for the other cylanders. if either of them is not shorted it is most likely a faulty ecm.

thats as per the factory book.

Have fun,

Joker

 

I just got the PROM wensday from Jim's Performance in Maryland and he took the VATS out for me. When you say shorted, you mean the positive wires going to the injectors are shorted to ground, right?

 

yeah... the way it works is that the injectors get power from your fuse block, then ground out through the computer (which is how the computer controls the pulses). the wires i gave you start from the end of the string of the injectors, and lead to the computer. if the wires are broken, but still inside the casing (like when you kink a wire, but it breaks and still looks ok from the outside) you might not be getting a ground signal to turn the injectors on. you just got the prom burned? if so try the old prom (if you still have one, assuming they didn't reburn your old one) and see if it gives you a pulse to the injectors. if so you might have a bad prom, or who ever put it in might have hurt the ecm in some fashion.



joker

 

I don't have the old prom, that didnt pulse the injectors because it has VATS. What should the resistance be on the ground circuit for the injectors?

 

good point with the vats thing.

the continuity should be zero, or close to it, because you are only checking for continuity. with a dimm, it will read a value like -1 or something to show that there is no continuity, and give a real value if there is (ie if the wires are connected, you get a real value, if not they give an impossible value that is set in the dmm)

do you still have your old key? you could probably read the resistance from that, and use a resitor to bridge the old wires that lead to the vats module, thus letting you use the old prom. its and idea, but it depends on how much of the old system you took out.

 

I don't have the key or VATS module. The setup is on my 71 truck in my sig

 

I tried a new ECM and it still doesnt start

 

If the injectors aren't firing then the ECM isn't seeing the reference pulse from the distributor. Without the pulse it will not fire the injectors. You need to findout where the pulse is not getting through.

 

It's a new distributor and ignition module, and I tried another new ignition module and still no pulse. If I hook a test light to 12v and touch the ppl/wht wire the fuel pump comes on, so theres continuity back to the ECM. What else should I try? Is there any way to check for a reference pulse while cranking?

Edit: if I rotate the distributor with the key on, the fuel pump relay will come on for 2 seconds like when you first turn the key on. Does this mean the ECM is getting a drp?

 

I unplugged the ECM and turned on the key, the I looked for voltage at BC11 (odd injectors) and BC12 (even injectors). The test light lit up at BC12, but not BC11. Then when I plugged the ECM back in, they would both light up. Is that normal, or do I have a break in BC11? Also, the P/N switch is closed in park and neutral, correct? Thanks for the help guys

 

You either have a break in the circuit or a blown fuse for that side on the injector key on power feed. The P/N switch is used for IAC operation and has nothing to do with it not pulsing the injectors.

 

The fuse is good because I get power at the injectors on that side, so a break in BC11 does make sence. How come I get power at BC11 once I plug it into the computer?

 

The odd injector fuse was blown, so I replaced it. Still wont start

 

Did you ever get the truck running? Actually, has the truck ever run with the TPI? I ask because maybe your problem is the PROM. It may have not been burned correctly or has corrupted data. Some folks have had a PROM start up fine after burning one only to have it mess up a few minutes later. I would start to look there. You said you had someone burn a PROM for you w/o VATS. I'm sure you've already seen the threads about PROM burning and that you can get started for about $250, minus all the bells and whistles. I would guess that's what the custom burnt PROM cost you.

 

Nope, it hasnt ran with this setup yet. I had the chip burned by Jim's Performance last week, it was $140 and Jim was very helpful. I have winbin and a pocket programer 2, I tried doing it myself and I had a little trouble (1st bin file was corupted, couldnt get any response from the ECM at all once I got a clean bin) so I just had one made to get the truck running, and I would try burning an extra one I had after that. How do I save a mask from the chip I got from Jim's without harming it? I have the adapter so I don't have to take the PROM out of my memcal.

 

You mean you want to save the bin he has sent you right? What did he send you, a PROM by itself or a whole memcal? What memcal do you have or better said what does it say on it? AUJP or something?

 

Yeah, I want to save the bin he sent me. He sent me the whole memcal with the prom in it. On the prom is a sticker that says 5.7 - M - (350 manual trans) and my last name on it.

 

Aahhh, I would dare guess that is your problem. Maybe it got shocked with static or something. To read the PROM you need to stick a header in the PROM part of the memcal. If you don't have a header for it you may try the excess that comes off of resistors and stuff but you gotta be careful. Since you have prom burning stuff and an adapter, try it and forget the prom you have. Get AUJP and turn off VATS. There are several sites that have a copy of AUJP. It's for an auto and has 22 lb inj but it's just to see if it works.

 

How do I save the bin off the chip using the pocket programer 2 software? Where can I get some flash proms from locally? They cost more to ship than buy, I would rather just go somewhere on my way home from work and pick a couple up instead of paying shipping. Also, where can I get a new memcal? I don't have any extras, just the one from Jim's

Here's the bin I was using. http://chrisd71k5.i8.com/aujp1350.bin

 

To read the chip you have to do like I told you in the last post. You have to stick a header in the PROM part of the MEMCAL and put it in the PP2. Go to the PROM burning intro article and look at the pictures in it. I believe Trax goes into detail.

I don't live in Jersey but I would guess any good electronics store. Around here there is a place called Alpha electronics but I doubt they're a nationwide chain. They would also have the header you need to stick into the PROM.

You can get a new MEMCAL from your GM dealer or from gmpartsdirect.com. It's about $85 from the dealer and about $50 from the online site. Part # 16151348.

Try the bin from diy-efi.org or from Mike Davis' site. The link to both are in the PROM burning intro.

 

OK i can get the memcal into the PP2 w/ the header, but once I'm in the PP2 software, how do I load the bin off the prom and save it? All I know how to do with the PP2 is burn a bin that already exists on my computer, not the other way around. Is there any sites where I can learn how to use the PP2 software? They're site hasnt been to helpful with that

 

On PP2 software, hit "move device" when you have the header and prom inserted. Make sure you have selected the right eprom. Hit "verify device" just to make sure it read the data right or "edit buffer" to actually see the data. Hit "save buffer" to save the bin to wherever it is you want to save it to.

There is a document in the EPROM file created when you load the PP2 software. Actually, there may be more than one. Those are all you need to know to work the PP2.

 

Here's the .bin I saved from the Jim's chip (this is what's in the truck now). I selected 27C256 for the PROM in the PP2 software, because the PROM had no ID on it and it looked like the stock PROM. I opened up the file in Winbin and it looks like everything Jim told me he would change was changed (VATs disabled, fan temps, injector constant, EGR disabled).

http://chrisd71k5.i8.com/Jims.bin

 

I figured out that I am getting an injector pulse. I hooked up my voltmeter to the ppl/wht wire on my 89 Blazer w/ TBI and got 1.44 volts when cranking. I tested the same wire on my TPI truck and got the same reading, so there is a pulse. What else can I check? Could it be the injectors themselves? that's the only part that's not new

 

That's just the reference pulse to the ECM. You still don't have injector pulse. Try burning a PROM without VATS and see. It's something in the PROM not letting it pulse. Better yet, try it without the prom and see if it starts on the limp home chips.

 

I tried starting without the PROM and nothing happened. I saved a mask from the Jim's chip (uploaded in the link above if you want to look at it) and the VATS was deselected

 

Any update yet?

 

The injectors in this setup were questionable, so I ordered new ones. They came off a EFI setup that was taken off a wrecked 5.0 Mustang, and then they sat for a year after that. Some of my freinds w/ mustangs said they experienced fuel delivery problems with injectors that had been sitting for extended periods of time. I was going to install them tomorow, but they changed my schedule at work (again ) so the next day I have to work on it is Sunday. I'll know then if they work

 

I just got the new injectors in, and it still wont start. Now, the noid light will flash when I let off the starter, what does this mean?

 

Top. Anyone got any more ideas? If it's not raining out tomorow, I'm going to check the resistance of all the grounds. What should the ranges be?

 

Grounds should be 0 or very close, I would look into any ground that has more than 10 ohms.

 

All grounds are .4-.6 ohms, from the ECM conector to the negative battery cable. The noid light will still flash when I let off the starter, why is this?

 

It runs! I had the ignition trigger on my Painless Circuit Boss hooked up to the wrong source , and it wasnt getting ignition power in start . I moved it to my CB power and it fired right up (kinda). The timing is way off, so I need to get that set then let the idle learn, then I can drive it

Thanks to all that helped :hail:

 

okay i did this, i have continuity on all injectors aboue 10 ohms, and i have power to the injector harness, but no blinking light. I am just using a normal 12 volt test light,i am not getting a blink on either side of the connector. I have used two different books, it says i have bad ecm is this the case or is there another test i can do?