Injectors read 14.5+/- ohms on all. Injector plugs is what I'm not sure about.

 

well order of elimination would be...is your car parked on a high slope ?try adding 2 more gallons..maybe gauge is giving false reading....
then check fuel pump,filters.injectors..take one out and watch it spray if your really angry,,,you replaced your ecm...so it has to be one of the above or the alarm...the injectors themselves didnt all die at once...check the fuel pump relay or fuse..injection relay or fuse?all the fuses and relays!!

 

The VATS code occurs when you aren't getting reference pulses from the distributor to the ECM and the ECM is not able to pulse the injectors. If VATS were active, the start enable relay wouldn't close and you wouldn't be able to crank the engine so your problem is not the pellet or the ign tumbler contacts that make with the pellet.
A test light should not light up when connected between batt neg and the ECM side of the FI socket key on. This shows that the ECM injector driver for at least the socket you checked is on all the time which should not occur. Also, the test light should not light between batt pos and either side of the inj socket key off. One contact on the FI socket goes to 12v switched on by the ign switch and the other contact goes to the ECM driver which is a transistor used as a switch to ground this contact with a pulse according to info from the distributor (the right time) and the TPS (wider throttle causes longer pulse duration). Also, 0.3 ohms across inj sockets #1 and #3 should not occur and may be the cause for the injectors not pulsing as 12v will be forced onto both wires of the injector. I would try to find out why there is a short across injector sockets 1 and 3. Unplug the ECM and see if 1 and 3 are still shorted.

 

jfb-thanks - will try after work. I hate electrical probs.

 

Finally got home from work about 7:30. Picked up old ECM from parts store. Before attaching, did the following:
1- Attached a 12 volt test to neg side of battery and tested "hot" side of #1 injector plug and ECM side with key on. Both sides lit up.
2 - Did same test on injector #6. Same results
3 - Attached tester to pos side of battery and tested "hot" side of #1 injector plug and ECM side with key off. Both sides lit up.
4 - Did same test on injector #6. Same results
5 - Check ECM plugs (not attached to ECM) and found only 1 pink/blk wire. Checked with tester on neg side of battery and key on. Tester lit up.
6 - Followed left wires from injector shroud to the large loom behind the distributor.
7 - Followed right wires from injector shroud to the large loom that appears to go thru the firewall.
8 - Checked ohms between #1 & #3 FI plug. Pink wire "hot", blue wire from ECM (disconnected) pink to pink 0.2 ohms; blue to blue 0.2 ohms, pink to blue 7.3 ohms
My thoughts are that somehow I got crossed/shorted wires somewhere. However, it would seem that it would blow the fuses and they are ok.
So the questions of the day are....do the wires from the FI's go thru the firewall and to where? do they go directly to the ECM? is the a way to check continuity from the FI plug to the "begining" of the wire?
I'm sure I'll have more questions, but if I can answers to some of these, it's a starting point
Thanks in advance
Subman


[Modified by subman, 11:38 PM 6/22/2004]

 

When I get home I'll have access to my electrical service manual. I am certain that the injector wires go through C100 and then to the ECM. You can unplug the ECM and check for continuity from the ECM wiring harness pin to the FI socket pin.

 

jfb - THANKS! will look for it when I get home - I have a funeral for one of my employees mom tonite so it'll be after 8:00.

 

The injectors on each bank of cylinders are in parallel and each bank has the FI wire that goes to the ECM go to a firewall connector on the right side of the firewall near the ECM. On my 87 these two wires are blk/pink (odd # cyl) and blk/lt grn (even # cyl). With all the FI's unplugged and the ECM unplugged, the FI socket pin that goes to the ECM must measure infinite resistance to ground (ign off) and they must not have any voltage on them with the ign key on. With the ECM plugged in and ign on but engine and starter not turning, there should be very low voltage (I would guess less than 0.3 volts) on the FI-to-ECM pins. If 12v shows on this pin, then the ECM must be defective (unless somehow a 12v wire is touching either FI bank wire). Also, ECM and FI sockets unplugged, all FI sockets must have infinite resistance across their pins. A low resistance across any banks socket will prevent the ECM from pulsing the injectors on that bank. There must be continuity from D15 ( odd cyls) and D16 (even cyls) of the ECM to the appropriate bank of FI socket pins. With ign on only, each FI socket must have 12v on the black wire on each FI socket. And....while the FI's are unplugged, measure the resistance from one pin of each FI to ground. It must measure infinite resistance.
Let me know if I can help any further. Good luck.


[Modified by jfb, 6:54 PM 6/23/2004]

 

jfb - thanks for the info - didn't get home until 9:30 last night so I'll tackle this nightmare tonite. Your 87 injector wires are a different color than mine, but I think I can translate. My ECM is over the battery on the left side, so the routing may be a little different. I wish I was better at this electrical stuff. Most of the time it just gives me a headache.
Thanks again
Subman

 

After almost a week of testing, looking, searching, following the help (as best I could) from jfb, I gave up last night. Called J & D Corvette and I'll take it to them tomorrow. I will find out what the problem(s) were and post under a new topic so maybe another member can fix it faster.
Thanks to all the members who offered their help and knowlege. This place really does rock!
Subman

 

Sorry to hear you threw in the towel. It will be interesting to learn why the injectors weren't being exercised.