barney10mm

ok , i bought this 93 . the pos. termanal on batt . was shorting out on the frame . im getting hot and spark everywhere . did major tune up ,getting no signal to injectors ,fuel pressure 41 .ohms , volts ,and fuses good . plez . help .

Cliff Harris

Sounds like the VATS isn't talking to the ECM. If that happens you get no injector signal.

If it cranks then half the VATS is working. That also proves the connection between the key and VATS module is OK.

Another possibility is a short to ground on the injector wires. Are the injector fuses OK? If they are, you'll get 12V to one side of the injectors. The ECM grounds the other side to fire the injectors.

navy_vette

Does it crank? That's the first question. I'm not sure about VATS half working. VATS was awesome... in the 90's. Now, it's just a pain. One thing you can try to do is a bit of a pain if you have to complete the process. Check to make sure the distributor is plugged up properly. I'm not pointing at the spark as you said that is good, I'm more worried about the control voltages. It's been awile since I have looked at this part of the drawings, but the distributor position tells which injector at what time to fire. Just my input. We had that problem with mine. Someone did a HORRIABLE splicing job to the distributior. It looked like they didn't secure the "fork" down all the way, and it spun and ripped everything apart...

rodj

VATS has two components; the fuel enable signal to the ECM and the operation of the starter enable relay

Not on a batch fire engine,all injectors in one bank fire at once.

The ECM however needs to see the ref pulse generated by the dist while cranking in order for the ECM to pulse the injectors.

Need to pull the codes.
Possible DTC 41 is one of them; loss of communication from CCM ( where VATS is ) to the ECM.Very common and frustrating problem on 93/ 93 cars

Calderone

wow another VATS Issue, what's going on !
Hey Barney,behind the IP Panel there are 3 fuses (at least in my 87)
you need to check where is your auxiliary fuse box and there is a single fuse
that says "CINJ" , check that fuse and check the left and right bank injector
fuses on your normal fuse box :

jaa1992

FYI - I parked my 92 for 4 months once because I did not check the CORRECT Injector fuses. They are not the same amp rating!
Check the INJ1 and INJ2 fuses again.

barney10mm

well you guys are great thank you very much . but it cranks great , got good spark . good fuel pressure ..........got no fuse behind ip panel . i checked all fuses with a meter .tomorrow we gonna check ohms and amps out of new dist . cap . i wounder if i blew the new emc or dist cap , cuz i still had the bad batt . in after put new 1s on .i did replace coil and icm after replacement of good batt .thx again , bruce barney

mintc

id love to c what u find out im in the same boat as u with my 92 im trying to figure out witch part to throw at it first the diizzy, ecm, or a vats delete chip

jaa1992

Get thee a factory service manual

barney10mm

i got # 1 fsm doesnt even have a wiring diagram for injectors ect , some one plez send me a link .

mintc

the injector pulse wires go r green and blue wires and go straight to the ecm on my 92 prob the same on yours ive got mine narrowed down bad ecm, good luck finding one, or a bad distributor, trying to locate an oscilloscope to test, or the vats signal that goes to the ecm to fire the injectors, which i have no idea how to test, and i doubt its the vats my first parts probably going to b the distibuter cause it already has 110,000 on her

barney10mm

thx

jaa1992

Multiport fuel injection: V8 VIN P
Fuel Control and Fuel delivery diagram is on page 8A - 21 - 6 in the electrical diagnosis section of my 92 FSM

Forgot to add - thats in book 2 of the two volume set.

Cliff Harris

You can check the VATS signal to the ECM with a voltmeter.

If you see 0 volts or 5 volts, it's bad.

If you see about 2.5 volts, it's OK.

mintc

what wire would that b?

barney10mm

if it cranks .............. not vats .............. plez sent link to inject . wire diagram ,