mjdavis68

iTrader: (1)

88 5.7 TPI - Was TPI originally and DA put a carb on it and im going back to the TPI- Upon engine cranking the oil pressure is 50 psi and the "safety switch" is new. according to this im not getting 12v power to my injectors D15 D16 and i have power on the 2 second fuel pump prime-fuel pump is new and i did jump it and its runs. So i dont know, please help me

http://chevythunder.com/fuel%20injec...ecm%20#1227165)

86Z

iTrader: (4)

did he change the distributor when he went to carb? the distributor sends a signal to the ecm to fire the injectors

mjdavis68

iTrader: (1)

i put the correct one back...pink and white wires right

vetteoz

iTrader: (13)

Pump run and injector pulse are unrelated items

D15/16 are the grounds at the ECM to make the injectors pulse ; not the 12V supply to them
Do you have 12V at one injector terminal , key on ?
If not check the 2 injector fuses ?
Have you tried a noid light on the injector plug to see if you have injector pulse ?
Is VATS disabled in the memcal you are using ?

mjdavis68

iTrader: (1)

i haven't checked the 12v at the inj
fuses are good
no noid test
No vats on car

jman1234

i had no injectot pulse check power to injectors with multi meter goot piwer grate now get oms meeter check every injector should have 16.5 oms on all of rm if one is under 12 ohms it will shut pulse down all together if you find one is bad un plug that injector and try to start i had one injector bad on bouth sides of fuel rail i unpluged one bad one it started right up then found another bad one on outher side of rail unpluged it ran much better but now i got to replace injectors but bad inkectors will shut down injector pulse completely my car only ran for two seconds at a time thrn i did this hope it hlps you good luck

mjdavis68

iTrader: (1)

The injectors are new and havent run yet but i will the connectors

mjdavis68

iTrader: (1)

Ok today i pulled all the wire loom off the engine harness so can trace these dang wires-

I have a single Black/White wire thats cut- the main single wire from the ECM i guess, turns into a soldered bundle over by the Firewall that 1 goes to the engine block 2 goes to the fuel pump relay 3 goes to the maf burn off relay next to the fuel pump relay and the other is the one thats cut! can anyone tell me if this is where they actually go and where the other one thats cut goes please?

Thanks to anyone

mjdavis68

iTrader: (1)

Im giving myself a Bump as i hope to get some direction here

8Mike9

Chilton electrical diagrams are pretty good, not as complete as a Helms, but should give you a place to start.

Where does the b/w wire come from that was cut?
I'll look in my 89 manual if I have a place to start from.

mjdavis68

iTrader: (1)

from the ecm it looks like
thanks

8Mike9

A black wire with a white stripe, is for the ECM ground and will/should also go to pin B on the fuel pump relay connector from ECM pin A1.

It looks like some has hacked into your harness as ECM pin D1 should go to ground and pin A on te MAF sensor, not MAF relay (according to my '89 manual.

D3 from the ECM (these are all black/w white stripes) should go to ground and to the MAF sensor power- realy

It seems as though for some reason, the PO decided to tie them all together...unsure what the reason for that might be.

mjdavis68

iTrader: (1)

Well i appreciate your help! i will go check on this and hope i can get it sorted, im not very patient with this kind of automotive stuff.. Im not gettting a fuel pump prime either. the 2 second signal is there at the ecm and no injector power from the ecm....I just dont know, i just have to educate myself as im trying to save this car.
But i Thank you, Mike in Dallas

mjdavis68

iTrader: (1)

Oh and the "tie all together was wrapped in OEM loom tape and has not been tamperged with, only the cut wire i mentioned

And whats the difference between Ground and System Ground

8Mike9

I've not heard of system ground...the ECM has internal ground (as mentioned above via the quad drivers) and your car has ground from the batter, to the engine block, etc, that the external sensors etc, use---these will be behind and on the heads, between the firewall.

Let's separate the issues, as noted before, they most likely are not related.

Now, if you pull out the connector at the Fuel Pump relay and jump pin A to Pin E, the fuel pump should turn on..pin E should be 12v, and pin A should run to the FP.

mjdavis68

iTrader: (1)

Hey sir, i went and checked it, it does not power the pump, but the stupid thing is the Burn off relay next to it clicks!! man i have a mess

8Mike9

No worries, it's supposed to, now you need to trace back the FP wiring...wht did you "jump out" before to get the FP to run?

Edit:

It should turn on the MAF Power relay, not the burn off relay.

mjdavis68

iTrader: (1)

i just tapped in to the Tan/Wht wired after the fuse block just to see if it works and it does. I need to get these wires sorted before i try a new ecm or something...

mjdavis68

iTrader: (1)

Now, if you pull out the connector at the Fuel Pump relay and jump pin A to Pin E, the fuel pump should turn on..pin E should be 12v, and pin A should run to the FP.


Now what do i trace? which way? it did run the FP when i jumped the relay. so where do i go from here....

Thanks

8Mike9

What I mentioned was bypassing the relay, at the relay connector...gimme a bit to look at my schematics and let me see if I can figure out what you did, so we can talk apples to apples

mjdavis68

iTrader: (1)

Ok thays,... i put the jumper on the relay like you said and nothing happened with the pump , only the relay on the right of it CLICKED when i was applying the jumper wire?

8Mike9

Okay, the tan/w wire is what the ECM used to monitor the fuel pump voltage for error code, that wire ties in directly to pin A's wire that heads to the fuel pump.

Now the 64 dollar question is where does the tan.w wire connect to the Pin A wire...reason I say this it seems that at some point where it ties into and up to the FP relay connector, there is an open in the wire...I would assume that the voltage monitoring wire (tan/w, would be under the hood and in close proximity to the relay, (if not crimped to the A wire at the relay connector), which wold lead me to think a bad connetion, etc, at the connector crimp.

Gimme a few minutes...well, at least a few beers worth, and I'll pop my hood and see if I can spot the tan/w wire.

8Mike9

It might be tied in at the MAF power relay (the one you are hearing click). It's getting a bit darker now, and I don't see two wires together to the FP relay.

Do you have a DVM/DMM or an ohm meter?

mjdavis68

iTrader: (1)

Man, i wouldnt know what to do with it, i could learn and educate myself though, Also look at my other thread as i was fishing for answers and this C207/C221 popped up....

Crap the computer im using wont let me copy the link but here.. Whats this plug by my ECM