CamaroHotRod

Who's a wiz at TBI motors ..

HERE ARE THE FACTS:
Just did a full harness and engine swap into a 85 car ..
My injectors are not spraying fuel .

test light shows no power or ground at injectors.
-->Test light on the Postive wires (red & white) on tbi harness on each injector shows no power when test light is grounded. [two tests, one while key was just in on position and other test during cranking. both showed negative]
-->each ground wire (blue & green) on each injector is not getting grounded[via hot test light to trying and ground it out on blue or green wire. [two tests, one while key was just in on position and other test during cranking. both showed negative]

-->tbi harness is from an 1988 305 camaro, harness worked find when i pulled it from the car last month.

-->ECM is from a 1988 chevy c1500. (with a 350) the truck ran when i pulled the computer.

-->the motor is from an 1989 k1500, intake, cam, headers tbi spacer. other then that its stock.

-->i had a custom chip burned, although i can not confirm this particular chip is good, the person i had burned the chip for me i have had success with other chips of theirs in different TBI cars. [VATS was suppose to be turned off with the chip burning]

-->fuses and good and fuses are HOT at fuse panel on INJ a INJ b and ECM fuse.

--> i test lighted the grounds going into the ECM for the injectors. which are labeled d14 and c15 for INJ 2 and d16 and d15 for INJ 1. DID NOT GROUND THE TEST LIGHT.

--> i checked outbound grounds on ECM corresponding to A12, D1, and D6. Succesful grounds from a hot test light.

--> i traced the injectors wires all the way from the injector harness to the computer. no cuts. no shorts.

-->i have tried two different computers. no difference.

--> i have tried two different ignition modules. no difference.

other areas of concern which i plan to address for this swap but should not effect injectors.
--> not sure if i am using a 305 or 350 knock sensor. i had a few kicking around the shop. shouldn't effect fuel?
--> i just read the pinned post on this page and for tbi swap it says i need to change the ESC. i have not done that but i can. not sure if this effects fuel inj?
--> currently have 305 injectors on my tbi unit, planning to change to caprices injectors. even though they are 305 injectors the computer does not know that and they should still be spraying.

ECM diagram for an 1988

image url

highlighted INJ harness in yellow and ECM grounds in green

picture share

my poor harness pulled apart to check for shorts or cuts in harness.

photo uploading

Tuned Performance

iTrader: (92)

The power comes through c100 , if there's power at the fuse box check c100 to see if there is a terminal issue or the power wire is hooked up incorrectly.

CamaroHotRod

you mean c10?

DynoDave43

iTrader: (11)

I think C100 is the large multi-pin connector that passes through the front-of-dash (firewall).

Tuned Performance

iTrader: (92)

C100 is next to the master cylinder in the bulkhead .
http://www.austinthirdgen.org/index.php?pid=19

CamaroHotRod

okay c100 is the connector from the firewall to the interior. i see that now. but which wire on that is the ones i need to test for the injectors what locations?

i see on austin third gen websites has diagrams for c100 but not for 1988 only 87 and 89... which diagram should i use?

also i noticed both 87 and 89 c100 diagrams are for TPI cars not TBI

Tuned Performance

iTrader: (92)

Thanks johninri
http://berlinetta.info/C100.htm
Sorry, Looks like you need to look at c207 if that existed on your car.

CamaroHotRod

whats c201

Tuned Performance

iTrader: (92)

C 207 is the circuit number. C is a connecter, it was next to the ECM.
https://www.thirdgen.org/forums/electronics/698283-crank-fuse-keeps-poping.html

CamaroHotRod

I'm confused with all this c207 c201 c100 stuff.

Schurkey

Trace the injector + wires again. If the fuses are hot and good, there must be power to the injectors unless the harness is faulty.

Injectors are "hot" with key "on". ECM controls the ground for the injectors, causing them to spray fuel. ECM controls ground based on signal from distributor that distributor is turning. You won't have ground to the injectors without cranking the engine, or supplying a cranking signal as if the distributor was turning.

Power failure to injectors may not be the only problem, but it's the primary problem.

CamaroHotRod

when i test lighted the injector harness i did it while key in on position and while cranking. both came back negative.

also what other problems are you concerned about?

Schurkey

I'm looking at the wiring diagram you supplied. There's nothing between the Injector #1 and #2 fuses and the molded connectors that plug into the injectors, except the wires, although there must be some kind of splice where the wires change color.

At any rate, if the fuses have power and the injectors don't...that's the FIRST thing to fix. Did you test both sides of the fuses? Popped fuses will have power...on the input side. You need to assure that there's power THROUGH the fuse; and after that there should be power through the two wires to the two injector connectors.

Nothing until you get power to the injectors. After that...we'll see what happens.

CamaroHotRod

both input and output fuses are hot.. .. i am somewhat mechanically perceptive to automobiles diagonstics.

Tuned Performance

iTrader: (92)

Plain and simple if you cant find the wire going from the fuse box to the injectors, run a new one and continue on.

CamaroHotRod

i ran a new wire from output on fuse to injector . the injector does still not spray fuel.
i put a test light on negative wire of injector. with a new hot wire from fuse to injector, the injector will only spray for a quick second when i prob the ground with the test light. meaning the injector is only grounding though my test light. not through the ecm.

also i have concern that the factory hot wire for the injectors come from the ecm. not the fuse panel. so I'm bypassing the ecm when i run my own wire to it.

Tuned Performance

iTrader: (92)

The other thing to look at now is the icm wire esp the purple/black stripe wire.this is the distributor reference signal to the ECM. It tells the ECM when to fire the injectors.

CamaroHotRod

I Did not locate a purple/blk wire from distributor to ecm. I did however locate a purple/white wire from distributor . Do I need to see if that's hot?

Schurkey

Test for spark at the big coil wire while cranking.
Spark = ECM is getting crank signal. It is triggering the coil to make spark, it should be triggering the ground for the injectors to spray fuel. Failure MIGHT still be in the ECM, but more likely in the harness from fuel injector to ECM.

No spark = ECM not getting crank signal. Failure might be from pickup coil in distributor to distributor module to harness to ECM.

Considering that the + side of the injector harness is open, it's not a big stretch to think that the ground side might be open, too. Probably in the same physical place--the harness got pinched or cut and the wires don't connect any more. That's not guaranteed, but it's the most likely of several potential failures.

CamaroHotRod

1. i have spark.

2. i don't think failure is in ECM as i tried two different ECMs from running driving vehicles.

3. i un-loomed my whole entire harness for the injectors. i visibly see the wires all the way from the injectors to the computers. no cuts no pinches no shorts. the only place i can't see the wires is where they go through the plastic waterproof connecter at the passenger side kick panel. where the harness comes into the chassis and into the interior of car. assuming that the wires are not damaged in there. the are wires not damaged.

what would you recommend now?

Schurkey

ECM knows the engine is being cranked. It should be supplying pulsed ground to the fuel injectors. Since you now have power to the injectors, pulsed ground should make them spray fuel. Since you have no fuel spray, apparently there's a problem between the ECM and the injector.

Seems reasonable as long as the ECMs would be used with the wiring harness you have.

Now we have to test what you can't see.

Grab your ohmmeter, set on low-ohms scale (the reading should be less than a couple of ohms if the wires are good.) You will probably need to extend one test lead with some generic primary wire so the lead will reach to the fuel injector wire under the hood, while you work inside the car at the ECM end--use however much primary wire (12- 14- or 16-gauge) you need, but then zero your meter with the extension in place so the ohmmeter reading isn't thrown off by all the extra wire in the test-lead circuit.

Connect to the fuel injector negative wires one at a time--according to your diagram, one will be dark blue at the fuel injector end, which eventually splices to a pair of light blue wires at ECM terminal connector C2, slots D15 and D16. Check from dark blue fuel injector end to each of the light blue wires at the ECM end.

Do the same for the other injector--dark green wire at the injector, which splices to two light green wires that enter the ECM connector C2, slots D14 and C15. Check each light green wire.



My hunch is that you'll have "open" indications for both wires, meaning that even if the ECM is grounding the wire at ECM connector C2, the fuel injector isn't being grounded 'cause the wires are broken. The diagram you provided does not show bulkhead connectors, or any other designed-in wire couplings in the circuit, but IF (big IF) there's a connector in the circuit that isn't shown, and your harness is mis-matched, that could be the problem.

As said, you'd expect no more than a couple of ohms, less is better. I'd love to see less than one ohm. An open reading means the wires are broken--or you're measuring the wrong wire.

Schurkey

Does the pickup-truck computer use the same pinout strategy as the Camaro harness? GM does a lot of parts-bin engineering; they're pretty good about not changing something unless they have to--unlike, for example, the Japanese, or Ford who seem to think that "we've already paid the engineers, we might as well have them change some things".

Still, it would be worth confirming that the '88 C1500 computer is compatible with the '88 F-body harness, and that the '88 F harness will work with '85 F bulkhead connectors .

CamaroHotRod

I am also using the interior/body harness from the same 1988 F body Camaro. So I know the bulkhead connecter pins line up.


and my worries for the '88 c1500 computer being different is a concern, however even when I plug the old 305 computer back in. that was originally mated with the '88 harness and the '88 body harness and ran in a car last month. I am still having the same fuel injection problems.

Schurkey

Alright. That's somewhat reassuring.

At this point, we know both + wires to the injectors don't have continuity, because the fuses have power but the injectors didn't, and both - wires to the injectors are probably broken somewhere, too. Did you ever check for continuity using the ohmmeter?

You ran a jumper wire to supply the injectors with power, and they spray when you ground them with your test light--so the injectors should be OK.

Tuned Performance

iTrader: (92)

Just wondering why you are using a 1227727 ECM, do you have a truck 700r4 vss ?
A 1227846 with a mechanical speedometer and optical vss may have been a better choice !

CamaroHotRod

I plan on spending some time out in the shop later this afternoon with a ohmmeter. so I will get back to you later with some information.


the injectors did give a short quick spray when I jumped them. so I believe they do work. even if they don't work I am not concerned about it at this point I am concerned with just getting power and ground to them. I can worry about swapping the injectors out later.





the 700r4 is from the same 88 c1500 truck the computer came from. I am not using not the electrical vss it came with because I plan on hooking up a 5 inch auto meter mechanical speedo. however that's a story for a another day. lets get this car running first!!

couchmotors

check your ignition module under the cap it also gives and the coil (copper winding) under the rotor cap that is what tells the injector to fire because there is no cam or crank sensor.

Tuned Performance

iTrader: (92)

Now that you have verified the distributor reference line, power and grinds of the ECM and injectors. Have you verified fuel pressure or even used a noid light. Just a FYI you will need to manually lockup your tcc with a toggle switch or finish the wiring of the drac to control the iac, tcc and fueling as well as code 24.

CamaroHotRod

i have tried two different ignition modules. no change.

whats code 24. and whats drac. and what does that have to do with my injectors not getting power by the ecm.

Schurkey

The injectors get power through the fuses you tested and said were "live". They get ground through the ECM.

couchmotors

did check continuity on the coil winding under the rotor cap. I had one that corroded and it was not giving the signal to the ignition module. its what plugs in the module under the cap check it for continuity if you don't get it its fried. my 89 rs with a 305 did this and it took me 4 days to hunt it down.

couchmotors

1

Schurkey

How bad can his pickup coil be if he has spark?

I admit that I have seen "weak" pickup coils, but that's more due to magnet problems than broken-wire problems, and so it doesn't show up in an ohmmeter/resistance test.

Tuned Performance

iTrader: (92)

A icm could be bad have spark but no injector pulse. The only way to test is with a noid light !

Brandonjsims

I am having the exact same problems! I have power to the Injectors just no pulse. I will check my ground wires today/ run a jumper wire to make sure. Also When I changed out my cap and rotor I noticed that the wires connecting to the ICM were exposed and the connector was broken but the wires were still attached. Would this cause the injectors not to fire? Also would I have to replace the entire distributor to replace those wires and connector to the ICM?

Tuned Performance

iTrader: (92)

If your asking about the external side of the I me you can repair it with a new Delphi or Packard weather proof connected. The wires on the inside are the pickup coil witch can be easily replaced but you will need to remove and disassemble the distributor.

Brandonjsims

I went ahead and replaced the distributor. Found out the Problem!!! Oreilly's gave me an ECM for a TPI car not a TBI, so after ordering it THREE times they finally got it right. Then I ordered a Prom that deleted the Vats. That got the car running. Then I found out the person before me decided to take a bunch of parts off and I have been replacing them as I go. Now I just have 2 vacuum lines that need a place to go and it will be done. But for the First time in years this cars went around the block under its own power yesterday, Thanks to all of the Guys on the NTTGA group on Facebook helping me get my vacuum lines right!!!!

DynoDave43

iTrader: (11)

Awesome! Glad you got it figured out.

Brandonjsims

WELL!!! I though I had the problem somewhat solved. But I fired it up last night and it did not do so well at all. I took it for a spin and it wouldn't get over 30mph. The temp also skyrocketed to about 250 in around 6 minutes. I have a new thermostat and Thermostat housing. I had flushed the radiator and put new antifreeze/water mix. Could this be do to the Heater control valve being replaced with a Tee? Just when I thought it was about to be ready for inspection it throws this curve ball at me!!!

DynoDave43

iTrader: (11)

Wow, I'm sorry to hear that. No power and running hot. I doubt the control valve would have anything to do with that. And if it did, it would do it all the time.

Lean can make it run hot, and lack power. Also makes me wonder if your catalytic converter is plugged.

Tuned Performance

iTrader: (92)

Have you pulled the plugs to see if the engine is running lean ?

Brandonjsims

So Sorry Guys I meant Rich!!!!!! I don't know what I was Thinking. and yes I pulled the plugs and checked. Lean LOL!!!! My bad I have had an exhausting last week and weekend. I have noticed a small puff of black smoke when I ran it Saturday. You can smell how rich it is running too. Also Fixed the over heating problem. I didn't put enough water in to fill the reservoir and It was pulling in air from that and not letting it escape so it could cycle through. well at least I hope that is it I didn't run it for very long this weekend. Hope it isn't the water pump.

Tuned Performance

iTrader: (92)

The first thing you may want to invest in is a sub to aldl cable or a older outcome scanner. This way you can see if it's a bad sensor, cts, map, tps or if the O2 is not active and going into closed loop. Using a timing light you can aim it at the injector pod and use it as a stove to see the injector spray to see it they are a nice spray pattern or is there is any dripping in the spray as well.

DynoDave43

iTrader: (11)

I did not know that. I learn something new here each day.

Kalifornia

Ok so what happened was... i took on a half finished project and bit off more than i could chew... its a 83 chevy cabrice CCC 305 well it used to be... its a stand alone tbi 350 now...well its suposed to be...

I have a engine from a 1993 chevy 1500 tbi 350
Computer i have is a 1227747
but harness is a 1989

After reading throu all of this a few times ive come to the conclussions that IM SCREWED... I need sombody willing to make this alot easier for me and kinda dumb it down a bit...
Help my by giving me a detailed list of parts i should use???
Should i go get a 1227846ecm?

m still using the 700r4 from the 83 caprice? No vss
I have some mechanical abillity but im no technition... im looking for somone to be patient with me and dumb it down a little when i ask so i can actually learn somthing

For starts i think i need to just take my losses and get a new harness(if im wrong please speak up). My Current Harness is a 89.... i have NO clue what the computer number was...Somboy has choped both plugs from driver side... both big and small plugs... some wires are used but some like the VSS are completly gone.... l have a list of unused wires from there tomarrow for you... details on my harmess it has a 2 wire oil sender behind dizzy, has 1 wires water temp in side of the head, (2) single wire o2 sensors??? And had the big 3 wire plug for tbs...and what looks to be (2) knock sensor plugs??? Much diffrent than the 93 1227747 harness should have been... but ive made most changes to make it work now unfortunatly...anyone care to guess what harness i have??? I have tons of pics if it helps

Ive got a TON of pics and can supply anything needed and can even do this throu text or over the phone.... thank you in advance anyone willing to help me

I want to used a factory harness to challenge myself but ill buy a prom,ecm,altenator adapter, and whatever i have to... please i just need somone to help me in the mess