SoCo80p

iTrader: (5)

i have a 87' s10 2.8 tbi. The engine has ran like a top since i got it. But one day i go to start it and it runs like complete crap and smoking up a storm of raw fuel. With the engine running i look under the hood and notice the left injector is spraying full blast while the right is doing the correct pulsing. I switch sides with the injectors and same thing happens, fine on the right, full blast on the left. I just went and got a new computer today to see what happens and the same thing. What could be the problem??

Persanity

personaly, id return the computer and get new fuel injectors for your tbi setup and see if that fixes it

Naft

he already proved it wasnt the individual injector.

i would definitly look at wiring before replacing the ecm, in a car this old i would consider wiring to be the main culprit of any problem. its hands down the cheapest thing to fix on any car, although probably one of the biggest pains too.

2_point8_boy

Now, did you actually switch the injectors, or just the harness on the the injectors.

I bet this thread gets locked...there is zero third-gen related text.

Persanity

well in his sig it says he has a camaro or firebird, so its a thirdgen owner asking about another vechile he/she owns with the same engine, itd be pretty screwed up to lock the thread.

Naft

well, technically a 2nd gen + 87 car with a 2.8 does not = thirdgen, so i can definitly see it getting locked.

but hopefully we can get this fixed before that happens.

grab your multimeter and check out the wiring for shorts or opens, or if its just the one side, see if you cant switch the wiring and see if its the wires.

unless as 2.8 suggested thats what you already did, then it would have to be the injector on that side.

SoCo80p

iTrader: (5)

yes i do understand this is not 100% third gen related, it is the same engine used in many GM cars in the 3rd gen era and i've made over 1,000 posts over the past 4+ years helping out when i can, so i think one simple post isn't going to be that big of a deal

But anyhow like mentioned i swapped injectors from one side to the other and still did the heavy spray just on the left side, the injector also dripps when the key is put in the on position. I did try a new injector, it did stop the dripping when it was off, but still did the heavy spraying while running, I just don't see what could be causing the car to give a full blast signal just to that one side

2_point8_boy

If there are 2 injectors drivers in that ECM then the circuit for the left one has wiring chafed through somwhere and it's grounding out against the chassis or motor.

The injectors are always powered and the ECM supplies a ground to fire them. WHen you get a ground somewhere that isn't computer controlled anymore, the injector just stays open all the time, spewing forth unwanted fuel.

The leaky injector is obviously bad, so it needs to be replaced regardless of anything else, unless you don't mind a leaky injector. But to solve the problem, you'll have to find where the injector return wire to the ECM is grounding.

Didn't mean to ruffle feathers on the lock-out thought, just preparing you. I don't mind the questions, but it is non-thirdgen related since no third gen ever had a 2.8L TBI from the factory. I don't think it will matter that the engine was used during the 3rd gen era or the number of posts you've made, because if that was the case then I could post questions about a 3.8L. Just be prepared...

SoCo80p

iTrader: (5)

I did follow the wires as far as i could (not all the way) and they looked ok, i did notice every time the engine does start the engine light comes on and pulls code 34 which i think is low map sensor reading? i don't know if that would be causing the problem

2_point8_boy

The MAP sensor code is seperate from the injector being on all the time. No question that there is a short to ground in the wire back to the ECM.

Here's what you do to be sure, take a DVOM and set it to test for continuity. go from the ground side of the injector to any good ground on the engine/chassis/battery post, wherever the DVOM leads reach. If there's continuity with the engine not running, you know that there's a ground somewhere before the ECM, and there shouldn't be.

TechSmurf

A: He's a 2nd gen owner, not a thirdgen owner. Nice observation skills.
B: When's the last time you saw a TBI V6 in a thirdgen?
C: It's perfectly legit to lock this thread, but in spite of your great efforts to annoy me, I'm not going to.

I would suggest asking the TBI board in the future regarding fuel system specific questions, though, TempesT68.

SoCo80p

iTrader: (5)

Ok i went outside with my digital multimeter and set it to the omega setting on the symbol that looks like a sideways line with a triangle and a vertical line on it (i think thats the continuity) i put the positive on one side of the injector connector and the negative to the battery ground, i was getting nothing, on the other it will start off at .500 or so, then rapidly climb up to about 1.600 then nothing for a few seconds then it would do it agian. (this was with the key in the on position) it was doing this on both the left and right injector connectors. i then put the + on one port on the connector and - on the other and got about .553 steady on the left and .563 on the right (on the 20k setting). in the on position bothe gave the infinity reading.