chevy77

okay i have a 89 tpi 305 in my 77 nova it ran great for awhile now i cant get it to run right ive done small upgrades to the motor bigger throttle body headers no cats cold air intake hypertech chip(came with the motor) air pump delete for some reason i have to run my fuel pressure at about 57psi i know thats too high but if i turn it down the car is not even driveable so obviously its running very rich tries to die on rapid acceleration some black smoke fouled out spark plugs if anyone has any ideas im all ears i cant seem to figure this one out

darbysan

I would check your TPS and O2 sensors, and look for any vacuum leaks. Are you getting any codes?

chevy77

tps is set at .54 no vaccum leaks i switched to a heated 02 sensor and i cant check for codes the connector for that was gone when i bought the motor

darbysan

To do things right, you really need to know what is going on with your engine and ECM. Does the car have the stock donor car harness, or is it something like a painless harness? If you have the stock harness, we can probably walk you through connecting up as SES light, and maybe even wiring in an ALDL connector from a Junk yard so you can get tuning info.

chevy77

yes it does have the original harness but whoever had it before cut a bunch of stuff off and replaced some wires so they are no longer the stock color i did a lot of testing when i originally got it running so im pretty sure theres not any wiring problems but there are a few connectors that go to nothing didnt seem to be a problem the first few years so i didnt worry about them but there is no aldl connector and i have no clue if the wires are even there

darbysan

OK, the harness at the ECM has tow large connectors that plug into the ECM, a white 6-conductor connector that is used to supply power to the injectors, fans and cols start ( this connector may have been bypassed), and a white 14 or 16 pin connector that connects the ECM to the Instrument Panel. If this connector is still there, it is where you can pick up the SES light info and the ALDL info. If it is not there, then we can go directly to the two large connectors on the ECM.

Let me know if you want to go further with this. It will take some effort, but the result should be an ALDL port you can tie into with a laptop, and an SES light you can use as designed.

chevy77

okay i looked at my harness at the ecm to double check (its been a few years since i looked at it) i have two connectors in the ecm but they have a lot more wires than you said and they are both black connectors there is a white connector not plugged in to anything most of the wires on that look broke or cut anyway. the 89 motor was not equipped with the cold start injector so no reason to bypass anything there but yes i would love to have the aldl plug because we have a really nice scanner at work i can use on it and i would like to see whats been goin on in there all these years

darbysan

OK, we can work our way through this if you want. First, the white connector that is not plugged in. Can you count the number of pins, regardless whether it has wires to it or not. I'm looking for a 14 or 16 pin connector. Second, I need to know the colors, in order, of any wires that are still going to the white connector. Third, you'll need to go to the pick and pull and grab an ALDL connector, with as much of the wiring going to it as possible. We can splice this in to the wires on the 16 pin connector.

ninetyone

iTrader: (2)

bad CTS will give you black smoke. Ohm your injectors too.

chevy77

okay did a little work today took the throttle body off cleaned it cleaned the iac valve replaced some vacuum lines i know there were good but i figured id try anyway then i decided to clean the spark plugs since its running so rich and i found something new cylinders 1-7 were black from being rich cylinder 8 was the opposite it was running very lean so i ohm tested the injectors 1-7 got a perfect 16.5 and 8 got a 4.9 so luckily i have an extra tpi setup in the garage so sunday i am putting a good one in hopefully this will solve my problems since the symptoms fit for a bad injector and i already tested and replaced the cts

darbysan after i fix the bad injector i will check the plugs on my ecm i will try to get a pic of them if i can (not very good with the camera) and let you know exactly what i have because i do still want that aldl hooked up

chevy77

this sucks went out to get an injector off the extra setup i had all 8 injectors tested bad ohm tested between 11-12 now i have to get ahold of some money for a whole set it would just be stupid to buy 1 new injector

skibum2100

Good idea buying a whole set. Just because injectors ohm out okay, they may still be leaking. Get some Bosch III's, they are great.

Hope this helps.

chevy77

ya thats my plan but its gonna take me a few days seeing how i dont have $150 just laying around southbay seems to have the best price

fireburdluvr85

just to say this, i got there injectors around a week or two ago and its been a big difference. think i paid 150 delivered. just thought youd like input on the product.

chevy77

ordered my new injectors from southbay the other day still waiting for them to show up so i can put them in

chevy77

finally got my injectors (feels like ive been waiting forever) so im putting them in tomarrow ill let u know how it goes

chevy77

okay so the new injectors are in finally running on all 8 cylinders feels like i got some power back but it still has a hesitation espeacially when cold and still running rich i am about tired of trying to track down this problem i am getting no where with it