Firebird_305

Hi guys! So I just installed my reman bosch injectors for my bird. Went from not going above 1k RPM (which led me to believe it was an injector) to now idling at 4k rpm and when you engage it into any gear it drops to 2k (accept neutral where it goes back to 4k). Can anyone point me in the right direction because I don't know where to go from here.

I am extremely happy that my diagnosis was correct and that the fuel injectors where shot. However I am at a loss as to what would cause the significantly high idle. I check the idle screw and it is the exact same way as our v8 bird. I am thinking it could be something with the computer as the kid who had it before me wanted to turn it into a race car. Though I feel lost

Thanks for any and all help!

Firebird_305

After searching a tad, I should have searched prior I know, I found a few people mention timing. If the timing is off can it cause the engine to idle at higher rpms? I have to follow the wiring because it is a mess and see if anything is messed up. So far 150$ in and would love to keep it at a minimum!

Maverick H1L

iTrader: (8)

Did you reset the ECM by disconnecting the battery after your replaced the injectors?

If that doesn't work, first thing I would do would be to break out a can of starting fluid or something similar and start spraying for a vacuum leak. And then check to make sure that the minimum air rate (airflow through the throttle body with the IAC closed) is set at the recommended air flow rate (by engine speed). for how to set the air bypass screw. Just because it's the same on your V6 as for your V8 doesn't mean it's where it's supposed to be.

Firebird_305

I did not reset the ECM as I didn't know you had to. Well first thing I will do tomorrow morning is disconnect the battery and let sit for a bit. I will be shocked if that does the trick! Though regardless I am happy it runs now!

Thank you!

Maverick H1L

iTrader: (8)

Need to reset the ECM after any repair that can have a major affect on how the engine runs due to the fact that the ECM is in a certain set of tables based on the bad components and will make the good components not work properly. The ECM is reset to where it was when first installed to allow it to adjust to the new parts quicker than it would simply making any number of tiny corrections.

for the idle relearn procedure if the car is an auto. Does not apply to a manual.

Firebird_305

Awesome thank you so much! I've read almost the whole entire haynes repair manual I bought for this car and was still unsure where to start! Time to start the searches and get this puppy on the road. Thank you again for the help!!

Maverick H1L

iTrader: (8)

Haynes is good for 2 things:

Camp fire starter (or charcoal fire starter), and toilet paper. It's so vague it's laughable.

Get a GM service manual, either through CraigsList, eBay, or a closed dealer. You can also look at www.helminc.com , but those will run you in the ballpark of $90.

Firebird_305

Yeah I saw the service manuals. Actually found a few shop manuals for sale too from a local GM mechanic who is long retired. I was going to buy it, 100$, but all of a sudden couldn't afford it because my dirt bike just blew the valves and needs a new piston and ring. So right there is 500$ that I wasn't expecting to spend so that manual will have to wait for a while... The little money I have left is going into this to get it to pass inspection. Just need a few miscellaneous items and such. Well had the battery disconnected for a little while, got anxious, so going out to reconnect it and I guess I'll fire her up!

evilemokid94

iTrader: (6)

wanna hear the results

Firebird_305

Didn't make a difference. Well... it did! It started easier, but still idling at 4000 rpms. I have a friend coming from the parts store to help me with a leak test this afternoon to rule out a vacuum leak. Back to square one...

Maverick H1L

iTrader: (8)

Hold off on looking for the vacuum leak until you have checked the minimum air rate. IIRC, should be around 650-700 RPM. And then you will have to wait a few minutes for the ECM to properly set the IAC where it needs to be.

However, if the ECM sets a code 35 (uncontrollable idle speed), you will need to check for vacuum leaks and a few other things.

Firebird_305

Well I am unsure if this is now my biggest concern. So initially I had to get it running, did the fuel injectors and now it runs. Then the high idle became a concern. I have it up on the lift and just did an oil change and more gas than oil came pouring out. It had a high gas smell. So now I am thinking either blown head gasket or the kid over filled it by a boat load and was the cause of that. I keep thinking I NEED to look at the timing, but I feel like that would be a waste of time (6 hrs) to check it. I see a new gasket behind it which makes me think I should. Any advice?

Maverick H1L

iTrader: (8)

The oil will smell like that if the engine has been cranked and cranked and cranked without running, or if it's flooded so bad that it can't start. Change the oil and worry about the rest later. The gas pooling in the cylinders seeps past the rings into the oil pan.

Firebird_305

Well did the oil change, changed it twice and both times fuel was mixed with it. The idle problem still exists too. Starting to shake my head at this because I am discovering more and more wrong with it. Just trying to get the high idle problem fixed first. That is more of a concern to me than the fuel and oil mixture.

Maverick H1L

iTrader: (8)

Make sure you got the right injectors... The wrong injectors won't flow the way they're supposed to and flood the engine.

Again, check the minimum air rate.

Firebird_305

The injectors were the right ones, I'm positive of it. So I cleaned out the MAP sensor and it started doing a lot better! It would just idle between 800-1500 RPM's (surging). So I replaced the MAP Sensor and it went to 500-1200 RPM's, but still surged. I found another TPS in the car so I swapped it and it fired up immediately and just surged between 800-1500 RPM's. So I thought it was a bad TPS so I bought a new one, put it in, and now it idles at 2,000 RPM's. Still a high idle. I did check the minimum air rate and looked over everything. I believe a sensor has to be bad, but I am really unsure. I am at a loss now because just when I thought I was going in the right direction, I feel like I went backwards.

Open to any advice that might correct this surging problem.
Thanks!

evilemokid94

iTrader: (6)

Might have been done already but since I'm on my phone I'll ask. Have you checked your timing?

Firebird_305

No haven't checked timing. That will be the next thing now... should have done it right off the bat

Maverick H1L

iTrader: (8)

You won't be able to check the timing until you get the idle down. The ignition module acts as advance weights in the older distributors (even with the ECM disconnected from the EST circuit)... As the engine speed increases, so does the spark advance.

:edit: How did you check the minimum air rate? If that was indeed okay, next thing to check is for a vacuum leak, and then the output voltage at the green wire on the MAP.

Firebird_305

I am currently at a loss then. No vac leaks, has new map sensor and tps, new and correct fuel injectors 15#. I am now lost because I don't really know what else could be wrong with it. A friend of mine who use to be a GM Mechanic is looking at it tomorrow. Perhaps he'll know what is wrong with it.

Maverick H1L

iTrader: (8)

Check the output voltage (with the key on) on the MAP and TPS. Check the TPS with the engine not running and the MAP while running. MAP is checked between the green and black wires and the TPS between the blue and black wires.

Firebird_305

Alright I'll check those. With the old MAP it ran much better when it got cleaned out so I thought new MAP would fix it. I'll check it though! Thank you!

Firebird_305

Ok so it was the IAC Valve. Replaced that and it runs like a champ now! Now I have to do some interior work on it to get her going. Thanks for all the help guys!