It seems like I am making quite a bit of threads lately
Anyway I just recently got my car running...well somewhat running
and now I am trying to get it to drive well. I replaced the whole ignition
system and the fuel filter. What the car does is at idle if I hit the pedal quickly
it will stumble before it starts to rev up. I am not sure I would call it a bog...
but it could possibly be. The other problem is when driving I dont have power until about 2-3K rpm. When it hits that mark it starts to accelerate alot better. Any ideas?

 

Mine had almost the same problem, Only the "bog" at a quick start. i took it to a shop and all my belts were REALLY loose. they put new ones on and. it runs fine now. so i dont know if yours is exactly the same problem but its worth a check. only cost me $70 parts and labor

 

I will check but mine is a serpentine so I dont know if it applies lol.

 

I bought a fuel pressure tester today to do a test and here are the number's.
(test was performed with engine off and ignition on)
the fuel pump primed to 44PSI then slowly dropped.
PSI fell to 40 within 25 seconds
PSI fell to 30 1 min after that.
PSI fell to 20 2 mins after that.
I tried pinching off the return line and it didnt make a big difference.

 

I got a 86 IROC with a 87 350 TPI. I had the same issue too. Here is how my issue went away. I bought a set of 22 lb Bosch III injectors and installed a Hypertech 127062 - Hypertech ThermoMaster Computer Chip. I installed both at the same time. I had immediate results. No more sluggish, hesitating acceleration. Also took care of the miss I had. I now experience a good and impressive launch froma dead stop. For me, problem solved.

 

Hmm interesting. I guess if I cant figure it out then I will replace the injectors. I am thinking it is either the Fuel pump or the injectors now.

 

Test out the fuel pressure. Rent a fuel pressure gauge from Autozone and record your results. Connect the gauge, turn the ignition to on, then run and write down the pressure reading. It should saty steady. If it drops relatively fast, then you got a bad Fuel Pressure Regulator. But if stays constant, your good. Now turn on the car with the gauge still conected and now write the pressure agian while on. Then caome bad and type in the readings and other members will help you out. This is how you'll find out if your fuel pump is going bad. Fuel injectors can be tested too but it is not a garentee that they are performing like they are suposed to EVEN if the resistance is within range. Im not certain of the averages but post em here and someone will jump in and let you know what the correct are. I personally would replace the injectors if they are the originals.

 

There are 4 things that can cause you to lose pressure, Regulator, pump, injectors, fuel feed lines.

Prime the system and clamp the feed line and see if it bleeds down if it does, then most likely it is the injectors or regulator. if it doesn't, then it's the pump or the rubber feed line in the tank.

Clamping off the feed and return and losing pressure is most likely an injector(s).

You take the plenum and runners off and lift the fuel rail off and put a pan or rags under it and prime the system to see if any injectors are leaking.

The Pressure should hold steady for at least 30 minutes (that is how long I had my gauge hooked to my car when I was testing it)

 

I was going to suggest a defective EGR if it bogs... but since you mentioned your fuel pressure drops, well I would start there... also make sure your timing is correct...

 

Ok so I put the fuel pressure tester on the car and started it.
It read between 42Psi and 44Psi.
I revved the engine and the pressure climbed a bit
then when I let off the throttle it went down to
36Psi then went back to 42Psi. I advanced the timing a bit
and it seemed to help alot so I need to get my mechanic down here to
set it perfectly on time BUT My pressure is still bleeding off quickly
so I think there is another problem also.

**EDIT**
I started the engine again and it read a steady 38Psi at idle then
when revved when to 48Psi then dropped back down.
Also when you rev it it backfires or "pops" as the RPMs wind down.

 

You can set the timing yourself. Its easy. Disconnect the EST pigtail, plug up the timing gun, turn on car, shoot and turn the dizzy to achieve 6*. Turn off car, reconnect the EST pigtail, Disconnect battery for 5 minutes, tighten dizzy down, reconnect the battery, remove the Timing gun, and your good to go. The ECM and the ESM will take care of the timing advance/ retard aswell as other sensors such as the knock sensor (if you have engine knock).

 

I would do that if I had a timing light lol.
My mechanic is an old friend of mine and will do it for free so...yeah.
I need to look in the book for the EST thing though because I dont know
what that is...

 

Here is a vid I took... It does not really show the problem very well but maybe one of you can get something out of it. BTW the car was already warm when I took this
http://s417.photobucket.com/albums/p...=Video0003.flv

 

I had almost the same issue. Well my problem is no longer with me. Im sure the engine is getting enough fuel, but dont quote me on that.. In your case, you may have to go through trial and error. I listed (PROM CHip and Fuel Injectors. What I did and I solved my issues. You could be getting a bad spark or retarded or advanced spark. I would first do the timing at 6* with the EST wire disconnected. If adjusting the timing doesnt work, then I would start replacing with new parts starting with the most obvious , to the least obvious. Example, pick up coil, ESC module, new dizzy cap, rotor, plug wires, spark plugs, fuel injectors, ICM, PROC Chip, or new ECM, fuel pressure regulator, and finally, the fuel pump. To replace the fuel pump is a pain. You must raise the Camaro up atleast 2-3 feet up in the air and let the rear axle hang low enough to drop the tank.

 

Alright I am going to order the fuel injectors this week hoping it solves the problem.
Just to add a little more detail... The car responds quickly when you just start the car with the engine cold but almost instantly afterward it starts hesitating. Also the car is not easy to start it takes 10 seconds of cranking and it will start briefly and immediately shut off unless you give it gas. When you give it gas the RPMs go up to the normal range and it will idle like it should.

 

. Lets see what happens when you install the new injectors. Then we'll continue from there on. Look at it like this, sooner or later you where going to need to replace the OEM injectors.

 

Ok...soo Since my car has been sitting for a while is there anything I should clean or replace while I have the plenum off?

 

make sure the EGR ports are clean and clear ...

 

Buy a new Fuel Pressure Regulator. If you got money, either buy Bosch III injectors, or have your current ones serviced with ultra sonic cleaning. It'll be wise if you buy new upper intake runner gaskets.

 

how did things turn out?

 

Nothing yet... Financial problems are keeping me from going any further ATM but I am going to go sell some stuff so hopefully then.
Is Southbay injectors a good website? The injectors are only 135 or something like that so its the cheapest I have seen. BTW what gaskets
am I going to need for the injector swap?

 

south bay is great bought mine from there. you will need upper and lower runner gaskets and a fuel rail oring kit to rebuild the fuel rail. I thought i could get away without fuel rail orings, and i couldnt. the only place leaking after injector swap was fuel rail. learn from my mistake buy the oring kit.

 

I HAVE THE SAME PROBLEM CHANGED THE INJECTORS ALL IGNITION PARTS WIRES PLUGS SENSORS BUT WHEN I AM ONTHE HIGHWAY THE CAR WONT GO ANY FASTER EVEN WITHTHE GAS PEDAL TO THE FLOOR SO I BOUGHT A NEW DELPHI OEM FUEL PUMP. LET ME KNOW HOW IT WORKS OUT WHEN YOU CHANGE FUEL PUMP, OR IF I CHANGE MINE BEFORE YOU DO I WILL LET YOU KNOW.

 

Bought my injectors today so we will see if it makes the problem go away.
I plan to clean the EGR and put in a new regulator...anything else?

 

how did things turn out? it kind of sounds like your catalytic (sp?) converter might be clogged.

 

another possibility is the TPS is defective. the TPS is like an electronic accelerator pump from the old carb days, when you open the throttle, the ECM sees a rapid voltage increase and holds the injectors open a little longer to richen the mixture. if the TPS is bad and not sending a good signal when pressing the pedal the ECM will not hold the injectors open long enough to richen the mixture enough to overcome the sudden rush of air into the engine.

 

Ok I will replace it before I change out injectors just to make sure its not that. Anyone know a part number for it?

 

Dont need a part number for it because there is a couple different brands found at AZ, NAPA, and Pep Boys. Just tell em what year make and engine style and they'll give you your options. If you really want brand name and quality, go to the dealer. May be more expensive but it is well worth it in the long run since it is made by GM.

 

NEW MAGNA FLO CONVERTER I ONLY HAVE ONE I STILL DIDNT CHANGE OUT FUEL PUMP IWILL TRY THIS WEEK.

 

Im having a similar problem. Car runs great at Idle and then when driving it runs like crap feels like theres no power. It backfires on decceleration, im thinking it could be injectors or timing. I have new sensors TPS, IAC, CTS, O2. How do you test the injectors? and also i dont have the original timing tab from the 87 305 tpi. I have it from the 90 TBI. before my TBI to TPI change.

 

OOOOHHH. Injectors= Do a search (https://www.thirdgen.org/forums/search.php) for "fuel injector resistance"

As for the timing tab, you may have to look for an other IROC and do some precise measurments of the general location. Or you can read this post... https://www.thirdgen.org/forums/tech...-find-tdc.html. But remember, our TPI systems are suppose to be set at 6* advanced with the EST wire disconnected. Once you have 6* advanced, reconnect EST wire and the ECM will control the spark via ESC Module, Knock Sensor and so on. But you cant find 6* because you dont have a tab. So your best bet is to hit the junk yard and get a timing chain cover from a IROC. So bro. Im sure there is a way to get the job done because there is aftermarket covers that have a adjusting tab. Good luck man.

 

thank you, i do have an aftermarket tab that was in the same location as the one on my TBI on my 90. But i dont know about the 87 Iroc Engine

 

Almost all engines are the same depending on its design. Example, my engine block can be used on vehicles that range from a number of years and models. What makes the difference is the intake and fuel system setup. Other diiferences include location of the oil dipstick, 1 or 2 piece rear main seal, and the rotating system (crank, pistons, rods, bearings and most important, the camshaft).
Here is the specs on my 350 block

14093638 1987-95 350 2/4(MAINS) Roller or flat tappet cam one-piece rear seal

To verify your block via casting numbers, go here
http://www.chevy-camaro.com/chevy-ca...gine-codes.asp

As for your timing tab, I have no clue if the TBI is the same as the TPI. But you know what, it should be the same because a 86 305 eTPI engine can be used on a 305 92 RS, just different intake and fuel system.

 

I checked my fuel pressure, and I have 47psi with the key on and when i start it. it runs about 42psi and if i accelerate it jumps to 45 for a second then falls to 42psi and holds there. I dont think there is a problem with fuel pressure

 

my injectors come today so I guess we will be seeing if they are the problem soon.

 

Don't buy a new one until you test yours, it might only need an adjustment. I think there's a TPS adjustment tech article here, all you need is a couple paperclips and a digital voltmeter and ten minutes.

 

After I get the injectors in I will look into that. Thanks.

 

Pleasee keep us posted on what the injectors did for you. If they solved your problem or not

 

Sure thing. I am picking up a timing gun from my uncle tomorrow so...tomorrow is the moment of truth.

 

Just to clarify before I go screwing something up... Do these injectors need the clips put on them or are they press fit? they look different from the ones in the tech article.

Bosch IIIs

 

No they dont need the clips. They are suspended in between the rail and the intake. I have the older version as in the lower end has a double o-ring. I believe S.B. and the other vendor came up with a new design that is now a perfect fit for our TPI. But take a close look at the upper neck of the injector, there is no groove that would allow you to slip on the spinning locking piece. So no, you dont need the little locks. Dont get discouraged about the injectors. I got a set of 21 lbs Bosch III's for my 350 TPI and they work beautiful. Have fun.

 

No update today.... I cant find my damn keys...

 

 

X10000 and you know how I feel
I cant believe I still cant find em.

 

You still cant find em? I really hope you find your keys. Use this situation as a reason to have spare keys laying around. You didnt lock em in the Camaro?

 

No I dont keep the doors locked because there is nothing to steal on the inside... I still cant find the damn keys... It was a vats key too.

 

find them yet?

 

No... As of right now I am looking for a replacement key and cylinder -_-

 

DAAAAAAMMMMMBBBBBB! Wow bro. You absolutely cant remember what you did wit em?

 

Yeah...I tore this whole dang... house apart and I cant find the damn things...