mikes89GTA

1989 GTA 5.7 TPI.
I had a starting issue fixed that by replacing the injectors. now having a problem when i get heavy on the trottle it wants to die. The motor bucks almost wants to stall recovers only if i let up on the gas. I have checked the timing several times with no results.
The car will run great as long as i drive normal.

Gregzz4

Check your fuel system from front to back
Sounds like it's starving for gas
Or could be weak spark and you need to check your plugs, wires and dizzy

mikes89GTA

OK had a friend come over and we check the fuel system plenty of pressure approx 42 at idle. Change the plugs .wires with no result did find a bad connection on the MAF and now seems to get some surging when the car is all warmed up.

bcmag

doesnt matter what static pressure is at idle.you need to check it under load to see if pump can keep up w/demand.tape that gauge to the wind shield and go for a ride ...you might be surprised at what you see.

skirkland1980

iTrader: (2)

maybe there is a vacuum leak or egr problem.

ninetyone

iTrader: (2)

Have you checked your knock sensor? Do you have any codes? You can test for a bad knock sensor by putting a resistor in the wire.

mikes89GTA

no have not checked the knock sensor.how can i check that with A resister? But new development while the car is cold starts up idles normal when the temp gauge reads 150/170 degrees the idle starts pulsing from 500rpms to 2000rpms then stalls'

Rockguy

I just wanted to subscribe to this thread. I'll be interested to see the resolution.

Dang just found a button where I can subscribe without posting but, I don't see any way to delete this post

ninetyone

iTrader: (2)

Really sounds like a "starving for fuel issue". How is your fuel filter? When was the last time you replaced it? Do you smell an egg type odor coming from your exhaust? Could be a clogged catalytic converter. I have learned to never rule anything out until you check. Also, did you check for CODES? You really need to check for codes. Also , there is an ignition control module under your distributor cap. When they go bad they usually act up after the car has gotten warmed up. Your car will stall and buck, etc. and cut off. Drive up to your local Auto Zone or parts plus, these stores will usually test them for free. Just be sure to use the special adhesive that helps to keep it free from moisture and heat when you put it back on, ask them they should know. As far as your knock sensor, all you have to do is unplug the harness from the knock sensor, and set your multimeter on ohms (20k) setting on the meter. Then put the red lead into the harness(it is only one wire) and put the black lead against the body of the car. You should have around 4ohms or so, give or take. I had a bad wheel bearing and my knock sensor was pulling timing. So, i just unplugged my knock sensor and put a resistor in the wire. If that knock sensor harness is unplugged without using a resistor, your car will stall and bog and buck, and lose all power. Does your check engine light work?

mikes89GTA

The distributor is new, new cap, wires rotor, I will check the knock sensor
no codes are registered engine light does work.
seems like the fuel sytem is working i did test the rail last weekend and has new injectors installed a week ago 24lb/hr python venoms.
doesn't seem like it is starving for fuel. but prob does need a new filter not sure how old.
new coolant temp sensor yesterday.
and again this is only happening at 150/180 degrees while its cold the car will sit there and roast the tires as soon as it comes up to temp starts acting up.

mikes89GTA

So i go out to move the car into the garage engine light is on throwing a 32 code first time this has happened so i start looking at th egr valve for removal find a loose wire next to the sensor and to get to it i have to pull the TPI off.
well looks like i have some work to do i will let known the results.

ninetyone

iTrader: (2)

Spark and fuel problems are hard to tell apart. I told you that ignition control modules usually act up when the car is warmed up and give you results similar to the problems you are having. Check that too. When you change your fuel filter, make sure you blow through it. You should be able to blow through it like a straw. It should be that free flowing. There is also an Intake air temp sensor on the underside of your plenum near the distributor. If that thing is unplugged it could make it run like crap too. Never ran it with it unplugged.LOL. When you check your knock sensor , make sure you put the positive lead of your multimeter probe deep down inside that knock sensor wire that goes to your ecm and make sure the other side is grounded well. Let me know how it goes. Doubt it is an egr problem, egr turns off at full throttle anyway. Later

mikes89GTA

update i ended up finding a few faulty connections. Knock sensor. temp sensor, Maf is good was sucking in hot engine air causing a fault. still may change it.

so now after fixing theses connections the car does stay running after 150/180 degrees.
also retimed the car while in was acting up. my thought was as it warmed up the timing advanced so anyway i retimed it seems to run better i can atleast drive it. Not sure if i have the timing right the factory sticker if gone and i am having a hard time finding the instructions the haynes manual want you to refer to the factory sticker.

while idle timing mark is right below the indicator (doesn't seem right)
as you raise the rpms the mark go towards tdc about 2 degrees above.
The distrib has been out of the car several times while looking down at the distrib cap #1 wire is just to the right of center.

BUT I am still lacking power between 1000 and about 1500 rpms the car wants to bog down. but while driving seems like the plenty of power.

mikes89GTA

well after finding the wire that was grounding out against the bell housing screwing up MY computer and screwing up my timing. so re taped the wire retimed the car which was alot easier this time.
then went for a ride left a nice double black line in front of the house

THANKS TO EVERYONE THAT HAS RESPONDED>

REMEMBER ALWAYS GO BACK TO THE BASICS

ninetyone

iTrader: (2)

Your stock timing is six degrees BTDC. Before you set your timing ,You need to unplug the connector near the coil , it is probably behind the coil and if i remember correctly it is a brown striped wire going to the connector. You dont want the timing to advance while you set it. So you need to unplug that connector. Also number one on your distributor cap is the one right above the power brake booster hose connection on the plenum.

mikes89GTA

thanks sounds like i have everything in the right place