stalling out and loss of power
05-20-2014, 07:56 PM
#1
Advanced
Thread Starter
stalling out and loss of power
Hey guys. I am having a problem with my 1988 CORVETTE convertible. For the last few days I have been noticing a loss in power when I step on the gas and often at times when I do step on the gas or am at a light idling the car seems to stall out a little. I started putting premium gas in the car a couple of weeks ago and I dont know what kind of gas the previous owner put in the car for 25 years would that have made a difference or cause the car to stall?? I also noticed that on the dash my average miles per gallong gauge went from about 15 to 8 in the last couple of days.what could be the cause of all this??? could it be that maybe I need to change the spark plugs??? please give me suggestions or ideas on how to rectify this problem thanks
05-20-2014, 08:54 PM
#2
Melting Slicks
Re the stalling,
Fuel pressure check that at the TPI fuel injector rail, it has a small cap that you can remove and fit a fuel pressure gauge/hose to that 1/4 fitting. Turn the ignition on and the fuel pump will prime a few seconds, then start the car and note the fuel pressure (should be around 38 psi)
If it is well below you may have a fuel leak at the pulsator connected to the fuel pump in the tank, or injector leaking.
Check your engine oil for any signs of fuel, a leaking fuel pressure diaphragm or leaking injectors not shutting off can result in fuel filling the sump. (via the vacuum hose on fuel pressure regulator or leaking injectors)
I recommend checking the EGR exhaust gas recirculation valve under the plenum and check it seats correctly, if it doesnt that can cause stalling at idle and rough idle.
Check your spark plug leads (with multimeter and check all have roughly the same resistance) they tend to fail near the spark plug with the heat from the exhaust.
A leaking injector can also cause stalling with unbalanced cylinders, the oxygen sensor may pick it up and explain both.
Re the loss of power. Check your TPS (throttle position sensor)
The top and middle wires (you can push multimeter probes down into the connector) following the wires or buy a connector lead for that purpose.
It should have 0.54 volts dc at idle or with ignition on, it doesnt matter too much if its up to 0.60v dc some set the TPS to that for better throttle responce.
Then check with just ignition on no need to start car that the voltage goes from 0.54 volts dc up to 4 volts dc at full throttle.
Even 3.5 volts dc is sufficient, check the connection is good.
Regular or premium will work however stay away from the ethanol blend fuels they will cause damage to the standard injectors.
If you need new injectors call John at Fuel Injector Connection (scroll down the list on the left of the page) He can get you some nice new or reconditioned injectors at a resonable price. A lot from this forum are using his Bosh 111 injectors.
Fuel pressure check that at the TPI fuel injector rail, it has a small cap that you can remove and fit a fuel pressure gauge/hose to that 1/4 fitting. Turn the ignition on and the fuel pump will prime a few seconds, then start the car and note the fuel pressure (should be around 38 psi)
If it is well below you may have a fuel leak at the pulsator connected to the fuel pump in the tank, or injector leaking.
Check your engine oil for any signs of fuel, a leaking fuel pressure diaphragm or leaking injectors not shutting off can result in fuel filling the sump. (via the vacuum hose on fuel pressure regulator or leaking injectors)
I recommend checking the EGR exhaust gas recirculation valve under the plenum and check it seats correctly, if it doesnt that can cause stalling at idle and rough idle.
Check your spark plug leads (with multimeter and check all have roughly the same resistance) they tend to fail near the spark plug with the heat from the exhaust.
A leaking injector can also cause stalling with unbalanced cylinders, the oxygen sensor may pick it up and explain both.
Re the loss of power. Check your TPS (throttle position sensor)
The top and middle wires (you can push multimeter probes down into the connector) following the wires or buy a connector lead for that purpose.
It should have 0.54 volts dc at idle or with ignition on, it doesnt matter too much if its up to 0.60v dc some set the TPS to that for better throttle responce.
Then check with just ignition on no need to start car that the voltage goes from 0.54 volts dc up to 4 volts dc at full throttle.
Even 3.5 volts dc is sufficient, check the connection is good.
Regular or premium will work however stay away from the ethanol blend fuels they will cause damage to the standard injectors.
If you need new injectors call John at Fuel Injector Connection (scroll down the list on the left of the page) He can get you some nice new or reconditioned injectors at a resonable price. A lot from this forum are using his Bosh 111 injectors.
Last edited by gerardvg; 05-20-2014 at 09:05 PM. Reason: More info
01-26-2015, 12:09 PM
#4
Advanced
Thread Starter
battery
hi guys, I have a quick question today. I stored my 1988 corvette outside last winter and this winter and never took out the battery. Last year I started the car once a month during the winter but had to boost it everytime. This year I am doing the same. I went to try and start the car today by boosting it and the car turned over but did not have enough power to start. I am wanting to buy a new battery for the vette any suggestions on what kind and how much to pay??? thank you..