QuestionQUESTION: Hi Howard,
This a follow up from before. I replaced the right sending unit(it works now. I had several problems, repalced the left tank (had hole) replaced the left return valve (it did not work) replaced the changover valve now all that works correctly. After doing this it now dies after it get warms when you try to give it fuel to go. Acts like it's not getting fuel. What did I do wrong? It ran fine before the replacements it just leaked fuel and used only the left tank.
ANSWER: Remove the air filter can and turn on the ignition and reach in the front of the air flow meter and open the flap and you can hear the fuel pump run and you can hear the fuel going through the engine fuel rail and then have some one either hold the flap open or put something in to hold it open and go back and open the gas cap and with a flash light look down into the tank that the switch is set to and see the fuel being returned to that tank. Then switch to the other tank and go look in that cap to see if the fuel is being returned there. This is a test of the switching valve system.
AFTER you have done that and don't skip any of it. You now need a fuel pressure gauge to test fuel pressure. 32 PSI running and 42 PSI pump running but not the engine or with vacuum pipe removed from regulator.
If all that is correct you need to start testing the coolant sensor, air flow meter and manifold vacuum. If you don't have the specs let me know.
Let me know up to that point.
Howard
---------- FOLLOW-UP ----------
QUESTION: Hi Howard,
Everything seems to be working now except, when using the right tank it runs for a few minutes then starts to run bad and will not accept fuel. If you run just on the left tank it usually does just fine. From the right tank it acts like it runs out of fuel. I added a clear filter at the filter and it does not run out of fuel there. It is something after the filter and only when using the right tank. Could it be the air vent and how do I check that? It does have a suction when you open the cap. I see the hose coming from the cap area but don't know where they go from there.
Thanks
Boyce
ANSWER: Boyce, you are in danger! where did you find a clear filter that can stand 45 PSI? None that I know of!!! If you are checking fuel supply it is no use looking at a clear filter unless you found one with a flow meter in it (never happen)
First check to see that the switching valve is working. It is activated only when using the right tank. If the valve "Clicks" when activated go up front. To check fuel flow on the right tank open the filler cap and turn on the ignition and have someone open the air flap in the air flow meter and watch for fuel to return to the tank. If there is none move to the next test point. The fuel line at the fuel rail. Remove it and put it in a can or jar and open the air flow meter flap just for a second. If none, go to the fuel filter and remove the OUTLET line and put it in a can or jar and have someone open the flap for just a moment.
Howard
---------- FOLLOW-UP ----------
QUESTION: Hi Howard,
When the engine gets warm it starts cuting out, each time you press the throttle it acts like it's not getting fuel. If you turn off the engine and restart, it works fine for a few minutes then starts stalling again. Sometimes it runs for miles and sometimes a short time.
AnswerHi Boyce,
You need to put a fuel pressure gauge on a "T" fitting in the fuel line just where it meets the fuel rail and be sure to put a long hose so you can run the hose out from under the hood and put the gauge under a wiper arm so you can monitor fuel pressure as you drive. (Be sure to use fuel injection hose and clamps at every joint and use a metal "T" fitting.
Also, you should put a vacuum gauge on the intake manifold and run it out to the other wiper arm.
Now drive the car and note both gages and what the readings are under different driving conditions.
Some fuel injection gauges are expensive but I use a industrial 0 to 100 PSI gauge which was not expensive and have used it for many years. Vacuum gauges are not expensive anywhere.
Let me know the readings under what conditions you found.
Howard
