On a 97 3.3 (with 150K miles) what should the vacuum reading be at idle? It is running at 15" at idle. It is a steady reading. It goes to 0" at full throttle, then to 20" on throttle closing and leveling off at 15" idling.
The fuel pressure is 50 PSI with vacuum hose hooked up and 60 PSI with vacuum hose unhooked. Specs are 46 PSI & 55 PSI. I can put a external vacuum on the fuel regulator and it goes to 46 PSI.
Is the vacuum low enough that it is not allowing the fuel regulator to work?
Kevin
A minimum of 17"
What is the problem with you vehicle??????
Glenn Beasley Chrysler Tech
It will lose power at times. It act like it runs out of gas(or flooding?), but if you push the accelerator all the way to the floor it will take off. It may do this three or four times and then start running perfect. I thought the fuel regulator was acting up, so I unhooked and plugged the vacuum going to it. It acted up a lot more. I thought I would not make it 1 mile from my house, but after the first mile it ran fine. I plugged the vacuum hose back in. I do not know for sure if that caused it to act up. I do not know if the higher fuel pressure caused the problem. At idle the fuel pressure is high. With an external vacuum source the pressure goes back to specs.
If the fuel pressure is high will it cause the engine to run too rich? It seem there is a lot of black soot in the tail pipe. It may be normal.
I do not think the AIC valve is working. When the AC compressor turns on the vacuum drops. I do not see much drop on the dash RPM gauge. Some times it will die at idle. I replaced the AIC valve with no change in problems.
There is your first problem. find out why you dont have much vacuum and you will fix the problem
Thats normal and good pressure, forget about fuel pressure or volume
The map sensor determines the load on the engine ok? The map sensor wants to see at least 17" of vacuum at idle. if it see's this it tells the PCM that we are at idle. If the map sensor see's 15" at idle it now thinks that the engine is under a load. When the engine is under a load you loose vacuum. So now the map sensor tells the PCM to keep the injectors open longer for more fuel to enter the engine to compensate for the load (which there is no load because it is at idle). Go back to basic's, check timing and all the rest of those good things that make an engine run. Does this thing have EGR? what vehicle is this?
Forget fuel pressure, thats all good (assuming you are checking it when the problem is happening and it isnt an intermittent fuel pump problem
You need to find out where your vacuum is going
Glenn Beasley Chrysler Tech
When I started it today the check engine light came on. With the key method I got codes 12 61 55. I had the codes pulled with a Sun meter and got P106. Also it said somthing about the Baro switch. The Sun meter said there was a vacuum of 18 hg at idle. My vacuum gauge must be off.
Kevin
Those numbers aren't any good
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