In the 96 and up (CSFI) systems, it's not uncommon for the regulator to leak inside the intake manifold. It could indicate a bad fuel pressure regulator. Remember that low fuel pressure, does not necessarily indicate a bad fuel pump. The fuel pressure regulator is mounted directly on the fuel injection unit.Įngine running at idle - Pressure should DECREASE by 3 to 10 psi The CMFI system uses a single central fuel injector which feeds each cylinder through six separate tubes and poppit nozzles. In 96 they switched over to the C SFI system. According to my manual, the CMFI (Central Multiport Fuel Injection) system is used on all 4.3L V6 VIN W engines manufactured from 92 to 95.
In case you don't have a repair manual here's some quick specs for you. I would really appreciate any advice that anyone might have regarding this problem.ĭon't forget about the fuel filter, could be clogged. I have doubts about an O2 sensor causing this type of problem with no codes (but I am not a mechanic). I am thinking it may be a dirty throttle body or a bad TPS. I am starting to have doubts about my mechanic. I specifically asked him to check the distributor, coil and spark plug wires (because moisture seems to make it act up). It is not throwing any codes and I have brought the car in a number of times and my mechanic can't find anything wrong. It is the at its worst in the spring (I do not have a heated garage and it gets really cold in Edmonton). After I drive around for 20 minutes or more the problem seems to resolve itself. If I do not drive the van for a few days it gets worse. The hesitation happens when I step on the accelerator the van seems to die and then lurch forward in a stuttering kind of jerky way. At first it only happened in the spring but it has been getting consistently worse. I am having real problems with hesitation. I have a 97 Safari RWD with 200K kilometers on it. By the way, I'm told the van won't run without it being programmed.
Unless you know someone personally at the dealership to help you I wouldn't even go near there with this problem. Of course you'll have to have the new one programmed which should cost around $80. You'll have to take the little panel off the side of your old ECM so you can retrieve the knock sensor for your new computer. You should be able to pick up an unprogrammed ECM at your local parts place.
I guess what happens is that a crack develops in the circuit board inside the unit and then when it gets hot/cold, hot/cold etc etc it starts to cause issues like what you describe. He did however tell me that this was a problem for vehicles with your year model and what you did was the test for that defect. Since the van didn't skip a beat we ruled out the ECM as my problem. (We're talking about the module below the brake master cylinder with 4 cannon plugs coming off towards the front of the vehicle.just making sure) The mechanic took a ball peen hammer and hit the ECM while I had the van running. Anyway I was referred to an experienced mechanic that did exactly what you did. I think it's call the ECM on the wire diagram. When I was originally troublshooting my no start problem I suspected the engine control computer. Reply for the 1996 Safari with the spuuter and misfire.