I have a 1990 Aerostar with 160,000 miles on it. I posted a thread in the fuel injection section about the problems i've been having. My main question is what would cause this van to shoot raw fuel out the exhaust pipe? Thanks for any help on this subject.

 

Might be a leaking fuel pressure regulator or injector. Run it for 30 seconds, shut it off & remove the vacuum hose from the FPR it should be dry. If it is, put a fuel pressure gauge on it & see if it holds pressure.

 

Thanks 87XLT. I don't know if you read my other thread or not but this van has been doing some funny things for awhile. I replaced the fuel pressure regulator 2 weeks ago. That's when I started noticing the gas problem. I would really appreciate it if you could read the thread in the fuel injection area and see what you think. In the mean time I will go get a fuel pressure gauge and see what it reads. Thanks again for your time.

 

If key on engine off pressure doesnt hold at 40 PSI, i'd guess a leaking injector & pull the plugs to find which one. Will check out your other thread

 

There are a few things that could cause excess gas, bad FPR-look for gas in the vacuum line, Leaking injector(s)-check the fuel pressure bleed down, bad O2-check for codes, cylinder(s) not firing-check for spark at each cylinder and run compression test.

 

Thanks for the info 87XLT and KenOO. When the vacuum is pulled off there is no gas in it. Not sure if there is any relevence here but when the van is running if I pull the vacuum line off it does not change a thing. I've got alot to learn about fuel injection but am making progress with the help of people like you. Thanks alot.

 

Well at this point, it's obvious that you're running too rich, so a small vacuum leak is not going to make the engine run much differently.

If you suspect the regulator, you want to install a fuel pressure guage and check the pressure changes with and without the vacuum line, with the engine running at idle. If the regulator is working, you should have about 40 psi at idle with the vacuum line in place, and the pressure should jump up a little when you remove the vacuum line. If you can also install a vacuum guage to the manifold, you should see an equivalent increase in fuel pressure by the same amount of manifold vacuum when you remove the vacuum line from the regulator. Vacuum guages usually read in inches of mercury, and a properly idling engine will pull 14 to 18 inches of mercury at idle, which is about 7 to 9 PSI.

The other possibilities have been mentioned by others; faulty sensors like the exhaust gas oxygen sensors and mass air flow sensors are the most likely suspects. Further down would be the temperature sensors. Then it is possible to have a leaky fuel injector.

If you run a self-test on the EEC, you can start getting an idea. Unfortunately, a lot of the running tests use the EGO sensors to check for responses from test procedures, so one of them failed, the tests will point out all sorts of faults.

good luck

 

Thanks again guys. Ok, I had a couple of hours last night so I pulled the plugs out to check them. All were dry except the hardest one to get to. It was pretty corroded. They all had to be regapped because they were open way to wide. I didn't change them because they were bought last year. Anyway. I reset them and put them back in. That helped alot. It don't boug out like it was doing, all though it didn't stop it completely from doing it, but it's better. It idle's alot better know too. But now it's smoking and still shooting gas out the pipe. Haven't had a chance yet to put a pressure gauge on it. I will try and do that this evening when I get home. Thanks for the input.

 

Ok, here's an update. I went to the parts store Monday to try and get some advice on what to try next. I had come to the conclusion that it was either the throttle position sensor or the air bypass valve. The guy said to take them off the van and bring them in, he could check them off the vehicle. Got them off and took them in to the store and they said the tps was ok but the air bypass vavle was bad. I bought a new one and came home and put it on and still the same crap. At this point it was not driveable. Next step was to change the plugs and wires, which is what I did and vola, it run like brand new. That was Monday. I took it out this morning(Thursday) for a drive and when I got close to home it started doing the same crap again. I did manage to make it up the drive though. What in the world could be going on with this van? I haven't pulled any of the new plugs to see if any were fouled but the old ones were not that bad. Any ideas is greatly appreciated. Thanks

 

After watching this thread......It seems to me that what it is doing is not firing on all the cylinders all the time. So it is loading up the cylinder with raw gas & then its being pushed out the exhaust.

So it could be a cracked Distributor cap, bad coil, condenser or a loose wire/plug.

Also check to see if the Distributor is bolted down tight. I had an engine that was giving me all sorts of intermitting problems. Traced it down & found a loose Distributor.

 

Thanks for all the info everyone. I replaced the distributor cap and roter. It has run great for the last couple of days. Funny thing is, and I have posted questions about this before, the gas gauge works and the temp gauge is working again. Not sure of the relationship here but am thankful that it is all working again.

 

This does not seem right to me I can not see a ingnition problem causing so much fuel build up to have liquid fuel coming out of the pipe. Or do you mean it smells like raw fuel? Any way if it was pushing out raw fuel do not be surprised if your converter plugs up. You will know if it does by an extream loss of power. Hope all is good.