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96 Eclipse Rs Non-turbo Vacuum problem.

08-21-2010, 05:27 PM
Hey guys im having problems with my eclipse. i put a new engine in and now its trowing codes. the ODB11 says that is a incorrect fuel combustion... fuel pressure regulator isnt getting vacuum to it or something. When i crank it it idles a lil below 1x then it picks up... then it starts to backfire really bad!!!. we got new plugs wires Coil... Somebody told me its not getting vacuum to the regulator.. So if anybody could help me out i would really appreciate it!! im young and trying to learn thats all!!

Thank guys

08-21-2010, 07:15 PM
Welcome to AF.
If the n/t model is anything like the turbo model eclipses, then the vac source should be coming straight from the intake manifold. Check the fuel pressure regulator vac line and see what it connects to and see if there's any cracks in the vac line. Definitely check all your vac lines would be my 1st step.

08-21-2010, 08:43 PM
Ok i checked all of them and i took a fuel pressure check gauge and put it on the regulator to see if any vacuum is getting back there. but gas started coming out so idk what the pressure was back there! what would you try next?

Thank you for the help!

08-21-2010, 09:31 PM
The vac line on the fpr had gas come out of it? Which part did you check here

08-22-2010, 12:52 PM
i took the hose off of the regulator and put my vacuum gauge on the regulator. which is located right above the fuel filter. idk man im confused and dont know what else to do!

08-22-2010, 02:51 PM
You put it on the vac source or on the fuel return part? I think you may have connected it to the fuel return because there shouldnt be any fuel coming out of the vac part. The vac source allows the fpr to hold more pressure, allowing more fuel during WOT pulls because the spring resistance will be stronger because of the vac.
The vac line on the fpr should go to the intake manifold, if its not connected to anything, then it won't work.

08-22-2010, 02:55 PM
Whats the exact code you got?

08-22-2010, 07:23 PM
ok i understand that. see the pic you sent of the fuel system... my fpr is above my fuel filter and all of that is located at the back of my car. and on my intake manifold there is only 2 vac lines conected and there is 3 ports for vac. mine kinda looks like tho one in the pic.

08-22-2010, 09:32 PM
One of these 420a guys is going to have to chip in here. Usually theres a return and a vac line on the fpr regulator. Not sure on the 2g n/t models. Jason or Dave should have an answer for you.

08-23-2010, 10:02 AM
You have a later model fuel system. Only a few early production 96s has the earlier (and better) fuel system with the filter in the bay and a return line. So I'm not familiar with the newer systems much.

Is there a vacuum line connected to the FPR?

08-23-2010, 12:15 PM
I checked it and i dont see where a vacuum line could be! i see the hose that runs from the top of the gas tank to the fpr, then a metal line that runs somewhere else!

08-23-2010, 12:54 PM
Check on the fuel rail itself. On the passenger side, is there a metal piece (looks like the piece in that pic you posted) with a hose on it?

08-23-2010, 01:00 PM
Yea i did that also but on my fuel rail it just has 2 valve stems kinda like a tire valve. and the FPR is at the back of the car. I know about the FPR on the fuel rail because thats how it is on my 95 Eclipse.

08-24-2010, 10:20 AM
Ok if your fpr is at the rear of the car by the rear tire then there is NO VAC line going to the FPR. Your fuel system runs consistent pressure around 40-45psi. Put a fuel pressure gauge on the test port on the passenger side of the rail to check fuel pressure.

However I doubt your problem is related to the fuel pressure. The most common issue after rebuilds would be setting the timing wrong. Which would cause low vac and backfiring. I would do a simple compression test to see what numbers you get. If they are very low then the timing is set wrong.

08-24-2010, 10:38 PM
Ok but before i took the engine out of the parts car i have it ran fine... then all this started happening when i put it into my eclipse. ok after i check the compression would you re time it? and i thought the ECU controlled the timing? so i was told! thanx for the help!

08-24-2010, 10:51 PM
and I think i checked the pressure valve on the pass side and i didnt have any pressure

vanilla gorilla
08-25-2010, 07:53 AM
Cam timing is adjusted by hand via the timing belt. Ignition timing is ECU controlled.

08-25-2010, 11:05 AM
Oh ok! thanx man! i didnt know that! so i guess i need to check the timing and if its off just reset it!

08-25-2010, 11:15 AM
So you didn't remove the timing belt at all? Then the timing should be ok. When u switch the key on do you hear the fuel pump prime? Hook up your fuel pressure gauge and then crank the car up. Make sure that your gauge is depressing the valve in the fuel rail. Or you can remove it with a tire valve tool. The car won't start without fuel pressure so have to have some if it starts up

08-25-2010, 11:04 PM
Yea i didnt touch the timing at all. and to tell you the truth i took that tool and depressed the valve and pushed it in and nothing came out. not even a sound of pressure and the car still starts but dont run good at all! and i dont think i can hear the fuel pump prime. so since it dont have pressure how would i get pressure back there?

08-26-2010, 07:53 AM
Pull out the rear seats and under the metal cover on the left is the fuel pump. Take the 4 screws out of that and you will see the top of the gas tank. If the pump is working you will be able to hear it there and you can test for power, ground. If you have power but the pump is not on than maybe the pump went bad. You will only get power to the pump for 1 sec on the prime pulse and while the car is running.

08-26-2010, 11:30 AM
Ok so ima try that. and if its not pumping ima replace the fuel pump, but would that cause backfiring? and do you think that would solve my problem? Thanx for the help everybody! Yall are great ppl, im still young and wanting to learn about cars cause i love them so much.

08-26-2010, 12:35 PM
If your lucky the 2 problems are related. Fix the one you know about first and if the backfiring doesn't go away then move on to something else. Do you have a check engine light when the car is running?

08-26-2010, 11:03 PM
yea the codes are 1698, 1899, 1487. So would you try the fuel pump first or what? How do you get that pressure back to the fuel rail?

08-27-2010, 11:51 AM
What are the codes? It should have given you a brief discription of each.

08-29-2010, 05:27 PM
ok they are 1698- Fuel Temp to high, 1899- Fuel temp sensor B circuit mal, 1487- Fuel Delivery Error. I just checked the fuel pump and yea it does prime and then once i let it prime i went to see if i had pressure im my fuel rail and it blew out a lil bit of air just a lil. fo you think it could not be pumping right or the fuel filter is clogged?

08-29-2010, 07:45 PM
The fuel filter would be good to go ahead and change if it hasn't been done in a while. I wasn't aware that we had fuel temp sensors on these cars. You really need to get a fuel pressure gauge hooked to that rail to see whats really going on. Its really rare that a fuel pressure reg goes bad but the fuel pump might not be supplying enough fuel to built the pressure the system is looking for. Or maybe a really clogged filter could do this also.

What kind of fuel pressure tester are you using? If your having problems with that valve at the end of the rail you can remove it while your checking the pressure. Just use a tire valve removal tool.

One way I always diagnose a fuel problem is to use starter fluid to crank the car on. I spray starter fluid in the intake pipe and once the motor starts a bust of fluid every second or 2 will keep the motor running smooth. If the car runs good then you deff know its a problem with fuel delievery.
WARNING: this can be dangerous is not done carefully. An intake backfire could shot a fire ball out of the intake pipe so be careful if you decide to try this.

08-29-2010, 09:07 PM
ok i got another fuel pump too. so ima try to hook the gauge up (it a big round gauge with a rubber hose on the end.) and check the pressure... then ima change the fuel filter and chang the fuel pump. I have a extra pump so that works out. thanx for the help. anything else or great advice you have for me about these cars?

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