TeamCapri
Tech, Repairs, Upgrades => Capri N/A 89-94 => Topic started by: ilarson007 on December 24, 2007, 06:23:00 AM
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Anyone know what the fuel pressure should be? We are going through things step by step trying to figure out what's wrong, and need to know what it should be. I checked the fuel section of the service manual and didn't find it.
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Also, if we need to replace injectors, what is the best place to buy (i.e. cheapest)... If there are upgraded injectors that cost less than stock, please let me know!
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You can have them cleaned & flowtested by Witchunter performance...MUCH cheaper than buying a set.
http://www.witchhunter.com/ (http://www.witchhunter.com/)
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I would of thought somewhere between around
45-55psi... but correct me if im wrong...? not sure.
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it (the manual) said that at idle it's between 38 and 42ish, but that it goes higher during starting or during high fuel demand. If I have my injectors serviced, do they know what specs to look for, or do I need to provide them? Cause I have no idea on anything to do with injectors.
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yeah, not sure mate, from what I've heard though, anything under 30 is not a good sign, then you have a leak somwhere.
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here have a read of this...
http://autospeed.com/cms/A_107986/article.html (http://autospeed.com/cms/A_107986/article.html)
Regards,
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Fuel pressure should be ~30+ psi at idle and climb higher under heavy load or a hot start.
You can just tell Witchhunter you'd like to get your injectors tested & cleaned.
I highly doubt thats the problem though, at least one or two would be working, and you'd get sputtering trying to start. If NONE of the injectors are working its likely an electrical issue
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well, we are probably going to check the entire fuel line, with injectors last (seeing as they are the most expensive). I think for the fuel test we pull the line apart (held with that little metal clamp, like the vacuum lines) and test there (it's after the filter, before the fuel rail). We might try to start with replacing the filter, then the pump, then the injectors, but whatever happened to it in May, it happened while driving, so...
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Why not "troubleshoot" things instead of poking & hoping with replacing stuff?
pop the fuel line off the filter, pop on a new line running to a bucket. Jumper the green terminal near the passenger strut tower. Turn the key on in the car. You should hear the pump kick on, and fuel should flow from the filter.
You can pull the entire fuel rail off the manifold, and put it in a 5 gallon pail or something similar. CAREFULLY have someone crank the engine for you, you should see each injector fire. They fire in pairs (1&3 and 2&4 i think) Observe their spray patterns, and make sure none are leaking. Careful when doing this that you dont remove any of the injectors, or you'll damage the o-ring seal around it and it'll leak like crazy.
Replacing the filter is not a bad idea. But fuel pumps can get very expensive, as can injectors.
If you do have to replace the fuel pump, replace it with a 190lph Walbro performance pump. They're cheap, like $70 shipped on ebay. Dont bother with the 255lph, they're overkill, and they are really loud when they run. An OEM pump is going to cost you and arm and a leg from the dealer.
Are you getting spark?
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Yea I'm getting spark. That was one of the first things we tried. We bought new plugs, and set them out of the engine and all four sparked.
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What do you mean by "Jumper the green terminal near the passenger strut tower."
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Well, my guy checked it today and it was at 18psi! So as long as that is too low, we finally know what's wrong with it! I'm calling the dealership tomorrow to check.
EDIT: Rocketman, do you know the part number for the stock pump (we are getting rid of the car, no sense in upgrading the pump unless it is cheaper than OEM). As long as that is the problem (I think we will try the filter first, then the pump)
[ January 06, 2008, 09:14 PM: Message edited by: ilarson007 ]
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Hey iLarsen! Change the filter Then recheck the pressure but most likely not. Is the pump making a horrible noise? I've had two go bad and they really howled. The factory pump is likely expensive. There was an outfit in So-Cal onEbay selling aftermarket pumps for about 50-60bucks. I'll check myself and if not I'll try to find them and post you. Gus.
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No idea what the stock pump is but its likely expensive as hell.
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Hey i! I tried to research to no imediate avail. You might try a local discount supplier. I'll continue to research tomorrow. Gus.
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Well, the ones I see on eBay (for the most part) are the Autoteq 255lph, for like $70. *Runs and checks the internet... The Walbro is $100
EDIT: Is it advised to replace the strainer and gasket too?
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Well, I just talked to the guy at the dealership, and he said it should be at 38 at idle, so... I'm looking for a fuel pump now.
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put in a new fuel pump, still didn't fix it... I'm getting really f@#$*%g tired of this car.
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fuel pressure regulator ?
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I don't know if it is the pressure regulator, but we were thinking more of the relay, because the pump is not getting the full 12 volts when we crank it. Knowing that the pump does not have 12 volts, does that ring a bell for anyone else?? :confused: :confused: :confused: :confused: :confused: :confused: :confused: :confused:
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Well the voltage to everything in the car is going to be a little low when cranking...that starter sucks down a load of power.
To test you can run a piece of heavier guage wire to the pump, on a switch or just when you are ready to crank, that will jump the voltage up a bit. You could also hook a battery charger directly (isolate it from the rest of the car) when you are ready to try cranking. (keep in mind polarity)
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like 9 or 10 volts? thats 2-3 volts low. is that too much?
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Yes 9 - 10 volts when cranking is normal... As Rocketman said earlier, the starter motor causes the entire electrical system voltage to drop. If in doubt measure the voltage at the battery whilst cranking and compare it to the voltage measured at the fuel pump when cranking.
Have you changed the fuel filter yet? As you said it happened whilst driving, so that would be the first thing I'd replace, then clean or replace the filter gauze in the tank at the pump.
Then check the fuel flow as described in the manual. Volume pumped over time. Trying to measure fluid pressure can be highly inaccurate. Thats why the manual uses the volumetric method of checking.
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well, we didn't replace the filter on the firewall, but we did replace the whole fuel pump. I still think the power may have been low because the batteries we were using weren't fully charged (been sitting since May), and etc.