please help

[bpursey26]

Got a 90 B2 2.9 started having a issue after filling thought it was a fuel filter issue changed the filter ran good for 2 min and started doing the same old stuff so it idles fine but when u try to accelerate it stumples and RPMs bounce around. Also tried to swith out my throotle body my TPS and my idle air contol and it all made it stumble worse. So I guess the question is has anyone had a issue with a weak fuel pump and if so does it idle normal but choke out underload also rented the fuel preasure test gauge from auto zone but haven't ever used one and what's the PSI suppose to be at. Any hp or input would be greatly appreciated.

 

[06RangerXLT]

fuel pressure should be high. i believe in the 60 psi range. Sounds like a fuel pump alright. contact ADSM here to find out.

 

[Gary101386]

timing?

 

[jhammel85]

Fuel pressure for the 2.9 should be around 40 psi with the key on and engine off. Just with the pump(s) priming. With it running it should be around the 31-35psi range.

If its over, most likely the Fuel Pressure Regulator is bad. If its under, I would assume the pump.

I would check the engine for codes if the fuel turns out to be OK.

Here's the How to: http://fordfuelinjection.com/?p=13

EDIT:

Did you say that this happened after a fill up? Maybe it's bad gas? It's rare but it happens...Try dri gas.

 

[bpursey26]

Doesn't the timing get auto advanced and retarded just a thought but I will check it out and to through something else in the motor is out of an 88 and it was put in two weeks ago drove it for like 5 days went to fill it up for the first time drove it home fine and know 5 miles down the freeway this started and on the timing being off wouldn't it run like crap ideling also just cars getting on my last nerve and putting all my time and not getting any results yet thanks everyone

 

[bpursey26]

Ok posted up in list title fuel has all updayes help is still needed please delete this posting

 

[Duane867]

Fuel pressure for the 2.9 should be around 40 psi with the key on and engine off. Just with the pump(s) priming. With it running it should be around the 31-35psi range.

Excellent copy & paste job.

 

[Ozwynn]

What about catylitic converter?

 

[bpursey26]

When I did the swap the cats still looked good and would that make the motor just start running like crap out of no were

 

[bpursey26]

So when I started the B2 today sounds like its missing while ideling now so plan on pulling plug by plug to see if its a wire plug cap rotor anyone ever had a weak coil that could cause this or my buddy is telling me computer but wouldn't that make it hard to start and not run long if at all

 

[adsm08]

Things to check:

Check spark quality. Pull the coil wire off the distributor and stick a thick handled screw driver in the end. Without touching the body yourself hold it 1/4 to 1/2 inch from the hood prop rod and have someone crank the engine. You should get a strong blue snapping spark. If you get shocked, you need new wires. If you get a crappy weak orange or yellow spark just rebuild the ignition system. You are supposed to replace the coil TFI and pickup together.

Check the fuel pressure regulator. Just pull the line off and look for fuel in it.

A running fuel pressure test in your case is problematic because as the engine begins to idle erratically it will simulate high throttle position and allow the fuel pressure to come up. Check it, but you are only looking for the pressure to drop below 25 PSI, not a likely suspect IMO.

Check plugs for carbon, fuel, or oil fouling and for any that look steam cleaned.

Unplug the O2 sensor and try again. If it goes away, get a new sensor.

If this only happens shortly after refueling (as the original post suggests) remove the orange line from the bottom of the throttle body and plug the port somehow. Try again. You may have at some point flooded the carbon canister. That can also cause some unusual issues right after filling the tank.

Lastly, if all else fails, put a vacuum gauge on the intake and rev the engine by hand. If it starts generating pressure instead of holding vacuum you have a massive exhaust restriction. Or someone installed a turbo. Start disconnecting pieced of the exhaust one by one until it begins running properly.

 

[bpursey26]

Ok good info will be checking tonight and post either tonight or tomorrow thanks so much just want my B2 back

 

[adsm08]

I very much understand your frustration. The old systems can be hard to diag because they are so simple and don't give you a lot of information.

 

[bpursey26]

So I checked high preasure fuel reg and no gas comming out the back then did fuel test and key on its at 38 when running its at 32 also tries disconnecting line from throttle body to carbon cannister and cap it and no change. Pluhs are new and still look good so still have a couple things to check. I have a couple missing connectors that dont have a home im sure the go to A/C one wire is black and other is black/yellow and other connector is tan/yellow and other is Lt grn/purple. And any way the map sencor is bad heard alot about these.

 

[adsm08]

It's possible that the MAP is bad. But that should have it setting a code at some point. On the other hand, it will barely run if the MAP is good and you unplug it...