95 Aspire low power

[larry220]

Hi

Anyone got any ideas on this? My daily driver 95 aspire just started cutting out and losing power on the way to work last week. It only does this under load. If your sitting still in idle you can rev the engine and it runs just fine thru all rpms. It also starts right up like normal. But when you try to drive it it cuts out and bogs down when accelerating an gets very low on power. The check engine lite did come on and i get a code 18 by watching the check engine lite flash.

I dont know whats wrong??? I replaced the dist cap and rotor, plug wires,plugs are newer,air filter new and fuel filter. No help. I tried checking fuel pressure but on a 95 cant find the schrader valve.There is fuel coming thru the fuel filter but maybe its not enough pressure?? Any ideas out there.????

Thanks

[phantorn]

I does sound like you are losing fuel pressure

[larry220]

Ayone know where the schrader valve is on a 95 aspire to measure fuel pressure??? I got a hanes manual but it shows the valve on a 97. Its not there on a 95.?? Or where do you measure fuel pressure on a 95 Aspire?

Thanks

[phantorn]

I checked the service manual and it does not list a schrader valve.We only have the online maual though.Depending on your fuel pressure gauge you might be able use a tee fiting by the fuel filter.Maybe someone has a hard copy of the manual.Also it did not list any flash codes,can you get the code with a code reader?

[cyrus]

Hey larry, I saw your post on fordaspire.com too. Hopefully someone here can answer your questions since none of us could figure it out lol good luck.

[larry220]

Hey Thanks guys for all the replies. Do you think I could check the fuel pressure right before the fuel filter (or basically straight out of the tank). I would have to get some kind adapter as my guage only has the schrader type screw end. And the pressure amount would be different than measuring it a the rail. Also I may be wrong on the year. it may be a 94 and my tech manual is for a 95. Perhaps thats why my 95 manual shows the schrader valve but its not there on the 94. At least not where they show it is. I looked all over and could find one. I will try to get a code reader and get back to you.

[phantorn]

They make an adapter with a shrader valve that goes inline on the fuel rail might only be available on a tool truck though.Fuel pressure should be the same no mater where you check it as long as its before the fuel pressure regulator.

FUEL PRESSURE SPECIFICATIONS
Fuel Pressure at Idle 265-320 kPa
38-46 psi

Add a location to your profile maybe someone lives near you

[larry220]

I talked to a mechanic friemd of mine and he says it sure sounds like a fuel pump, He loaned me apressure guage with T fittings and so I will try checking the pressure around the filter. I did look up code 18 online and it said :Ignition Diagnostic monitor circuit failure.? So we will try checking fuel first and go from there. Cant find any vacuum leaks. Maybe I will have to get a guage for that too. Thanks so far.

[larry220]

Hello
Checked fuel pressure last using a T on output of filter. It was 38 at idle and increased to around 44 during accelerating(even when it was bogging). I let engine run for afew minutes and idle pressure dropped a little to 35-36 but still increased with acceleration. I didnt have time to do the fuel pressure regulator tests. I will do that tonite. Also I did replace PCV but no help. Do you think its enough pressure?? The bogging gets worse as engine warms up which does match the lower fuel pressure at idle as it warms up.???

[larry220]

Hey I think its the fuel pressure regulator. If I pinch the fuel return line out of the pressure regulator the car accelerates normally no bogging. There seems to be good vacuum to the regulator so it about has to be the regulator i would guess.

[FB71]

actually, you pressures look good. I would suspect a clogged fuel filter or clogged injectors.

[larry220]

Yeah you may be right. I suppose it could be dirty injectors or maybe even MAF causing short injector pulses(not giving it enough fuel). Oh well i got the pressure regulator ordered now and will put that on first and go from there. At least now I know I am getting close on this problem. Fuel filter already replaced.

[jglutz]

Anyone, I don't know, but what latches the fuel pump circuit on? If the problem is "cut out" and the ignition expendables where changed...sounds electrical to me?

[FB71]

PCM turns on the FP relay, based on tach signal from IDM circuit.

[larry220]

Im going to measure the voltages on the MAF and TPS sensors today. Although that doesnt explain to me why it accelerates ok at slow acceleration(No load) but cuts out under fast acceleration(or loaded).I would think if the MAF or TPS sensors were bad it would never accelerate or be very intermitent or wouldnt idle correctly. It starts right up and idles fine. So to me that rules out vacuum or TPS issues. Maybe the MAF isnt changing voltage as air intake increases or dirty injectors causing fuel starvation under load???.Like I said if you squeze the fuel return line at the regulator, fuel pressure increases alot(to like 70 psi) and then it seems like it accelerates normally. So_ dirty injectors, injector pulses too narrow, Fuel pressure regulator or MAF. Does it sound like I am on the right track now.?? I do have a new FP regulator ordered but it wont be here till tuesday. In the mean time I am going to check the MAF voltages and TPS voltages. If this was an distributor problem why would squezzing the return line make it run OK.?? Thanks for all the advice so far.