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1991 Ford Aerostar Question: hard cold start, rough idle, no power

 

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nighthawke, 3.0L V6, South Bend, IN, January 07, 2009, 08:44
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I've run the devil out of my Aerostars over the years -- and I now still have my third one a 91 with a 3.0 which I have used as a commercial vehicle in the past with good success (including the clacking wrist pin for the last 7 years!).

This one wasn't real good on fuel economy (probably due to the aforementioned wrist pin issue) but always ran reliably -- until I parked it about a year ago. My intention was to scrap it out -- but since I was hit by an uninsured driver in my main truck back in December and haven't gotten any settlement yet from my own insurance company, and since my number two truck's tranny died last night, I've been trying to revive the Aerostar -- well -- been trying for a couple of weeks since the accident.

It was last run about 6 months ago -- but the gas in it was old then. Only had about a gallon in it anyway -- so I filled it up with 92 octane and doped it with some gas dryer -- which should have resolved any fuel quality issues.

On starting it was very hard to start cold. I'd have to repeatedly start it, die, start it, die, etc... until it finally got warmer than dead cold and would idle (like a loping stock car) and it would rev up and down.

When I accellerated it would feather up and down and then stall out again when I released the accelerator.

It would stumble if I tried to put it in gear. Until I finally was able to get it moving down the road -- but, had no power.

Things I have done so far, and in order...

Cleaned the contacts on the TPS, and the sensor above the throttle -- not a MAS -- but some kind of air/mix valve I beleive ( I might know if my book hadn't gone to recycling) -- used injector safe throttle cleaner on the butterfly valve, cleaned the contacts on the distributor pickup sensor and the coil ground, re-seated and put di-electric grease on the coil wires and plug wires, replaced the plugs, changed the oil, checked for vacuum leaks -- plugged one that was open ( which was a leftover from some idiot who tried to run the lines from the evaporator core into the intake manifold vaccuum system -- that would have been a different idiot than me -- and I cleaned the pcv valve, but, when I tried to pull it out the whole top hose (the little one) came with it including a white plastic barbed fitting that broke off from wherever it goes.

Putting in new plugs resolved the cold start issue but I'm still getting a choppy idle and feathering and sputtering when I try to throttle (and when I do get it to throttle up it revs up and down like a clogged fuel filter --and I can hear the fuel pump running just fine when I turn the key)-- the remaining problems could be from the gaping hole I left when I broke off that barb...?

so, two questions -- where does the other end of that top line go to? I've hunted for two hours with mirrors and a stethescope and can't seem to find it -- the line is currently plugged off at the end I'm hoping to reconnect.

and -- if that's not the problem -- what next?

Thanks..

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  • Answer #1

    Andy Y January 07, 2009, 10:57
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     Master

    Does the van still have the emissions sticker? That should have a vacuum diagram showing the layout. If I understand, the fitting for the PCV broke? That would be a vacuum leak off the manifold. Is the hose loose/dangling? Cover the end with your finger and see if the idle condition changes.

    Autozone's website has free repair guides and they have a way to test the operation of the Idle Air Control (IAC) Valve, TPS, etc. You'll need a voltmeter/multimeter to test voltage but you'll be able diagnose the issue if fixing the vacuum leaks doesn't help.

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    nighthawke, January 07, 2009, 11:29
     Rookie

    Thanks Andy -- I don't know about the sticker -- but yes -- the hose is dangling from the pcv -- I have it plugged with a pneumatic line plug presently -- it made no difference -- but what I'm worried about is where it's supposed to be connected -- there should be a big hiss coming from it but I can't find it with a stethescope.

    The autozone info rates a 5 star buddy! thumbs up -- I'll check it and see -- this really seems like a vacuum problem to me.

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    Andy Y, January 07, 2009, 13:24
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    Happy to help! I was just thinking if that PCV has 2 hoses going to it, and 1 is broken, the other line going to the pcv will be open. After re-reading your first question I see you mention that. A new pcv valve is less than 5 bucks so maybe it's just as easy to get a new one. The diagrams on the autozone site show one line going to manifold vacuum (line closest to valve cover) and another going to something labeled CPRV (canister purge valve?). Maybe pinching off the line still going to the pcv will produce an effect on the idle

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    nighthawke, January 08, 2009, 01:04
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    Well, I bought a Hayes manual -- and in normal fashion it shows me a generic PCV circuit... useless, but the AZ diagram shown here

    http://www.autozone.com/addVehicleId,2148001/initialActio...

    shows the "CPRV" (which is what is shown on the van plaqard as well) as the "purge soleniod" which I was able to find by removing the upper radiator hose -- and -- yep -- that's where the barbed fitting broke away from. Tried in vain to make an ad hoc splice to go on it -- so I guess I'll try to buy one tomorrow, but, when I put a temporary plug in the purge solenoid, with the aforementioned plug in the line from the PCV, I had enough torque to sling snow.... only to be disappointed when the symptoms returned moments later -- which is what still baffles me about this -- I realized today that I didn't re-seat the condensor ground to the chassis -- so that's a possiblity -- but I'm kind of leaning in the direction right now, based on how the thing seems to be 'normal' one minute and a sputtering beater the next, that this has been a combo-vaccuum/electrical/ground problem --and you're right -- I would have put a new PCV in last night, but they weren't selling them at 3AM for some reason :(... but, I'm getting too old to work out in the snow all night ....

    When it starts to sputter I find that if I pump the throttle rapidly I can build up some accelleration -- and it's almost like an old carbeurated Datsun I used to have that needed to be re-seated with a new gasket -- but with that one, once it warmed up it was fine.

    So, anyway Andy -- thanks for the help on question one -- I think we have that one solved -- but, doesn't seem to be the whole solution -- still 5 stars.

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    Andy Y, January 08, 2009, 11:17
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    Right on, sounds like you're on the right track. I bet once you seal up the vacuum leaks and have them routed correctly, it'll be easier to figure out what else is going on - that's if there is anything else. I'm not sure why someone would install extra lines to the evaporator core. Let me know how it goes!

    Working in the snow?? ouch man I hope you fix it up so you can stay warm

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