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  #1  
Old 09-20-2011, 06:29 PM
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Default idle surge, running rough, guzzling gas - 88 Ranger

Was searching the interwebs, landed on that thread, unfortuantly it's like a 2003 Ranger..

88 Ranger Auto, 2.9 EFI - Bought it this weekend. Know nothing about the truck, nothing about Ford, or this engine - My first Ford, first pickup. (Was a die hard K5 Blazer guy)

Ok, so the problems. Starts right up, engine sounds good, intermittently- but often the idle surges up and down a few hundred RPMS. Shudders until I mash it enough for 'WOT'. Most of the time it runs perfect cruising along the highway, though the low RPM of cruising ocassionally causes surging. Runs very smooth when I mash the pedal. Dies at almost every stop light/sign, usually lightly surges, surges more drastically until it just dies. Also, GUZZLES gas.

So I just bought it, new plugs, wires, cap and rotor looked brand new (bet the PO did that trying to fix it) plugs looked new'ish, but heavily covered in carbon. Replaced PCV valve and grommet, gunna do the filter later tonight, just to rule out easy new car/maintainence things.

Read a lot about the IAC valve and TPS being the culpret, took off the IAC and it looked dirty, but nothing blocking, spring rod thing moved pretty good.

TPS- resistance read 0.9'ish, I forget, but fully open it was in the high 3s and that's it. SEEMED to raise smoothly as I opened the throttle.. but I dunno, all this electrical stuff is new to me. Took me 10 minutes of cussing to figure out where the OBD1 plug to pull codes was. Oh and btw I THINK I have 12, or 121. So Idle speed, or TPS right? And 89, for the tranny. Apparently Autozone doesn't carry OBD1 scanners anymore.. what bs. The 89 flashed twice, quickly, and the 12 or 121 was slow, I'm just confused cause the last flash seemed seperate, but I'm not sure.

At some time the PO removed the intake manifold at least, since a lot of vacuum lines and wires are labled, I plugged in a vacuum line from the bottom of the air filter area to the air box that was undone when I bought it, and there was a ground cable (I assume) undone, with two wires on it so I bolted it to the manifold to a little bolt, seemed like it was were it was supposed to go by the 'memory' in the wire, but no idea. Guess this guy forgot to put back a few things.. just don't know why it was taken off.

Need help, this sucks, don't want this to turn me off to Ford, kinda diggin this little Ranger. This is why I always stick to 1986 and older, MANUAL trucks... oh and btw think I have some transmission problems, I swore never again will I own an automatic.. oh well.

Last edited by MrSchaeferPants; 09-20-2011 at 06:35 PM.
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  #2  
Old 09-20-2011, 07:41 PM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

It could be the Mass Airflow sensor, also look for any vacuum leak ahead of the MAF.

Tom W
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  #3  
Old 09-20-2011, 07:48 PM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

Quote:
Originally Posted by tpwsr1 View Post
It could be the Mass Airflow sensor, also look for any vacuum leak ahead of the MAF.

Tom W
Do I have a MAF or MAP? Cause there's nothing on the air cleaner/tb. Just the one on the firewall. How can I check that one?

Also, noticed my tv/kick down cable is jacked up. I can't find one (online) at orileys or autozone. So I guess that'd explain my hard shifts. Not sure if on the A4LD its a tv or a kickdown cable. But the way it's ran it melted against the exhaust, and it's too long (even adjusting it) to stay on the throttle pedal. Man, what I really need is someone with a similar ranger to park next to mine and just cross compare. Slowly finding things that are not quite right.
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  #4  
Old 09-21-2011, 06:47 AM
Psycho Pete
 
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

I think I have a kick down cable somewhere. I will have to look and see.

Only later California Emission 2.9Ls have a MAF system, federal emission, or the more common ones only utilize a MAP sensor. It puts out a frequency based on vacuum.

This might be a lot of help for you -

http://www.fordfuelinjection.com/

Luckily that's not an EGR model.

I might start with plugging off vacuums that aren't necessary for the engine to just run to see if there's a vacuum leak. There's a charcoal canister line that hooks up under the TB that's hard to see.

Dirty or mis-adjusted TPS can cause problems. Might be worth while to clean if it has a lot of carbon build up around the throttle plate, and look for the procedure to set the TPS base voltage. That way you know you are good there and will give you an opportunity to test the TPS sensor while you are doing it.

Could also be a dirty / sticking idle air control solenoid.

Big help will be pulling codes. Does the CEL turn on when the key is just on run (to make sure the bulb isn't burnt out)? Pretty easy to do and can usually get you some hints.

http://www.corral.net/tech/maintenance/eecivtest.html

Fuel filter; change it. PCV valve; change that, too. Change the trans filter and top if off with new fluid. Highly recommend an aftermarket transmission cooler. Fuel pressure test never hurt, always good to know the vital stuff is in good order.


Reread all of your post

Fords are a bit different; Chevy has stored memory codes and KOER test. Ford has a KOEO hard fault, stored memory, and the KOER.

The KOEO is first, codes are output twice, then you a single separator pulse; then you get stored memory codes output twice. They is done with the key on, engine off. 2 tests. Then you can move onto the KOER if the engine is warm - otherwise you will get a temperature out of range code. They will be 2 digit codes.

Best to check TPS with an analog meter so you can watch it sweep smoothly with the needle.

1985 and earlier 2.8L trucks are far more complicated than these... They have a half-breed carburetor and electronic fuel injection system that you would have specialize in to know how to repair.

Fore-thought; if the upper plenum looks like it has been removed, spray around with carb cleaner and listen for the idle to surge. That PO was asking for a vacuum leak if the plenum gasket was reused.
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1987 Ford Ranger Short Bed 5.0L/T-5 Project
1988 Ford Ranger Long Bed Parts Truck
1993 Ford Tempo 2.3L OHV HSC Auto - D/D Stock.
1999 Honda Accord VTEC Auto
2002 Dodge Caravan - 3.3L Auto

Last edited by Psychopete; 09-21-2011 at 08:14 AM.
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  #5  
Old 09-21-2011, 03:44 PM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

I'll start with a few of those things.

I've read a bit of that these last two days as I'm tinkering and learning about stuff. Another thing, my temp gauge doesn't work, so I'ma see if that's working, and I have a sneaking suspesion the thermostat is stuck because it never feels like there's coolant in the upper hose. And I believe I read if the sender isn't working that'll cause gas guzzling. I guess if it's reading cold, it tells the pcm to shoot more fuel, like a choke I guess? I have no idea, just guessing, either way I need that to work.

Still haven't done the filter yet, I have a question though, the filter looking thing before the pump, is a sediment tank? Something I should remove and clean or something? I needa snap pics I have tons of questions and no idea what these componets are.
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  #6  
Old 09-21-2011, 05:48 PM
Psycho Pete
 
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

it's a fuel reservoir, do not take it apart. It will not seal back up.

2 temp units though, the driver's side is the gauge sending unit. On the passenger side is the coolant temp sensor that the computer uses. But yes, that can have a bearing on things. They tend to make the truck hard to start when they fail after it's been setting for around an hour.
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1987 Ford Ranger Short Bed 5.0L/T-5 Project
1988 Ford Ranger Long Bed Parts Truck
1993 Ford Tempo 2.3L OHV HSC Auto - D/D Stock.
1999 Honda Accord VTEC Auto
2002 Dodge Caravan - 3.3L Auto
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  #7  
Old 09-21-2011, 08:35 PM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

Quote:
Originally Posted by Psychopete View Post
it's a fuel reservoir, do not take it apart. It will not seal back up.

2 temp units though, the driver's side is the gauge sending unit. On the passenger side is the coolant temp sensor that the computer uses. But yes, that can have a bearing on things. They tend to make the truck hard to start when they fail after it's been setting for around an hour.
Ok ya I verified the gauge works by grounding the sending unit. I thought that's what the other one was with the two wires, since I couldn't see how the gauge unit with only one wire would send info to the computer. I changed the thermostat out, I didn't believe it was working right, figured it may have been stuck open, but it wasn't I think the fluid was low, or possible air bubble in the system? Because now it works. Dunno why though, it had that little deal to let air through on the t-stat (old one, as well as my new one) oh well.

Cleaned the IAC valve, cleaned the throttle body. After fiddling around with it yesterday, it didn't shut off to or from work, dunno what many things I played with did it but oh well, now it idles high, but that's my fault for F'ing with the idle screw... used that to get my tps resistance right before I read more on it, oh well, tonight I'll read on how to reset the screw, and adjust the tps the right way.

Sprayed everything with carb cleaner, no vacuum leaks I can find.

Oh ya and btw, saw a bulge in my passenger carpet, wondered what that as, the fuel cut off thing, it was unscrewed, upside down on the floor. So I bolted that back up, if it works, perhaps it was bumping around, that button ontop hitting against the carpet while driving? I dunno. There's a lot of things I'm finding.

Last edited by MrSchaeferPants; 09-21-2011 at 08:44 PM.
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  #8  
Old 10-01-2011, 10:30 AM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

Finally had some time to play with it. Changed out the filter. The idle problem since cleaning the IAC is scarce, still does it ocassionally and shuts off, but rarely now. I don't believe it was guzzling gas, I think it's the fuel float, sending unit thing. Fixed my speedo, so now I'm able to use the trip odometer to find out my mpg. I thought I was going through gas like crazy, but when I fixed the speedo, I topped off the tank, and it only took 2 gallons (gauge said 1/4 tank). So I'll figure that one out.


Next thing I need to address is my damaged detent cablef or the tranny, and look into a new input seal. It's loosing fluid, only if I drive it for a while, short trips it doesn't leak, right at the bellhousing, think I read leaking there is not uncommon.

Also adjusted idle speed and tps a little. Adjusted idle to 850 with the screw, then put the tps to as close to .96 as possible.

Ran a whole can of seafoam in the tank, so I'ma burn as much of that as possible till I fill up and count mpg, but I'm sure the seafoam will alter my readings, so I'll count about 3 tanks to get a more accurate idea. When I bought it I also put half a can in the motor, it's very sludgey, or was, when I replaced the pcv there was goop in the valve cover, so after running the seafoam for a few days I got it good and hot and did an oil change, hopefully it got a lot of that out. Truck was sitting for a while before I bought it.

So hopefully some junk yard will have the detent cable. No one sells it, even had a transmission shop make some calls to find one through Ford OEM parts places.
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  #9  
Old 10-01-2011, 07:04 PM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

I was right, it's guzzing gas, 10.5mpg. Even factoring in the seafoam I shouldn't be at half my mpg.

Found another ground d/c, dunno what it's for goes into a harness. It's the ground that bolts to the engine at the same place the upper part of the transmission dipstick mounts to. No idea what size/pitch the bolt is.

Went to a junk yard today and snagged a kickdown cable but it wasn't the right one. Took mine off, it still moves right, but where it attaches to the pedal is too much play, doesn't look like it'll engage unless that pedal is on the floor. Perhaps the PO obtained one that wasn't right. It's back to dying again, usually when I go from a good speed to a stop light, or slowing down a lot to make a hard turn.

All the rangers/bronco IIs I saw at the Junkyard had a vacuum hose from the airbox to the mannifold in a different spot, so I moved it, and then I noticed how the other hose comming out of the airbox goes to some valve that I assume opens closes the hot air ducting from the passenger exhaust mannifold, no idea if that valve/diaphram works, but the hoses are barely connected.

Still pissing out a bunch of tranny fluid from the torque converter area, and how far does that bracket on the tranny kickdown cable supposed to move (transmission side) I can move mine like 1/2"
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Old 10-10-2011, 07:41 AM
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Default Re: idle surge, running rough, guzzling gas - 88 Ranger

Well somewhat of an update:

Up to 11.5mpg from 10.5. I'll find out this next fill up if it's better, topped off last time 6 gallons, so this tank I'll be running lower to fill up with all new gas and have most of the seafoam gone. I think it'll kick up after that.

Idling problem is gone. I did various things all at the same time so I'm not sure what fixed it. Cleaned IAC which I believe helped, but did not totally fix. There was a ground cable on the back of the passenger head that wasn't connected that I put back on, not sure what it goes to, but I haven't once idled erratically nor has the vehicle stalled since.

But at the same time I gutted my catallitic converter, I do believe it was stock, and plugged. (little more pep in WOT, but it will be replaced sometime later. $219 for OEM.. not liking that, wonder what the laws say about an aftermarket one) Also replaced my O2 sensor. Which was new'ish, however I don't believe it was tightened down enough, because it took no effort with the wrench to unscrew it.

Also did the fuel filter. So between all of those, the engine runs very well now, next two fill ups I'll report mpg.

As far as the tranny, I believe I'll run it till it blows while I look for a 5spd doner vehicle, only thing that sucks is it does leak quite a bit, so if I want to avoid spending a lot of $$ on tranny fluid, short trips, because it only seems to start pouring out after extended driving.

Also considered finding a a4ld to rebuild myself, but only if I get it for cheap as hell or free. Don't mind spending $200 on a rebuild kit and attempting to rebuild for the learning experiance, only thing that turns me off is what I've read about the bellhousing possibly being misaligned or something and needing machining. Would much rather have a 5spd though
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Last edited by MrSchaeferPants; 10-10-2011 at 07:57 AM.
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