I have been lurking for a few months now and I have decided to make my first post today.....primarily to inform all about the truck and to offer a couple of questions.<O</O

I bought the truck back in August and shortly after realized it wasn't as good a deal as originally thought. The truck was missing badly, and it had a vicious vibration when the AOD dropped into OD. I wasn't able to pinpoint the cause of the vibration right away, and to be honest, I immediately thought the trans was pooched.<O</O

After changing the obvious-wires, cap, button and plugs-the symptoms remained. I bought a fuel filter, and that is when the fun began. When I took the filter off the frame rail, the first thing I noticed was the weight....it weighed about a pound! I cut it open and I have never before seen the like of what was inside. It was half full of a brownish red deposit, that was non-metallic. I first thought rust from the tank but then thought more like fuel residue from a truck that sat around for long periods.<O</O

I changed the tank and filter and the problems persisted. My buddy owns a MotorVac, and he flushed the rail twice with marginal results. The last time I had the rail flushed, we noticed one injector was not firing (#2 right hand bank), but the plug was receiving a voltage signal. The injector was shot. Last week I finally was able to source a couple used injectors (after pulling plug 2 and 3 from the right hand bank it was obvious they were fuel starved) and I changed those two. In the process, the EGR tube disintegrated, so that was another $140 cost incurred. $140 for an EGR tube you might ask? I live in Canada where this item is a dealer only part. <O</O

I am happy to say, that cured the vibration and power loss issues.<O</O

As with all F150’s of this vintage, the dash gauges are wonky. The oil pressure gauge fluctuated all the time, causing the engine light to be on more than it was off. I never bothered to troubleshoot it. Rather, I installed a manual oil pressure gauge on Friday night (in the OD on/off button location on E40D dashes) and I was appalled at the oil pressure! 50 psi on cold start and drops to 20-22 psi when warm and cruising. The engine has 286XXX kms. I was happy about that.<O</O

<O</O

Now, for questions.<O</O

Since changing the injectors, the truck pings rather badly under load. I set the timing at 10 with the spout removed, but it still pings. Initially it was at 15, with considerable more ‘seat of the pants dyno’ power I doubt it the pistons are carboned up with the 2 flushes the engine had. Any suggestions?
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And, when firing the truck up, the idle surges. If I let it sit for a couple of minutes before driving off and slip it in gear, she will stall….I suspect IAV. Is there an easy way to check? I suspect these 2 issues are related.<O></O>

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Sorry for the long diatribe, and I promise any post I make in the future will not be this long!!<O</O

<O</O

Dan

 

Welcome to FTE

IAC can be pulled off and cleaned. At least my 92 can. Take it off(2 bolts) and then take it apart(2 screws) and flood it big time with TB cleaner. That cured my low idle/stall situation. All the posts about cleaning it say LOTS of TB cleaner.

Sounds like you need the timing back towards the 15. I'd give that a try and see if it helped any. Are the rest of the injectors clean?

Do you have any codes?
http://www.fordfuelinjection.com/?p=13
Here's how to check them if you don't have an OBD1 scanner.

I'd say you're close to having a good running truck now.

Good Luck
Bob

 

Thanks for the info Bob.

I never had any TB cleaner on hand yesterday, so I never bothered cleaning the IAC. I'll pick some up on the way home tonite and give that a shot.

I forgot to mention in my original post that when the timing was set at 15, it pinged as well. I suspect the distributor may be off a tooth. I'll see what I can do about that later this week.

After buying the truck, I ran the codes, which there were lots. I can't remember which ones. Since then, I have replaced the distributor and EEC from a '92. Perhaps running the codes would be the best place to start now. Interestingly, the EEC never identified a problem with the injector that was not firing. Maybe the logic in the computer isn't 'smart' enough to recognize that.

I'll keep posting with my results.

Dan

 

When you find an engine with the timing at 15 to me it means the timing chain is shot.
Check for excessive play when you rock the engine back and forth while watching the rotor.

 

That is what I thought initially, but I remembered I had swapped distributors shortly after I bought the truck. Wouldn't be the first time I installed a distributor 1 tooth out! When I check it, I'll check the chain for excessive play.

Dan

 

To update, I cleaned the IAC last nite by removing the unit from the TB and removing the solinoid. The valve body was not really that gummed up to the naked eye, but after washing it out with TB cleaner, it was apparent there was a substantial amount of crap in the lower valve body. I let the cleaner soak about 5 minutes each time I blew it in, and I did that 5 times or so. Because I used the rest of the can to clean the TB itself, I really couldn't tell whether the symptoms of erratic idle was cured or not last night. I started the truck before leaving for work this morning and it didn't seem any different (the truck is not my daily). I'm starting to suspect the TPS, or a combination of the TPS and IAC.

One thing I didn't realize until last night, when starting the engine cold (less than 40F), there is no fast idle. The truck occasionally revs to 1500rpm on start up and settles in at 650-700. This morning when I started it, it fired right up and struggled momentarily at 700rpm. I gave it a couple of kicks, it settled at 900 or so, then down to 650-700, where it seems to struggle to maintain idle speed. After letting it idle for a couple minutes, I slipped it into reverse and the rpms dipped to 450 and once the IAC caught it, up to 550-600. Into drive, and it acts in a similar fashion. Occasionall when I have done this in the past, it will stall. If I am reading the symptoms correctly, I believe the solinoid on the IAC is weak or maybe the engine coolant sensor is faulty. The truck does run rich.

No update on the pinging. I will double/triple check the plug wire routing and maybe even rotate #1 cyl to TDC to confirm the distributor is in the hole right.

Dan

 

Welcome to FTE

AOD: Install the largest external transmission cooler you can find, and stay OUT of overdrive in heavy stop-and-go traffic.

The constant upshifting into O/D and downshifting into D fries the transmission.

 

The truck has an after-market trans cooler. Should be good there. I do not tow, but occasionally haul heavy loads.

I never drive the truck in stop and go traffic....I live in the country. Usually, the only traffic problems are caused by funeral processions!

Actually, the old AOD is working quite well. Good solid shifts all the time. The vibrations I mentioned at the beginning were caused by the engine only firing on 6 of 8 cylinders, and became really noticable when the revs dropped to 1300-1500 in OD (40-50 mph).

Dan

 

Being a tooth out won't hurt anything if the timing light is still showing 10* BTDC with SPOUT jumper out. Your distributor housing may be clocked a little wierd, but the 10* will still be the same. I've actually had to stab my VW dizzy 3 teeth out from normal because of interference problems with the linkage on my twin carbs so the condenser (yes, still breaker points ignition) wouldn't hit the linkage before I got it to the required 6* ATC. Remember, you're rotating the housing to make #1 fire at the right time. Timing is simply a matter of the relative position of the housing to the position of the rotor when it's time for #1 to fire. The engine won't care where the dizzy housing is pointed. I've thought about rotating the one on my 'Bird to get the connector for the TFI away from the WP bypass hose. Problem with that is the OP drive shaft may or may not come out with that dizzy. If it comes outta the OP but not outta the TC, I'm hosed and gonna have to pull the TC to fetch the shaft. (3.8L V6 in the 'Bird has the OP built into the TC).

The pinging may be from lean mis-fire. Have you checked for vacuum leaks yet? Is the pinging worse at light throttle (higher vacuum) or WOT? Check the EGR to make sure it's closing good. Block it off to verify it isn't causing the ping, but you'll want it back for fuel economy on highway mileage.

Pull the EVAP canister vacuum line between the throats of the throttle body, and connect a vacuum gauge in it's place. If you don't see 18 inches of vacuum or better, chances are you've got a nasty leak to find. Check out my gallery to see where my leak was. It looks horrible, but the job really isn't that bad. I spent more time taking pictures and cleaning stuff up than I did pulling wrenches.

As for timing, I'm running my '92 where Ford says to run it. I'm sure I could possibly get another MPG or two out of it if I bumped it up a couple degrees. But, I've got 155K on her now, and I'm not pushing my luck.

 

Ditto on checking for vacuum leaks. That would explain the pinging and idle problems. There are several possible places where you could have a vacuum leak, and some of them aren't very near the engine. Check each and every line, replace any that look questionable.

You should also check to make sure your throttle is correctly set. You'll need a meter to check that the throttle position sensor is in the correct position. If the engine was running poorly before, it's possible that someone tried to adjust idle by turning in the throttle stop screw. Turning in the screw too much makes it impossible for the IAC to regulate the idle speed properly.

 

To update this thread:

1. The distributor is fine. I double checked the button postion on #1 cyl at TDC...and it's bang on...so to speak.
2. The pinging, I believe, is being caused because the KS is not plugged in!! I'll have to wait to get underneath the truck to look from there. I have a couple buddies who have pits.
3. I reset base idle (timing set at *10) according to the Ford Manual.
4. I have cleaned the IAC Vv 3 times, I have power to it and it still has no fast idle at cold start.
5. I verified ref voltage at the ACT sensor....for some reason I am doubting this sensor. Since it has gotten cold, fast idle has disappeared....and I cannot think of another sensor that would cause this.
6. I ran a scan on her this morning and had 12, 25, 33 and 44 (I explained in an earlier post).
7. As for vacuum leaks, I have made a couple feeble attempts with no smoking guns. I can draw 20 inches of vaccuum with a hand pump and it holds pretty well. I realize that is not as reliable as acetelene or propane, but as I said, I haven't been able to really delve into chasing vacuum leaks.

That is where I am at now. The truck starts, idles fine once warm, pulls hard and does everything I need it to do. I could certainly do without 5 MPG, but I'm not really complaining about an 18yo truck with 200+ k miles on her! I know better than that.....

Dan