95 5.8 liter MAF problems?

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On Wed, 25 Jul 2007 09:53:04 -0700, john
Snipped


John Many people leave the engine running when they wash it. The 5.0 & 5.8 engines used a two piece intake manifold. Many of them experienced failure of the gasket between the upper and lower sections of the intake. If the engine was running when he wet it, it probably sucked some water thru the bad place in the gasket making it seal a bit better momentarily changing the the way the engine was idling. Replacing the gasket usually fixes that problem. I thought we had mentioned that as part of the check for vacuum leaks earlier in your problem - maybe it was another thread. You can check this gasket for bad leaks with a can of carburetor cleaner or even WD40. Don't use starting fluid (ether) for this. If that is the problem, it is a cheap straight forward repair to remove the upper intake, clean the gasket surface and replace the gasket using a very thin coat of sensor safe silicone sealer like the Permatex Black or Gray. You should be able to do this job in under an hour even with OJT. Allow it to set up for about 10 minutes before installing the upper intake. Also, if you do this, make sure you do not pinch the small plastic vacuum tubes that pass by the back of the manifold. That is very easy to do. IIRC, the 5.8L also has a torx head bolt in the middle like the 5.0L. I don't recall the size but, you will need to use a long 1/4" drive extension to reach it from the top. It is much less frustrating if you use electrical tape and firmly attach the bit and socket to the extension unless you have very small hands to fish it from under the manifold. If you get an upper intake gasket kit, it will have a throttle body gasket so you can disconnect it and push it forward out of the way. You don't have t worry about losing any coolant from the intake as it is dry. You must use a good accurate torque wrench to install the bolts or you will cause a bigger problem than you are fixing. You may be able to borrow one that will work accurately in the 250"/lb range. I do not recall the exact setting for those bolts. You will need metric tools and a way to adapt your sockets for the torque wrench to 1/4" drive unless you come up with a good 1/4" drive torque wrench.
I hope I have written this such that it is understandable. It has been a long time since I was intimate with this exact engine. I believe Tom who has responded above is still an everyday Ford tech with about a hundred years experience. His answers are usually dead on on the Fords given enough info.
Good luck
Lugnut
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Thanks Lugnut. You did mention the manifold gasket, but I didn't use your test because I'm leary of spraying carb cleaner at a running motor. Since the problem only occurs for about 65 seconds, I'd have to crank the motor, run around to the motor and start spraying at the joint between the lower manifold and the long curved stacks that follow the throttle body. Is that right, and what am I looking for? rpm change? It looks like I'd only be able to get to the left side. Why wouldn't spraying carb cleaner on a hot motor start a fire? Anyway, the ford tech (the one that wants $315 minmum to hook up the breaker box) said he didn't think it was a gasket problem. And the other guy (at the foreign car shop) told me it probably isn't the EEC. Seems like that leaves sensors. But, what do I know? Not that much.
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On Wed, 25 Jul 2007 14:37:29 -0700, john

I believe you are looking at the right one. You do not have to use the cleaner or whatever while the engine is acting up as long as it has stabilized. When the idle goes down, it simply means the ECM has compensated for it's inputs. If the gasket is bad, the idle will change when the spray hits the leaking area whether it is idle quality or speed. You will recognized the change it it is significant. You are very correct to be concerned about spraying flamables on a running engine. The pros do it routinely but, they also use WD40 quite often which is much less combustible and safer. Unless you have electrical sparks, the engine will not be hot enough to ignite carb cleaner or wd40. Ether is a different story.
The Ford tech may be correct about the gasket but, a problem like yours may at some point require the tech to make this test as part of the overall diagnosis. A good diagnosis is going to start with a thorough visual inspection to make sure everything is present and correctly connected. The next step will be a check for fault codes and the KOER diagnostics which will hopefully tell the tech at least which system he needs to investigate more closely. At this point, the tech should begin to do certain procedures that will pinpoint the problem. A good tech who can find your problem will be much less expensive in the long run than just throwing parts at something or spending a lot of time on something you do not and will not understand without first having a good fundemental knowledge of the system.
You are correct in being cautious but, you apparently already have a great deal of time and grief related to this problem. It may be time to place your faith in someone local who can personally examine the vehicle. Contrary to what you may feel after reading some of the stories about service organizations, most of them are people just like yourself who do not wake up in the morning looking for their next scam victim. They just want to make a living and most techs would much rather have a repeat customer than a one timer. If you go to a well qualified shop or dealer, they will be glad to show you their training and qualifications before beginning work. If they are certified ASE or Ford techs in emissions and driveability, they will have the proof.
Good luck
Lugnut
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No, no. I do not think they are all scammers. I think the Ford tech and the foreign tech were straight shooters. They just could not find the problem. The next step is apparrently very very expensive. I can't see spending $1000 bucks on this. I already have an offer on the truck. I just might sell it at this point. Damn shame, after all the maintaince and care I've put into it, but it is what it is.
I'm going to squirt some WD40 at the seam (fire extinguisher at the ready). And I may change out the TPS too.
Thank you, John
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When I washed the engine off to degrease it the water sealed around the gasket. Once it started to dry the speed went back up. So I replaced the gasket and they engine ran perfectly. No more high idle. ricker
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