So i have a 94 e250 with the 351w.

I have replaced

sparkplugs
wires
cap
rotor
coil
pcv
fuel filter
cleaned idle air control
cleaned egr
new air filter


I am getting codes 33 , 13 , 12

I checked compression
8-130
7-125
6-122
5-115
4-130
3-120
2-120
1-120

not bad for 255k on the od.

So my problem is she starts up fine. After idling very high for a about a minute or 2 she either starts to settle down then stutters and almost dies. or just starts the stutter before melowing down.

Also when giving it throttle it breaks up/loses power stutters.

I when i bought her 3 weeks ago she had the same problem although its defently not as bad or violent of a shake.

also the a/c used to almost kill the engine. after all this it now doesnt seem to affect it althought the a/c still blows threw vents then to defrost and so on.

i am almost sure it has a vacuum leak. among other things...leaking oil pan.

so with the code 33 it has a problem with the egr. which led me to clean the egr. didnt seem to help much. and did not clear codes.


Obviously imma try and get the codes fixed first. But i do hear such a loud vacuum leak coming from fron passengerside when driving down the road.

 

just went for a test drive. when giving it throttle and when letting go i can just hear air leaking out some where. such a loud vacuum leak...but besides this broken hose i can find where its coming from.

It sounds like front passengerside.



this hose is cracked but the symptoms where before I cracked it. i now have it tape together.<br/>

 

A 1994 is a OBD-1 System and code 33 is for TPS noisy or harsh in the computer, 12 is Idle Control Fault, 13 is DC motor not moving, So from here I'd say the IAC motor is on it's way out.........codes are really messed up depending on were they come from for OBD-1

 

Here's a Link to the codes for OBD I.

Cleaning the IAC is not effective, replacement is the key in solving the problem.

You write that when you start, is this a cold start?? It idles high, but comes down after a time. This could be a vacuum leak, besides the one plastic line that is broken, the old rubber lines could be cracked and dry rotted, best to just replace all the old rubber lines with new. Any plastic lines can be repaired with slipping 5/32" vacuum hose over the brake, or with heat-shrink tubing.

You write that you hear a vacuum leak on the right bank?
This could be the lower intake manifold leaking.

The compression check you posted, to me, seams very low.
With that mileage, you should be around 150 psi +/-.
I'm thinking........that the book said that compression should be no more than 30% from high to low number. So you fall in that range.

I parked my '94 2 years ago, with 326K on the clock, and the compression was still in the 140-155 range, and she was tired out. I played around with my '92 last summer, chasing all kinds of problems, the lower intake gasket was replace before me, and was leaking really bad, super high idle, pulled it apart, and went that far, pulled the heads........found that #7 exhaust valve had collapsed into the seat a quarter inch......September, put a '94+ re-man engine in, with roller-cam, and it runs like a brand new van today

 

A leakdown test will tell you more than a compression check. I'd start with the low hole.

 

Sorry but i dont have the tools to do a leak down test. as for the numbers, well it was a autozone rental...so i was happy with the differences in %.

So i have found


which is the egr tube. i have replaced it. but still had really bad idle and throttle problems.

So i then unplugged the TPS and it seem'd WORLDS BETTER. although that vacuum/noise is still there but ONLY when im drving around.

so i replaced the TPS and the idle is defently better....although not great seems high, but does not stutter or stubble ever 20 secs or so anymore.

but i still have a very weird throttle response while driving. i can hear something almost like purging air but like a constant that rises as i press the throttle then goes away once i let ago kind of like a ballon or bellow.

i have check for manifold leaks.

So i have noticed the egr diaphragm is a little cracked and faded. i have yet to pull it again so i can confirm if it does indeed have a hole in the rubber.

After replacing the TPS i had all codes clear besides 33.

Can a leaking egr diaphragm cause a vacuum like noise/symptoms while driving around? and a strange if a little high idle?

can a IAC valve give you such bad throttle driving around?

as i said it actually got better when i replaced the tps...but when i installed the new one, although the idle stuttering problem when away it still idle high, also it doesnt stutter as bad when driving around but still does.

so unplugged almost no symptoms. plugged in new one, symptoms return but far far less noticable.

would unplugging the TPS have a effect on vacuum leak or perhaps a egr problem?

 

The high idle you speak of is almost always a vacuum leak, air getting sucked into the intake threw a cracked vacuum hose, bad sensor, or the lower intake manifold.

Have you checked and replaced dry rotted vacuum hoses??

If you have additional air sucked into the intake, this will effect your throttle, as the added air is making the engine run lean. Fuel to air ratio, and the sensors and ECU are not adjusting to the added air ratio.

The "bellowing" sound you hear could be caused by the Air Pump Check Valve, which is located on the rear of the engine, on the cross over tube that connects the 2 heads together, Do you have smog tubes off the exhaust manifolds?

Or a problem with one of the EGR Valve Control Switches, that are located on the left above the valve cover. Do you have one switch, or 3 switches??
The first picture you posted is where those 3 plastic vacuum lines go to, from the Vapor Canister. Is the vapor canister cracked?? Are all lines connected??

 

so took my van to a mechanic today. They did a smoke test and a vacuum leak going to the map sensor. as well as a leak at the iAC from a bent gasket...

they called me and said it was fixed. it wasnt.

still bucking and missing...idling better. although almost died while reversing and leaving.

SOoo after a test drive i brought it back. They then found that i had Spark Plug Wire Crossfire.

i could believe it...they are cheap rockauto wholesaler that came in a beat up "Champion" box that literally looked like a either a waaaay beat up pass storage or a return.

and they fit horribly...

but i have since tried to seperate them really well and the symptoms remain....as well as have tried to locate the spark from the cross fire they said they saw. but yet to find it.

but any who......Are Denso spark plug wires any good for fords?

i have found spark plug wiring diagrams but not have the intake mani in the "Drawing".

Any one got any real life pictures they can share of the way they routed theirs a 351w efi e250??



so perhaps the air sucking noise i was hearing was just the intake?which is stock.

the box of spark plugs i got..that fit horribly and so the mechanic said is cossing a cross fire.

 

No you have a vaccum leak. Did you say that when the HVAC fan is on that air switches from the dash or the defrost all on it's own? If so you need to remove and inspect the HVAC controls for a broken vacuum line.

 

first let me just say I appreciate you guys helping me you and sorry for not responding to each one of you.

Conanski, I had took my into a mechanic. They hooked up a smoker tester and did find 2 vacuum leaks.

It doesn't really switch to defrost it will stay at the setting I put it at..if that setting actually kicks on the fan or not is a 50/50 and I have tried to feel If it's just switching to defrost it's not.

Also it does not blow cold but will blow hot....when it blows.

Also with the van off when I move the ac controls around I can hear a almost gurgle sucking sound.

Would hooking a smoker tester to the intake(hopefully they tried other) blow smoke out a hvac leak?

Would a leak in the hvac affect drivability even with the ac off?

After reading this would you give this mechanic another chance?

The spark plug wire holder/separators are all gone and broken. So my spark plug wire are a little messy. I haven't had the cash to get my motor craft plug wires yet.

So it could just be a crossfire...

 

Mechanic said he fixed my vacuum leaks. Although I dunno if he only hooked up a smoke tester to the intake ports or if that would show a ac leak or not.

 

So as it turned out. It was my PCM. Mechanic finally found it. Replaced it. Bam....

Now for my ac. Thank you for all your help guys