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I haven't posted on the forum before but have been reading/referencing it daily since acquiring my 91' E350 (351w) a few weeks ago. It's been incredibly helpful.
While getting ready to to replace my throttle body position sensor, I found the below pictured connector hanging loose near my throttle body and cannot figure out for the life of me where it goes. It appears to be coming out of the same wire loom as the connector that goes to the engine coolant temp sensor. Any help would be appreciated in identifying what it is and where it's supposed to go.
Can you take a picture zoomed out a little so we can get a better reference point?
What are the wire colors to that connector?
That is a male connector and on my 88 E150 with a 5.0, the only male connector near the throttle body goes to the TPS
Thanks
Anna
Can you take a picture zoomed out a little so we can get a better reference point?
What are the wire colors to that connector?
That is a male connector and on my 88 E150 with a 5.0, the only male connector near the throttle body goes to the TPS
Thanks
Anna
Thanks, those pics make it much easier to get the general idea of what the connector might go to.
Well I have looked at my 1988 diagrams and cant find any information yet, There were some changes between 88 and 91.
Can you clean and verify the wire colors on the three wires going into the connector? Maybe we can trace it down by using the wire color coding or PCM pin out diagrams.
Is there a sensor on the air breather box?
You are sure it is not for the TPS?
Also what type of transmission is in your van?
I have several connectors that are unused on my 88 but they are female connectors and I believe were for a future ABS system which was not used in 1988 on the E150s
I was going to send a PM to subford as he would probably know what the connector goes to from the wire colors but couldn't get one through.
I was typing a reply when you replied so this may seem out of order. We nee to find a pcm pin out diagram or a wiring diagram that matches your 1991 E350 and then we could just look up the wire colors and see what they go to. As I said earlier Ford made some changes between 88 and 91 on the vans so that may be why I cant find anything in my 88 Ford service manual. I would want to know what the connector goes to.
What do you plan on doing with the van? My 5.0 and your 5.8 are not that much different though I would prefer the 5.8 for the extra power.
What are the power issues when driving?
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Do you now if the emissions has been disconnected from your van? Does it still have the air pump connected?
I am not sure how close the PCM pin out is to your 91 E350. The thread was started for a 1990 truck with a 4.9..
There is one other connector in that area on my van but I doubt it is what you are looking for. My AC compressor clutch connector has a short pigtail connector on it and one end looks similar to the one you show.
I plan on using the van as a combo of daily driver (I ride my bike to work so really just for running errands here and there) and camping. It’s a 15 passenger van so pretty long. I’m going to keep the first row of bench seats and then throw a bed and window ac in the back and we are hitting the road this summer.
So far I’ve replaced the plugs, wires, dist cap, rotor, map, ignition coil, air pump (old one was seized), thermostat, both coolant temp sensors, pcv valve, and some old vacuum lines I found that were in rough shape. Took it on a test drive and everything was running great until it was on for about 30 minutes. After that while in drive it would want to die when giving it gas coming from a stop.
So now I’ve replaced the fuel pressure regulator and the ignition sensor attached to the distributor. I also plan on checking the timing and replacing the fuel filter in the near future. Which brings me to the other issue. The fuel selector valve was removed by the previous owner and the front tank completely disconnected. I’m waiting on a new fuel selector valve to come in the mail but am wondering if that was messing with the fuel pressure. Anyways I didn’t say all this earlier because I figured it was too much for this thread as I originally was asking about that connector lol.
My next steps after I get everything hooked back up and timing set is to test fuel pressure. Also I know it’s controversial but I don’t have to do smog testing at all and am planning on swapping the aft most cat for a muffler and jamming a pipe through the front one to clear it up. I don’t mind paying for all the other parts because I figure if they weren’t all worn out they were well on there way anyways. I do really want to find the cause of the power issue when giving it gas though.
I do still have emissions stuff and recently replaced the air pump as the old one seized and snapped my serpentine belt.
I also have a new throttle position sensor sitting in my garage I’m thinking of throwing on but don’t really feel like taking out the throttle body to do so unless I really need to.
And before anyone asks, no I have not run codes but might soon if I can get my hands on a cheap code reader.
I am an idiot. It is the other half of the throttle body position sensor 🤦🏻 Once I get my timing set and fuel hooked back up etc I’ll start another thread on if it all works or not.
In the mean time I appreciate your help and am sorry for wasting your time on this one.
Don't feel bad, I am very good at being an idiot myself! Don't worry about wasting my time. My doctor has me stuck at home for the most till I can get a vaccine. On top of that when I help others on our older vans, I learn more about mine!
I will one day convert mine to a camper. That extra length you have will be great for a camper.
How long have you owned the van and do you know the folks you got it from?
How many miles are on it?
There are 3 tests I do these days on vehicles I am thinking about buying or before I spend much money on them...,
1- compression test.
2- Combustion gas test
3-Vacuum test.
Many people think the vacuum test is for old cars but it works the same on new cars and can tell you a lot about the condition of your engine. A vacuum test can also tell you if you have a clogged cat...
In the past when testing my engine for some issues and had the dog house off, driven around with a vacuum gauge and fuel pressure gauge connected so I could get actual readings in real time.
I know you said you changed the FPR but you could still have fuel pressure issues after the van has been running a bit.
Another thought might be when the engine is cold the controls are running in open loop and the system goes into closed loop after the engine is close to being up to temperature In closed loop the PCM trims out the fuel for better mileage. Check codes... Not all sensors will throw a code on these older vans though. I was having some occasional issues and a surging idle when restarting after the engine had heated up but no codes. I changed the IAT, ECT, EGR vacuum solenoid, MAP and IAC and all the problems went away. I am not positive which sensor was bad though. I started the engine between each sensor change to make sure everything was still working but didn't test drive between each one.
Changing out old sensors and hoses is a great idea on these older vans, especially sensors or components that have rubber diaphragms in them.
If you remove the emissions parts, store them away in case you need to reinstall them one day.
As to the emissions, I still have all of mine except I have a single cat instead of 2.
I want to change my timing chain and water pump because I have 145k on mine but am afraid of those bolts breaking that run through the timing cover!
There is a test for the timing chain slack and I need to do it. Clean your timing marks and pointer and move turn the harmonic balancer/crankshaft clockwise till the timing marks line up on 0. With the distributor cap removed, slowly move the crankshaft counter clockwise until the rotor just starts to move. Repeat if you need to but you are looking for less then 7 degrees slack. 7 or more then you need to change it.. I think if mine is at say 5 to 6 I would go a head and change the timing set when I had time. Again it can turn out to be a big job if one or more of the bolts break. BUT again sometimes they will come right out...
If you look online you can find instructions to check the codes without a reader. You just need to install a jumper and can read the flashing CEL below the light switch..
Also if you have remove the throttle body then it is a great time to clean it. I'll share a tip I learned with mine. There are 2 vacuum line that connect to the throttle body ( at least on the 5.0) and there was crud built up inside one of the passages. It was a hard material.
When you take yours off you will clearly see what I am showing in the pics below. I marked one of the passages in red. You can see the plug (there is a name for them but I forgot) I would have removed them and replaced them if I had had them but I didn't..
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here you can see where that passage is cast. The plug is on the bottom side..
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Another look and you can see a little slot..
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Inside that little slot is where I noticed the problem. There was some hard crud stuck inside the passages and in the slot.
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I managed to break the it up in small enough pieces that I got it to fall out through the vacuum port connection and then flushed it with cleaner several times. SO just watch out for that when you are cleaning the throttle body!
I’ve only had it a few weeks. I’m the third owner. It was originally a church van and then later purchased by the older guy I bought it from. He used it once a year to drive to an annual camping trip with his buddy and slept in it. 75k miles on it.
It’s a massive project and maybe a bit more than I expected it to be. I did get it started back up again today after installing the new duel tank selector. Once I managed to get it idling and warmed up a bit I checked the timing and was surprised to find it at around 5. Not sure why it was moved to that low and suspect it’s a major contributor to how it’s running.
While it was idling I also discovered the radiator was pinholed and losing coolant. Decided to swap in a a new radiator and fan clutch while I was at it as it had been running a little warm on the dash.
Im gonna mess with it more tomorrow. I need to do a big write up and everything I’ve been doing to it when I get some time! Hopefully I’ll have it running right soon as we have a pretty big camping trip planned in May!
Yes, please follow up with processes and solutions you may find. I gave my 1989 to my older brother that is fighting a rough running issue, but still have the 1990 shorty that my son has pretty much abandoned. I keep hoping that I'll stumble across the answer to it's weird shifting points issue. So, yeah post up. And good luck.
I’ve mostly figured it out but it hasn’t been cheap. With it being a 30year old van I figured it was time to change just about every sensor that has anything to do with fuel/air. So throttle body position, EGR, fuel pressure regulator, both temp sensors, cleaned the throttle body, set timing, rotor/plugs/cap/wires, idle air control, high pressure fuel pump, o2 sensor, got rid of cats, fuel and air filters, the small canister solenoid that connects to the throttle body, some vacuum lines, probably more in forgetting. It’s running really well now but does seem to need a little push on the pedal to get it to start well. Runs down the road fine. Next up on my list is the passenger side exhaust manifold is leaking and dropping the rear fuel tank and replacing the sending unit and pump. I’m also going to run sea foam through the brake booster line to help the injectors. Also trace out the rest of the vacuum lines and replace any that look old.
My strategy has been to replace as much as possible now with the hopes of many trouble free miles to come. I also bought a van that wasn’t maintained great and that had been sitting for many years. If you are familiar with your vehicle history and know it’s been maintained maybe it would be better to run codes and find exactly what needs to be replaced rather than changing everything like me. I’m going to do some more extensive test driving next week when I have some time so we’ll see if it’s actually fixed then but definitely is idling much much better now.
Oh also I just remembered that while I had the throttle body off I took the time to route my wires more carefully to prevent potential cross firing.
