1993 3.0L Aerostar with starting issues.

[chris9999]

Hi, I purchased this vehicle from the motor pool of a local government body.
The vehicle was very inexpensive, so I don't mind spending a little bit. But I also don't want to be pumping
money into a hole.
The inside is a mess but usable. The underbody is beautiful. The exterior is a bit rough but not too bad.
I has 150k miles on it.

The first thing to note is that the cat converter has been hacked out with a sawzall,
so it is loud.

Starting: I hear the fuel pump run for just a brief period. I get a pop-off after a few revs.
I stop cranking. I crank again and it pops off a bit more.
I keep doing that, probably a dozen or more times and eventually it will fire and run smoothly then die.
And if I keep at it I can get it to run, particularly if I flutter the throttle a bit and keep it off of minimum idle.
When it isn't smooth it sounds like a drag racer engine, not in loudness but in hit/miss nature.
When it is smooth it actually sounds pretty good.

The intake: The molded intake hose has holes in it. I tried looking something up at the local auto parts stores and
nothing comes up except generic hoses. What do you all do?

I wanted to get as far as I could to see if it is worth doing the cat replacement or whatever. And when the
engine is running smooth it actually sounds good and it revs good. I'm interested in your thoughts.

 

[chris9999]

Hi, I purchased this vehicle from the motor pool of a local government body.
The vehicle was very inexpensive, so I don't mind spending a little bit. But I also don't want to be pumping
money into a hole.
The inside is a mess but usable. The underbody is beautiful. The exterior is a bit rough but not too bad.
I has 150k miles on it.

The first thing to note is that the cat converter has been hacked out with a sawzall,
so it is loud.

Starting: I hear the fuel pump run for just a brief period. I get a pop-off after a few revs.
I stop cranking. I crank again and it pops off a bit more.
I keep doing that, probably a dozen or more times and eventually it will fire and run smoothly then die.
And if I keep at it I can get it to run, particularly if I flutter the throttle a bit and keep it off of minimum idle.
When it isn't smooth it sounds like a drag racer engine, not in loudness but in hit/miss nature.
When it is smooth it actually sounds pretty good.

The intake: The molded intake hose has holes in it. I tried looking something up at the local auto parts stores and
nothing comes up except generic hoses. What do you all do?

I wanted to get as far as I could to see if it is worth doing the cat replacement or whatever. And when the
engine is running smooth it actually sounds good and it revs good. I'm interested in your thoughts.

More: I took the air intake pipe completely out, unplugged the mass air flow sensor.
I did a bit of cursory cleaning on the throttle body but it seems to be build into the intake so I can't take it out and clean it.

But! Starting it with no MAF and no intake it fired right up! So I think those holes in the intake are a real issue.

 

[BrooklynBay]

Is the oxygen sensor missing? Are the wires cut? I suspect that there are multiple codes with an illuminated check engine light.

 

[chris9999]

The check engine light flashes on when starting (it's not burnt out) but is not on when running.
I think the O2 sensor is still there. I can't swear that the wires are intact.

 

[Josh P]

Start by cleaning or replacing the maf sensor. The intake tubes are getting hard to find new. If I was replacing that tube, I'd either use a long piece of high temp rubber tube or abs plastic.

 

[BrooklynBay]

I saw aftermarket tubes in Autozone. Did you check EBay?

 

[410Fortune]

What about patching the holes with silicon and some hood duct tape wrap the whole pipe? At least might help for testing

It sounds to me like a weak fuel pump issue after you solve the big holes in the intake tube

Any air that enters the intake after the mas sensor makes it very difficult for the computer to adjust fuel and spark it is called “un metered air” so get those leaks fixed first thing.

 

[chris9999]

Hi, an update!

I'm still running without an intake tube. But I haven't been running much.

I noticed that I had about two quarts more oil than expected.
So I investigated the auto transmission modulator valve and it did have fluid in the vacuum tube.
I replaced that. Changed the oil and the oil filter. I topped off the transmission fluid (about two quarts).

I still don't have a good intake and the sawed out cat converter is still gone. So it is a bit hard to start but it will eventually run.
The check engine light comes on. It is loud. All of that is expected.

But! I have another issue that probably is higher priority.

The transmission does not shift correctly. I was hoping it would get better after I sorted out the fluid level.
But apparently not. Reverse goes reverse. CircleD and D give some forward motion. 2 and 1 give forward motion.
Setting 2 appears to be a higher ratio than setting 1. CircleD and D both are like setting 1. In the 10-15 minutes I've
driven it, it has never automatically shifted while in CircleD or D. Both feel like they are stuck in 1.

I'm kind of hoping one of you folks will jump in and say there is some tube or sensor to replace, or a magic place to whack it with a hammer.
But if not, I think maybe my transmission is a goner.

 

[Josh P]

Did you verify the metal pin was present when you replaced the vacuum modulator? If that was the first fluid change the transmission had, keep a good pair of walking shoes in the van.

 

[chris9999]

Did you verify the metal pin was present when you replaced the vacuum modulator? If that was the first fluid change the transmission had, keep a good pair of walking shoes in the van.

I did find the pin and stuck it in the hole in the new modulator. It didn't seem like it had a solid landing spot in the transmission end. The modulator seated fine, but I kind of expected the pin to have a receptical, in-place feeling. Is it possible I messed up the insertion?

 

[Josh P]

I did find the pin and stuck it in the hole in the new modulator. It didn't seem like it had a solid landing spot in the transmission end. The modulator seated fine, but I kind of expected the pin to have a receptical, in-place feeling. Is it possible I messed up the insertion?

The fact the transmission goes in 1st, that usually indicates the vacuum modulator or valve body. Some forum members have reported good luck with an adjustable modulator.

 

[chris9999]

Hi! another update

I discovered that the engine end of the intake tube was a rubber folded-over ring on top of a hard plastic ring of the end of the formed intake tube.

The formed end was crumbling away and mostly gone up to the first corrugation. So most of the that end of the tube was separated completely. . And the first two corrugations had spots worn through.

I took the rubber fold-over gasket with me to Lowes. In the department for tin chimney bits I found a plastic "reducer" from 4 inch to 3 inch. For me the 3 inch was exactly the right size to fit in my fold-over gasket and I later confirmed that the 4 inch end was very close to the size that would fit over the corrugations... but not quite. So I ended up taking some rubbery self-fusing tape and liberally taping the 4 inch end to the corrugations and over the holes in the corregations. Then I used some glue in a tube called "Flex Glue", also from Lowes, on the _inside of the big end to fill in between the 4 inch plastic and the remains of the crumbled plastic ring and first corrugation.

I let it all sit overnight then installed it. It has a bit of flexibility in the remaining corrugations and no longer has leaks.

The van now runs with the Check Engine light OFF!

Today I drove into town to a muffler shop and they put on a replacement catalytic converter and the necessary pipe bits.

As for shifting, I did re-seat the transmission modulator and I made sure the vacuum tube was clear. It has been shifting better. The shift points were pretty high but they have been coming down as I use it. So I am hopeful that some exercise will loosen things up a bit.

It's possible that I might have a vacuum leak which would keep the transmission modulator from having full effect. I don't have a vacuum gauge to measure the vacuum at the modulator. But, if I am thinking correctly, a lower vacuum would cause the transmission to delay shifting to a higher RPM.

Overall I am very happy. It starts right up, sounds much better with a whole exhaust in action, the check engine light seems satisfied. The intake leaks are managed.

I'd like to find a fan-speed knob and some interior door panels for the front and the side. And my rear door is complaining that it is open all the time. It needs new gas-props for the rear also. The headliner is disintegrating. It has some wobbles that come on around 65 mph which could be the old tires needing balance or maybe a bad shock. And the interior carpet looks like lots of years of spilled coffee. The bench seats are missing and I'm not sure that I care.

 

[chris9999]

Hi! another update

I discovered that the engine end of the intake tube was a rubber folded-over ring on top of a hard plastic ring of the end of the formed intake tube.

The formed end was crumbling away and mostly gone up to the first corrugation. So most of the that end of the tube was separated completely. . And the first two corrugations had spots worn through.

I took the rubber fold-over gasket with me to Lowes. In the department for tin chimney bits I found a plastic "reducer" from 4 inch to 3 inch. For me the 3 inch was exactly the right size to fit in my fold-over gasket and I later confirmed that the 4 inch end was very close to the size that would fit over the corrugations... but not quite. So I ended up taking some rubbery self-fusing tape and liberally taping the 4 inch end to the corrugations and over the holes in the corregations. Then I used some glue in a tube called "Flex Glue", also from Lowes, on the _inside of the big end to fill in between the 4 inch plastic and the remains of the crumbled plastic ring and first corrugation.

I let it all sit overnight then installed it. It has a bit of flexibility in the remaining corrugations and no longer has leaks.

The van now runs with the Check Engine light OFF!

Today I drove into town to a muffler shop and they put on a replacement catalytic converter and the necessary pipe bits.

As for shifting, I did re-seat the transmission modulator and I made sure the vacuum tube was clear. It has been shifting better. The shift points were pretty high but they have been coming down as I use it. So I am hopeful that some exercise will loosen things up a bit.

It's possible that I might have a vacuum leak which would keep the transmission modulator from having full effect. I don't have a vacuum gauge to measure the vacuum at the modulator. But, if I am thinking correctly, a lower vacuum would cause the transmission to delay shifting to a higher RPM.

Overall I am very happy. It starts right up, sounds much better with a whole exhaust in action, the check engine light seems satisfied. The intake leaks are managed.

I'd like to find a fan-speed knob and some interior door panels for the front and the side. And my rear door is complaining that it is open all the time. It needs new gas-props for the rear also. The headliner is disintegrating. It has some wobbles that come on around 65 mph which could be the old tires needing balance or maybe a bad shock. And the interior carpet looks like lots of years of spilled coffee. The bench seats are missing and I'm not sure that I care.

I forgot to say that I sawed a few short slots in the 3" end of my plastic reducer so that the band-clamp would be able to crunch it down on the intake tube. They were short such that the folded over rubber covered them.. no leaking. That seemed to work.

 

[Josh P]

I'm curious how it does when you get some miles on it

 

[BrooklynBay]

There are 4" X 3" Fernco couplings in the same store which are slightly different. They say clay pipe in the description so one side is a half an inch larger while the opposite side is the same size as what you have.

 

[chris9999]

Update:
I decided to replace the ignition tune-up parts: rotor, cap, plugs and wires. They are cheap, and can't hurt.
So I did that, some yesterday and the rest today. One plug on each side was much looser than normal. I didn't see any erosion of the threads or anything, but they were loose enough that it surprised me. The cap and rotor were definitely tired.

Also I ran into another vacuum line with an issue. This one is a large rubber tube which then has an adapter converting it to a stiff plastic tube. The stiff plastic end goes into a tee which goes into a canister kind of thing on the passenger side firewall. For the rubber end I had problems figuring out where is should go. The only unpopulated thing that looked the right size was an "upper" port on a two port thing coming out of the top of the driver side valve cover. So I plugged it in there.

Results: My vent/floor/defrost switch now sends air flow to vent/floor/defrost! so I'm happy about that. My vacuum gage says I'm running about 20-21 when idling... much higher than the 16-17 I was seeing. My transmission shift points are _not_ improved. In fact I would say it is shifting even higher. It shifts into 2 around 40 mph and into 3 around 50-55. It seems to reliably go into overdrive around 60 and has done that from the beginning. No big change in the way it starts and runs, not that I've noticed. No check engine light.

Plans and ideas: I think I will disconnect the battery for awhile. I'm wondering if something "remembers" the previous conditions and these changes have confused it.

Also, I'm wondering if the Aerostar has anything like the PSOM capacitor problem that the F150's of this era have? I remember driving a E350 van with a blank odometer (which my Aerostar does _not_ have) for awhile and it was in transmission "limp home" mode and it did strange shifting also. I was able to fix that by following directions on youtube to replace electrolytic capacitors behind the speedometer. I really don't want it to be the transmission itself. I'm not competent to get it out or service it, and I think the expense would probably spell the end of life for this vehicle.

 

[chris9999]

Update:
I decided to replace the ignition tune-up parts: rotor, cap, plugs and wires. They are cheap, and can't hurt.
So I did that, some yesterday and the rest today. One plug on each side was much looser than normal. I didn't see any erosion of the threads or anything, but they were loose enough that it surprised me. The cap and rotor were definitely tired.

Also I ran into another vacuum line with an issue. This one is a large rubber tube which then has an adapter converting it to a stiff plastic tube. The stiff plastic end goes into a tee which goes into a canister kind of thing on the passenger side firewall. For the rubber end I had problems figuring out where is should go. The only unpopulated thing that looked the right size was an "upper" port on a two port thing coming out of the top of the driver side valve cover. So I plugged it in there.

Results: My vent/floor/defrost switch now sends air flow to vent/floor/defrost! so I'm happy about that. My vacuum gage says I'm running about 20-21 when idling... much higher than the 16-17 I was seeing. My transmission shift points are _not_ improved. In fact I would say it is shifting even higher. It shifts into 2 around 40 mph and into 3 around 50-55. It seems to reliably go into overdrive around 60 and has done that from the beginning. No big change in the way it starts and runs, not that I've noticed. No check engine light.

Plans and ideas: I think I will disconnect the battery for awhile. I'm wondering if something "remembers" the previous conditions and these changes have confused it.

Also, I'm wondering if the Aerostar has anything like the PSOM capacitor problem that the F150's of this era have? I remember driving a E350 van with a blank odometer (which my Aerostar does _not_ have) for awhile and it was in transmission "limp home" mode and it did strange shifting also. I was able to fix that by following directions on youtube to replace electrolytic capacitors behind the speedometer. I really don't want it to be the transmission itself. I'm not competent to get it out or service it, and I think the expense would probably spell the end of life for this vehicle.

Clarification... the thing I plugged the loose rubber vacuum end into was the _only_ open port I found, and it happened to be the right size.

 

[BrooklynBay]

There's a vacuum diagram under the hood.

 

[Josh P]

transmission gears 1-3 are hydraulic with vacuum reference. Your Aerostar does have a psom which is used for speed signal for 4th gear and torque converter lockup.

 

[chris9999]

transmission gears 1-3 are hydraulic with vacuum reference. Your Aerostar does have a psom which is used for speed signal for 4th gear and torque converter lockup.

My shifting symptoms, what I notice anyway:

This is driving around on a road where people normally do 35 and then onto a highway where speed limit is 65. I'm trying to drive normally, not aggressively.

I start off from standing and rpm increases steadily. I'm expecting if I let off the gas at 20-25 mph it will shift. But it doesn't do that. If I get off the gas it stays in the same gear. So I mash the go pedal again and continue to increase rpm. I get up to 35-40 mph, the motor is getting a bit whiny, but still not shift even when I prompt for it. Eventually with enough RPM then it does a jolt shift up. I continue to accelerate and it does the same with less jolt (2x?) and I get a nice smooth shift at 60 which has the engine running in what seems like a nice RPM for basically the first time of the whole trip.

If I start off in 2 it drives smoothly up to where I start to feel like I should upshift, around 35. I put it in D and it downshifts a bunch. If I go to (OD) it doesn't do that downshift, but it also doesn't shift up until I get to a higher RPM. But eventually around 60 (very reliable) it is driving fine.

When decelerating from 60-65 things seem to go in a normal fashion until I get to about 45 and then I get a downshift with some discernible engine drag. I continue to slow down and I don't notice anything unusual from there to dead stop.

Any ideas or advice?