[Streetgang]

Ok so heres the deal. On my daily driver a 93 w/302 mostly stock with a E4OD.....with a slight load on the engine...at light to moderate throttle I am getting a sort of surging......like as if I was modulating the gas pedal up and down slightly.....thats about the best way I can describe it. It dont seem to matter much if the truck is warmed up or not, but the ambient temp may have something to do with it.....I dont remember it happening in the summer????

I already checked for codes....but got 11's. I also removed the IAC and gave it a good douching with TB cleaner, but didnt notice any diference..I even switched the brand & octane rating of fuel I use........but I can still feel it.

It is intermitant....meaning I can not ALWAYS make it happen exactly when I want.

Anyone got any ideas?
Thanks in advance!

 

[rvcam]

I would try simple stuff first. Like a good tune up: plugs, wires, fuel and air filters, cap, rotor, and o2 sensor(s). Maybe run some injector cleaner through it. Can you make it do it when parked? If so try checking fuel pressure while it is doing it. Could it be a dragging of some kind? Maybe have the transmision serviced.

Don't know if that helped and you can probably rule out or have already done all of that but those are the things I would try if you you haven't yet.

 

[Slickerthanyou]

Hopefully not..

I had that same thing then my FDM stop working. After a new one it hasn't happened since. I had this problem for a while maybe 8 months or so and a couple times I couldn't get it started till next day after it sat all night. But I thought you already put one in? - bob

 

[91nite351]

you check for vacuum leaks, even a slight intake leak maybe. spray everything down with it running with carb cleaner and see if you get a change in idle. i have had that happen with so many stangs, and my 91 351 in my nite would do the same thing with my intake gasket leak.

 

[Streetgang]

I had that same thing then my FDM stop working. After a new one it hasn't happened since. I had this problem for a while maybe 8 months or so and a couple times I couldn't get it started till next day after it sat all night. But I thought you already put one in? - bob

You got me on this one.....what is the FDM????

you check for vacuum leaks, even a slight intake leak maybe. spray everything down with it running with carb cleaner and see if you get a change in idle.

I was thinking the same exact thing, but have not got around to that one yet.
Just so you guys know.....90% of the "tune-up" maintenance stuff on my truck is new or almost new (I over maintain everything)......and I wanted to let you know that yes I can do it with the truck in park, just not as easy or at will, but I can get it to happen.
Another thing......I also change the purge valve solinoide.....on advice I found in the forums.....I thought it helped ...for a while.

 

[rvcam]

You got me on this one.....what is the FDM????

I was not sure eather so I googled it. This is the only thing I found that it could be:

"Fuel Delivery Module


The fuel delivery module is an integrated system that combines the fuel pump, reservoir and sender assembly into a single module that is positioned in the fuel tank. The fuel pump is situated inside the module reservoir and supplies fuel through its manifold to the engine and to the module’s jet pump which continuously refills the reservoir.

Mounted to the top of the fuel tank, the spring loaded Fuel Delivery Module from Visteon provides continuous bottom referencing for the fuel pick-up and sender assembly."

So basically it is the fuel pump and sending unit assembly if by FDM he means fuel delivery module. So if it is that you should see a drop in fuel pressure when it surges.

 

[green94]

Im haveing a similer problem mine will surge sometimes and also ping under a load.I brought it in awile back to get it smoged and it past they found nothing wrong and i paid them to run it on a scope before the smog to try to find a problem.Does yours do it in all gears ? Awile ago before this problem a had a surge mainly on the freeway wile under a load .It later started shifting hard (trouble mode) it took it to a trany shop and it was the TCC torque converter clutch going out needles to say the old trust E4OD was due for a rebuild $$$.The coverter clutch would not dissingage under a load on the freeway so it would stay in high gear and bog the engine and cause it to fight to keep speed.I have,nt been drive my Bronco much lately im going to try to take it to a shop this week if posible .If i do i will post the problem if they find it.Brian

 

[Slickerthanyou]

I was not sure eather so I googled it. This is the only thing I found that it could be:

"Fuel Delivery Module


The fuel delivery module is an integrated system that combines the fuel pump, reservoir and sender assembly into a single module that is positioned in the fuel tank. The fuel pump is situated inside the module reservoir and supplies fuel through its manifold to the engine and to the module’s jet pump which continuously refills the reservoir.

Yip that's it.

So basically it is the fuel pump and sending unit assembly if by FDM he means fuel delivery module. So if it is that you should see a drop in fuel pressure when it surges.

I didn't check that as My pump just died- I had power all the way to the harness- Replaced it- bob

 

[Streetgang]

Im haveing a similer problem mine will surge sometimes and also ping under a load.I brought it in awile back to get it smoged and it past they found nothing wrong and i paid them to run it on a scope before the smog to try to find a problem.Does yours do it in all gears ? Awile ago before this problem a had a surge mainly on the freeway wile under a load .It later started shifting hard (trouble mode) it took it to a trany shop and it was the TCC torque converter clutch going out needles to say the old trust E4OD was due for a rebuild $$$.The coverter clutch would not dissingage under a load on the freeway so it would stay in high gear and bog the engine and cause it to fight to keep speed.I have,nt been drive my Bronco much lately im going to try to take it to a shop this week if posible .If i do i will post the problem if they find it.Brian

Mine does it mostly at speeds under 30MPH.....and is most evident at speeds under 15 or 20. I can get it to do it in N or P also........

 

[Wolf_Spyder]

I use to have this problem. I went to the junk yard and bought a MAP sensor. I paid $5.oo

The problem is gone. It is a small black box looking thing on the firewall.

 

[rhetor]

Test the TPS sensor for a smooth reading from idle to WOT.

You could try running an EGR blockoff plate. If it makes a difference, leave it. If you get a code, drill a 1/4" hole in the plate.

 

[green94]

Hmm i took mine to a shop yesterday and they played around with it .They said every thing checks out ok.I even took one of the mechanics for a ride up a good size hill we have on the freeway and let him hear some pinging.They keeped it over night and ran some more tests on it all they could say is run higher grade (octane) fuel in it .They said it could be some carbin build up i guess i will just keep running it.Brian

 

[Wolf_Spyder]

I think you need to find a new shop. My younger brother is an ASE Master Mechanic. I hear a lot about morons trying to be mechanics. It seems if you can't do factory work you should try to be a wrench turner.

Find another shop. Find a mechanic who knows what he is doing.

 

[NHBronco]

run higher grade (octane) fuel in it.

You should check your timing. Sounds to me like you are running too much advance on it. "Pinging" is frequently caused by either of those two things, cheap gas or too much advance.

IIRC the distributor has a TFI (?) module attached to it. I think it means "thick film integrated". I believe it is intended to act as an old fashioned vaccuum advance while the engine is accelerating or is under a load. There is a sensor inside the distributor that can get covered with stuff that should be cleaned off.

I believe that the 302 of that year had a knock sensor that was designed to retard the timing when it sensed knock. That seems like a fairly complex system to me which always makes me suspicious.

I'm sure someone will either correct me or fill in the missing information.

Does anyone know what the correct base advance should be and what the total advance should be?

 

[rhetor]

I'm not sure if that motor has a knock sensor, but it most likely does. The knock sensor is merely a microphone screwed into the block. The computer reads the mic and checks for a certain noise that it recognizes as knock. This does help to safe guard against too much timing advance for the fuel.

You're sure its pinging right? I don't mean to sound like a jackass, but you didn't mention any pinging in your first post. Could be running very lean. This would cause possible pinging, and misfire, hence the bucking. If it was a bad O2 sensor, it should run fine at WOT, as well as idle, but when you're light throttle cruising it'll run like crap.

How does she do at WOT and idle? Is this an intermittant problem, as in one or two days out of the week it'll run fine, and the rest of the days it'll run like a chevy?



Try not to bash a mechanic because they had trouble finding the problem. I know a couple ASE certified mechanics that would be absolutely lost without their modis II scanners.

 

[Wolf_Spyder]

I guess I'm second hand bashing... I hear all the stuff my youngest brother has to say about the guys in the Newark / Columbus area. He likes his scanner... but he doesn't need it to do his job. He can listen to the motor and have a good Idea of what is going on. Of course like most wrench turners he hates Fords.

 

[bigric]

When my EGR valve went bad it acted exactly like this--a lot of flutter on light acceleration.

 

[93BIGBLACKBRONCO]

Try checking the Canister Purge Solenoid, It opens to burn off fuel vapors from charcoal canister. When activated ECM leans out mixture, it comes on at part throttle after warmup.
Mine had one vacuum port broken off so when open vacuum leak and leaned out by ECM Caused big hesitation on hills.
No codes and No vacuum leak at idle only when cruising.
It's connected by vacuum line from manifold near throttle body to charcoal can, has 2 wire plugin on one end and vacuum ports on the other.
Check fuel pressure regulator too.

 

[Gacknar]

Test the TPS sensor for a smooth reading from idle to WOT..

:stupid

http://fordfuelinjection.com/index.php?p=30

 

[Streetgang]

:stupid

http://fordfuelinjection.com/index.php?p=30

Well it is as far as I know the original TPS, and I am pushing 91,000 miles now. I guess I will have to read up on exactly how to test the TPS.
I changed the fuel filter yesterday (it had been like like 1.5 years and like 16,000 miles, and quite a bit of black sh!t came out of it), and this morning I dropped in like half a can of Sea-Foam to the fuel tank. It seems to have helped a bit. I think I will get my best bang for the buck by giving the TB a real good douching, and replacing the TPS with a new one (if the original one tests good, I can keep it as a back up.

Anyhow.....the truck is running perfect today.....no surging at all, and the engine feels strong as hell like always......and I am still compiling a list of things to do this spring......starting out with a new set of JBA headers, a 3G, and a bunch of drive-line work!

I can only go just so long before I have to do some sort of mod or service to my Bronco!