Ford guys let me know what you think. TIA

[demarpaint]

Below is what was going on, the bogging is gone, the engine starts on the first try now. Sometimes when the idle comes down it will surge on the first start of the day, but that has gotten better too, it was doing it more often.

Now on a warmed up engine restart I get a surging the goes from about 400 rpms to just under 1000 rpms, and it will continue to do that until I touch the gas. I have gone thru everything. I had the issue below, and FI cleaning helped. Can these injectors still be dirty causing the warm engine restart surge? I had two mechanic buddies go thru it and they find no codes and no vacuum leaks. I read up on it on different Ford message boards and the surge is a common problem with hit or miss success in fixing it. I did a complete tune up and this thing runs strong has a nice idle when it isn't surging. Changing out TPS and IAC did nothing, MAP sensor did nothing, Coolant and ACT sensors did nothing. We even tried another ECM, same thing.

I installed the spacer plate below the IAC which did nothing.

As always thanks.
-------------------------------------------------------------

My 88 E-150 4.9L is giving me some problems. While crusing and slightly backing off the gas the engine feels like it is bogging down, as soon as you hit the gas the problem resolves itself, it is quiet annoying. There are no codes, I did a high pressure FI cleaning via the fuel rail with no luck, along with a bottle of Amsoil PI. It almost feels like when you take a small 1 cyl engine and ground it to shut it off, then quickly remove the ground just before it cuts out, only a very very fast hesitation or bog. The engine doesn't stall out, and if you hit the gas during this bogging it has tons of power! There is an occasional tiny miss at idle, compression is strong and in spec, the engine has just under 70,000 miles on it.

I am 100% certain there are on vacuum leaks.

The truck has plenty of power. I'm thinking plugs wires cap rotor? I will probably replace if you guys think its a good idea, but they don't have much miles on them, fuel pressure is spot on, filter is new.

Suggestions?

TIA
Frank D

 

[DieselTech]

Vaccum leak

 

[crazyoildude]

Did you try cleaning the throttle body and maybe putting techron in the gas tank sometimes that helps, actually it helps more than sometimes..
On many occasions its the simpe things... Good Luck keep us posted

 

[jmac]

Throttle body and or IAC/ISC port cleaning may be the most likely fix. Also the ISC is a little stepper motor, if it is bad a lot of time you can tap on it when it is exhibiting symptoms and if they stop, you know you have to replace it again, every once in a while even new ones can be stuck and bad.

You can also ohm it to test it, but may not show intermittent trouble.
http://www.aa1car.com/library/idle_speed_control_valve.htm
http://www.justanswer.com/questions/ved8-88-5-0l-idle-not-stable-ranges

 

[DieselTech]

Vaccum leak

 

[pcfxer]

Check electrical circuit and TPS...also re-seat the chassis electrical grounds and clean it all up.

 

[mechtech2]

Bogging down when you let off the gas?
I never heard of that one, but maybe it's a trans problem - a lock up converter thing or dirty/worn trans innards causing some other anomaly.

One engine thing you should do is clean the TB bore and plate really well. Get the whole area with a rag and solvent as clean as you can.
Also, check your TPS for accuracy and smoothness.
Spray clean your MAF with dedicated MAF cleaner.

 

[demarpaint]

This is a 5 speed stick, the bogging issue is no longer an issue. It is a surge problem upon restarting a warmed up engine. Myself and 2 mechanics went thru this thing from top to bottom we are are certain there are no vacuum leaks. All connections, sensors and the ECM check out OK. It has no MAF sensor, it has a MAP sensor and that was swapped out with a friends along with the TPS and IAC. Each time we changed a part I cleared the codes and took her for a ride, in fact we even swapped the ECM, the condition is exactly the same. The Throttle body is spotless.

The bogging was related to injectors because after a high pressure cleaning and a few tanks of Red Line FI cleaner that along with some cold start issues went away.

Since 3 of us have gone through this thing on 3 different occasions and draw a blank, the only thing I can think of is an injector issue? Should I run a 4th bottle of FI cleaner through it, or do another high pressure cleaning via the fuel rail again?

 

[ADFD1]

Sounds like the horror I went thru with my buddies F-Series truck. His surges too, mechanic had it for weeks, we tossed all kinds of goodies at it before we turned it over to him. It runs well, but still surges if you flip the A/C or Defroster on. The mechanic told my buddy to live with it, a tap on the gas seems to straighten it out. I searched the Ford boards and it seems to be common with the older EFI Fords. Let me know what happens with yours.

 

[mechanicx]

Originally Posted By: demarpaint
This is a 5 speed stick, the bogging issue is no longer an issue. It is a surge problem upon restarting a warmed up engine. Myself and 2 mechanics went thru this thing from top to bottom we are are certain there are no vacuum leaks. All connections, sensors and the ECM check out OK. It has no MAF sensor, it has a MAP sensor and that was swapped out with a friends along with the TPS and IAC. Each time we changed a part I cleared the codes and took her for a ride, in fact we even swapped the ECM, the condition is exactly the same. The Throttle body is spotless.

The bogging was related to injectors because after a high pressure cleaning and a few tanks of Red Line FI cleaner that along with some cold start issues went away.

Since 3 of us have gone through this thing on 3 different occasions and draw a blank, the only thing I can think of is an injector issue? Should I run a 4th bottle of FI cleaner through it, or do another high pressure cleaning via the fuel rail again?


I think it is probably the injectors based on what you said or at least clogged injectors can cause hot start problems. You could try cleaning them at the rail again. Have you checked fuel pressure and checked the fuel pressure regulator for leaking? Maybe check the injectors' resistance, and inspect the the injector wiring. On GM you can do an injector balance and coil test and I think Fords too but you need the test equipment. But have you checked out the ignition system too, wire and coil resistance and plugs? I'm not real familar with fords but older Fords are funny they use the distributor hall sensor to time the injectors and ignition and they have troublsome ignition modules but I don't think that is the problem here.

 

[demarpaint]

The pump and pressure regulator were checked and it was determined they were OK. The filter is new, coil is good, plugs cap wires and rotor are new. The ignition control module is new as well. I had a mechanic clean the injectors at the rail, and cold starts improved, from starting and stalling once when cold, to starting and running on the first try. An interesting side note was after the first start of the day, after about 1 minutes running it would start surging until I tapped the gas. If I didn't tap the gas the surge wouldn't stop. That condition seems to have stopped.

I followed the rail cleaning with 3 bottles of Red Line FI cleaner. About a month before the problem I ran a bottle of PI Fuel Injector cleaner. Compression is spot on, and once warm and running, and not surging it runs great, LOL.

I have the equipment to clean the injectors via the rail myself, just not sure on the exact procedure, I haven't used the equipment in over 15 years. IIRC I have to disable the pump and run it off the can via the Schrader valve. Not sure what to do with the Fuel pressure regulator valve, and if there is any other part of the process I'm missing. I will look into that.

Thanks

 

[duaneb9729]

Could there be a small vacuum leak in the brake booster?

Didnt Ford have a tin can looking thing that held extra vacuum, could that have a pinhole leak?

 

[demarpaint]

I checked probably 3 or 4 times myself, and 2 mechanics verified it has no vacuum leaks. I'm really thinking injectors, after all the van is 1988 low miles, and saw little use. Every thing is clean as a whistle.

 

[mechtech2]

Injectors are a possible problem for sure.
And remember that they also have 'O' ring seals that may be leaking here and there.
A hidden vacuum leak is in the brake booster system.
Also under the dash for the vent controls.

 

[demarpaint]

I've ruled out the vacuum booster, and was spraying around the injector O rings with carb cleaner to see if there was any change in how the engine ran, and noticed nothing. So I am "reasonably sure" there are no vacuum leaks.

How would you deal with the injectors, they were cleaned about 500 miles ago at the rail, and a total of 4 bottles of FI cleaner was added to the gas in the last ~ 1200 miles. Do I do a rail cleaning again, or try another bottle of FI cleaner or three? I'm just about ready for an oil change and was hoping to resolve this issue before the OCI, but the way things are going I have doubts.


Another question, since the TPS is non-adjustable, can I elongate the holes that the screws go through and fool around with that to see if it matters? I have 3 TPS sensors here, none of which made any difference, but they were not modified. Voltage at the TPS is within spec. So its a long shot!

Thanks!

 

[wander2039]

Does your van have vacuum controlled HVAC controls? I had problems with idling on a Ranger once and they had to replace a line in the dash.

 

[demarpaint]

Yes there are vacuum controls, which were checked OK but the mechanics. I'll have another look for myself, I'm pretty confident in these guys, but who knows?

I still think it is injector related. I'm debating doing another cleaning via the rail, or maybe a two bottle treatment of the Red Line FI cleaner?


Keep the suggestions coming. Thanks

 

[OVERKILL]

Originally Posted By: demarpaint
I've ruled out the vacuum booster, and was spraying around the injector O rings with carb cleaner to see if there was any change in how the engine ran, and noticed nothing. So I am "reasonably sure" there are no vacuum leaks.

How would you deal with the injectors, they were cleaned about 500 miles ago at the rail, and a total of 4 bottles of FI cleaner was added to the gas in the last ~ 1200 miles. Do I do a rail cleaning again, or try another bottle of FI cleaner or three? I'm just about ready for an oil change and was hoping to resolve this issue before the OCI, but the way things are going I have doubts.


Another question, since the TPS is non-adjustable, can I elongate the holes that the screws go through and fool around with that to see if it matters? I have 3 TPS sensors here, none of which made any difference, but they were not modified. Voltage at the TPS is within spec. So its a long shot!

Thanks!


NO. As long as the TPS is within range (between .60 and 1v with the key on, engine off) you are fine.

Silly question: What colour are the injectors? I can't remember if this engine has 14lb/hr injectors or 19's..... If it has 19's, I 've got something I'd like you to try.

 

[demarpaint]

Originally Posted By: OVERK1LL
Originally Posted By: demarpaint
I've ruled out the vacuum booster, and was spraying around the injector O rings with carb cleaner to see if there was any change in how the engine ran, and noticed nothing. So I am "reasonably sure" there are no vacuum leaks.

How would you deal with the injectors, they were cleaned about 500 miles ago at the rail, and a total of 4 bottles of FI cleaner was added to the gas in the last ~ 1200 miles. Do I do a rail cleaning again, or try another bottle of FI cleaner or three? I'm just about ready for an oil change and was hoping to resolve this issue before the OCI, but the way things are going I have doubts.


Another question, since the TPS is non-adjustable, can I elongate the holes that the screws go through and fool around with that to see if it matters? I have 3 TPS sensors here, none of which made any difference, but they were not modified. Voltage at the TPS is within spec. So its a long shot!

Thanks!


NO. As long as the TPS is within range (between .60 and 1v with the key on, engine off) you are fine.

Silly question: What colour are the injectors? I can't remember if this engine has 14lb/hr injectors or 19's..... If it has 19's, I 've got something I'd like you to try.


The injectors are gray.

 

[OVERKILL]

Darn, those are 14's. If it had 19's, you could score a 4-hole set from a Modular 'Vic at the wreckers. They have a much better spray pattern.