'88 2.3L wont idle

[mlcasey13]

So ive been searching this forum now for a week or so while trying different things on my truck. I just got a 88 supercab 2wd 5speed 2.3l for free. When i picked it up i put a new battery in it and it started up but wouldn't idle right. The PO said it had done that for some time but would always start back up. So after a 65mile drive home it still wouldnt idle. I have both the Haynes and Chilton manuals trying to troubleshoot this.

A more detailed description of the problem.
-truck will start but after a few seconds it starts to shake and the rpm drop and recover getting worse and worse until it cuts off.
-will always restart
-runs fine as long as your on the throttle
-cuts off once warmed up and will cut off when coming up to a stop
-stumbles when applying throttle but usually recovers and runs good.
-The sooner after a stall that you restart it the worse the stumbling is. So if you let it sit for a few mins it will idle fine for longer.

things ive done trying to fix it.
-new air filter, spark plugs, plug wire, distributor cap and rotor, new IAC, new FPR, new vacuum line to MAP, new vacuum line to FPR.
-Ive checked the resistance from the battery to both the body and the engine and it read 0 ohms with good continuity
-HP fuel pump does run
-PCV valve is good
-EGR unknown (dont think this would cause stalling seen plenty of cars with caked up egrs run but a LITTLE rough on idle but not stalling...I will probably check it anyway)
-Ive checked the fuel pressure and what I found is when the key is turned on while the pump is running the pressure is 40psi. As soon as the pump turns off the pressure goes away completely in just a few seconds. While running its about 33-35psi.

The two things I have come up with are either the check valve in the fuel line is bad or I have one or more injectors stuck open. I dont believe or see how the checkvalve could cause it to run bad while the HP fuel pump is running. Right now im leaning towards it being stuck injectors and will check them first thing tomorrow since the exhaust smells kinda strong.

If im missing anything obvious that I need to look at please tell me.

Thanks

mlcasey

 

[James86]

Does it have an IAC? I haven't laid eyes on a 2.3 in a long time...

 

[mlcasey13]

Ive already replaced the IAC with a new one just to be sure. I can hear air flowing through it.

Im really sumped Im thinking I should check the timing ignition timing just to make sure. Does anybody have a good right up on how to do that? I know ive heard all kinds of things about unplugging different things so I just want to make sure i do it right.

 

[cody93]

my 2.3 has the same issues, ive got it down to my intank fuel pump being the culprit. when bench testing it, it will work ok, untill it sucks in air and wont suck fuel afterwards unless being beaten arround or the pump is turned off and turned back on. i was thinking of rigging the pump into a 5gallon gas tank to do more testing.

 

[mlcasey13]

Ok so update time.

Its decided to hold fuel pressure now dont know what changed maybe operator error with the fuel pressure gauge. It didnt drop but like 20psi over night.

Pulled the coded and it showed a TPS problem and some emissions thing im not worried about. So I checked the TPS and sure enough it wasnt working. After a quick trip to the junkyard (bout 5miles away...lucky me) i didnt find one but got some other goodies including a MAP sensor, but Advance did have one TPS. I threw it on there adjusted the out put voltage to about .9 volts at closed throttle and reset the computer for 30mins.

To bad that didnt fix it and either did the junkyard map. I then checked my timing with the spout removed and it was running right at TC so I adjusted it to 10deg BTDC like the book said. Hooked the spout back up....still doesn't idle right. I did confirm the computer is adjusting the timing cause now it is like 25deg BTDC with the spout connected.

I guess next step is going to be check the egr and make sure it works. Also I may need to replace the hose going to the pcv cause idk if its sealing good.

Im going to try to drive it and maybe burn a little gas through it. Should I run some seafoam or fuel injector cleaner?

 

[LIMA BEAN]

Just for good measure pull the vacume line going to your brake booster and see if you smell gas. Your fuel regulator even though showing decent pressure could be on its way out and when they go the way its tied into the vacume tree it will blow fuel into your booster and run rich like crazy, i saw one that would hydro- lock the back 2 cylinders(2.9 efi) with gas and his exhaust system was full of it. May not be near your problem but its worth a quick sniff.

 

[mlcasey13]

So I got the truck running pretty good then decided to clean the egr and it was stuck so now it runs even better.

I figured the last step (might should have been the first) was to fill it up with gas and run some seafoam through it. We on my way home from the gas station it started smoking under the hood. So I stopped and took a look and it was burning off the oil soaked up by the woven fiberglass heat shield around the tube running from the header to the egr. I guess the egr hasn't worked in sometime. So my question is can i just take it off and run without it or is there somewhere I can buy a new one?

I found that I can get some stuff from McMaster Carr pretty cheap that is rated to 1400F would that work?

Lastly when I took the gas cap off I heard air either rush into or out of the gas tank and when I was pumping gas I had to go slow or it would spew back out the square hole above the filler hole. Any suggestions on cleaning the vent system on the tank?

 

[brandonzellen]

you can run without the EGR, but you need to block it off, this will trigger a code, but you can bypass that too.. cant remember how, running without it will increse emmisions,(not a big deal) but it will also increase gas milage and horse power. if you do a lil research you can find the proper way to do it. google search how to get more power out of a 2.3, that should find it. just wonderin how exactly did you fix the problem with the idle and stutter? my truck is havin the same problem. 1988 ford ranger. 2.3

 

[4xfanatic]

Ok so update time.

Its decided to hold fuel pressure now dont know what changed maybe operator error with the fuel pressure gauge. It didnt drop but like 20psi over night.

Pulled the coded and it showed a TPS problem and some emissions thing im not worried about. So I checked the TPS and sure enough it wasnt working. After a quick trip to the junkyard (bout 5miles away...lucky me) i didnt find one but got some other goodies including a MAP sensor, but Advance did have one TPS. I threw it on there adjusted the out put voltage to about .9 volts at closed throttle and reset the computer for 30mins.

To bad that didnt fix it and either did the junkyard map. I then checked my timing with the spout removed and it was running right at TC so I adjusted it to 10deg BTDC like the book said. Hooked the spout back up....still doesn't idle right. I did confirm the computer is adjusting the timing cause now it is like 25deg BTDC with the spout connected.

I guess next step is going to be check the egr and make sure it works. Also I may need to replace the hose going to the pcv cause idk if its sealing good.

Im going to try to drive it and maybe burn a little gas through it. Should I run some seafoam or fuel injector cleaner?

How do you reset the computer?

 

[Mark_88]

How do you reset the computer?

Remove the battery ground and leave it off for about half an hour and the computer is reset...

What is it you are trying to do that you need to reset the computer?

 

[4xfanatic]

Remove the battery ground and leave it off for about half an hour and the computer is reset...

What is it you are trying to do that you need to reset the computer?

Im having a similar problem as mlcasey13's. Just didnt know that the computer has to get reset when the tps is calabrated. Is .9 volts correct when closed? I have a 88 2.3 as well.

 

[Mark_88]

Good question...I don't have the specs on the output volts but I'm sure you an find it easy enough.

I meant to ask you if you've changed the MAP sensor recently. My 89 Tempo had one and when it went south the idle was doing similar things to what yours is doing...but it would also sputter at highway speeds some times...

Do not run out and buy a MAP sensor from an auto parts place...they were quite expensive that way...go to a junkyard if you have one around as they are (or were) $5 a piece...but might have migrated slightly higher lately...

 

[4xfanatic]

I havent replaced it. But i did mess with it while trying to fix a different problem. Which i just fixed and now it wont idle. So have to start all over go thru everything again. Ill check that out.