I've searched the forum for some time to try to get an answer to my situation and have found some information but it still doesn't add up.

I have a 1995 California Truck with 5.8L, 132K miles.
In the morning when I start the truck it runs at the typical cold idle speed of 1100 RPM. Then, within 2 seconds the check engine light flashes four times and the RPMs increase to about 1600 and stay there for a good 10 seconds before settling down to 1100.

I have read on here, possible vacuum leak, frayed negative wire on the code readers which cause the diagnostic to start, and a bunch of sensors like TPS, ignition stuff.

The weird thing is this only happens when the truck sits overnight. It will sit in the parking lot all day at work and at the end of my day will startup and run just fine. Runs fine when warm too. Any thoughs (this just started happening this week.)

I though it was a misfire at first becuase the truck would start hard in the morning (take a few extra cranks to fire and sputter), but I cycled the ingitiion a few times to get the fuel pumps to prime and it started much faster this morning. Still had the first problem above though. Not worred about this as much but is there a valve that is failing allowing loss of fuel pressure?



Changed plugs and wires a month or so ago.

 

Step one - have you pulled the codes?

 

I have almost the same problem with mine. I have a 95 5.8. California truck, and it started happening a year ago at 124,000 miles.

No hard starting, but it will usually go through the RPM climb exactly as you describe, CEL flashing, hold at about 1500 rpm for about 10 secs, them stumble down to a normal idle. No codes are stored, engine off or running.

I have checked or replaced : MAF sensor, O2 sensors, TPS, ECT, IACV, battery, DPFE, EGR, vacuum lines. I probably forgot some stuff I did.

I am probably going to replace the computer.

It's really a bummer, as the truck runs great besides this. I like all my stuff to run perfectly, and this situation really takes a lot of the fun out of owning this truck.

 

I did not pull codes, but will this weekend. From what I've read this will not throw a code but I'm sure you will say it doesn't hurt to look. I will post/search for any codes I find. I don't really care if it keeps doing it as long as I can reasonably rule out that it is causing major harm.

 

If the CEL is coming on(flashing) and then going out, codes should be stored. If you're not getting stored codes, I would think you have a computer or wiring to computer problem. Maybe a short?

 

my 95 with 5.0 did this for 6 months,then started dying at will and not starting for a couple hours. No codes while it did the idle up,CEL flashing. I did not get a code until it started dying and leaving me stranded. I ran codes after it started dying,and got PIP sensor bad(pick up coil in distributor). i took the easy way out and replaced the distributor. No more high idle and CEL flashing,and truck runs better than it ever has now. Not saying this is your problem,just another thing to consider.

 

I am going to work on it tomorrow. I will try to pull the codes using the no code reader technique (counting flashes of CEL). If that doesn't work, my co-worker has a code reader.

Thanks cj. Did you use a Motorcraft distributor or aftermarket? The motorcraft is $300+. To be honest though, I would rather have it throw the code, spend some coin and be done with it rather than chasing a ghost. We will see...

 

i got my distributor from one of the sponsors on here,fte parts guy i believe it was,and yes it was a motorcraft. $292 if I remember correctly.

 

Okay, Pulled the codes. The only thing I got was system pass (111). I mentioned earlier that even though it sits all day at work, it does not have the high idle problem. It is still in the high 70's, dry and sunny when I leave work. SO... on Saturday, I waited till the middle of the day to start it. Sure enough, it started fine with no high idle and no flashing CEL.

Not sure what this means... I am running some injector cleaner through it to be sure it isn't a clogged injector. I still have a half a tank to go. We will see if it gets any better. Bought the truck from the original owner and he didn't drive it too much the last year or two as he has a new ford F350 dually.

 

and thank you for your business!


Ed

 

Did you just do the KOEO test and stop after you got the 111. If so you need to continue on and after the first 111 (this only tests the sensors for voltage levels).
After the first 111 you need to wait a little while and then it will read out the CM codes. If you do not get any CM codes then you need to run the KOER test.
If you get 111 with the KOER test being a California truck you need to run the engine balance test then and a code 90 is the passing code. If you do not get the code 90 you need to run the engine balance test tow three more times depending on the severity of the engine problem.

I think your PCM computer is OK.

 

Okay, Thanks for the info Subford. I did wait a little while after the KOEO. I got the 111 code and then it repeated a second time. After that, nothing. Do I simply start the truck after that to run the KOER sequence or do I need to turn off the ignition and then start? Or is the process completely different?

While I am getting a little ahead of myself, how do you run the engine balance test?

 

Engine Running Self-Test
Special Notes:

On vehicles equipped with the Brake On/Off (BOO) circuit, the brake pedal MUST be depressed and released AFTER the ID code.

On vehicles equipped with the Power Steering Pressure (PSP) switch or sensor, within 1 to 2 seconds after the ID code, the steering wheel must be turned at least one-half turn and released.

On vehicles equipped with electronic overdrive transmission, the Transmission Control Switch (TCS) must be cycled after the ID code.

The Dynamic Response code is a single pulse (or a 10 code on the Super Star II Tester) that occurs 6-20 seconds after the engine running identification code. (See Code Output Format in this section.)

When/if the Dynamic Response code occurs, perform a brief wide open throttle.

How To Run Engine Running Self-Test


DO

Deactivate Self-Test.
Start and run engine until it reaches normal operating temperature.
Turn engine off, wait 10 seconds.
Activate Self-Test.
Start engine.
After the ID code, depress and release the brake pedal if appropriate. See Special Note on previous page.
After the ID code, within 1 to 2 seconds, turn the steering wheel at least one-half
turn and then release it, if appropriate. See Special Notes above.
If a Dynamic Response Code occurs, perform a brief wide-open throttle (WOT).
Record all Diagnostic Trouble Codes (DTCs) displayed.

DON'T
Depress the throttle unless a Dynamic Response code is displayed.
Cylinder Balance DTM - SFI Engines Only

The purpose of the cylinder balance test is to assist the technician in finding a weak or non-contributing cylinder. The test is entered by depressing and releasing the throttle within two minutes after the Engine Running Self-Test DTCs have been output.

Once the test is entered, the IAC duty cycle is fixed and the engine is allowed to stabilize. Engine rpm is measured and stored for later use. Next, the fuel is shut off to one of the cylinders depending on the engine. After a brief stabilization period the engine rpm is again measured and stored. The injector is turned on again and the process is repeated for each of the injectors down to one. At this point, the maximum rpm drop that occurred is selected from the table of rpm drops for each cylinder. This maximum rpm drop is multiplied by a calibratable percentage. The resulting number (rpm) is used as the minimum rpm that each cylinder must have dropped to pass this test.

Example: 150 rpm x 65% = 98 rpm

If all cylinders drop at least this amount, then a code 90 is output indicating a pass. No further testing is necessary. If a cylinder did not drop at least this amount, then the cylinder number would be output. For example, 30 for cylinder number 3. This indicates that cylinder number 3 is either weak or non-contributing.

The test can be repeated a second time if the throttle is depressed and released within two minutes of the last code output. This time the maximum rpm drop that occurs is multiplied by a lower percentage. This number is used as the minimum rpm drop for each cylinder to pass this test.

Example: 150 rpm x 43% = 65 rpm

If all the rpm drops are greater than 65 rpm, then a code 90 is output. If cylinder number 3 had failed the first level and passed the second, then cylinder number 3 is considered to be weak. If cylinder number 3 failed again, the code 30 would be output again.

The test can be repeated a third time by depressing and releasing the throttle within two minutes of the last code output. This time the maximum rpm drop that results is multiplied by a still lower percentage. This number is used as the minimum rpm drop for each cylinder to pass this test.


Example: 150 rpm x 20% = 30 rpm

If all the rpm drops are greater than 30 rpm then a code 90 is output. If cylinder number 3 had failed the first and second level, but passed the third, then it is considered to be a very weak cylinder. If cylinder number 3 failed the third level, then a code 30 would again be output. In this case, cylinder number three would be considered a non-contributing cylinder.

The Cylinder Balance DTM may still be repeated as many times as desired by depressing and releasing the throttle within two minutes of the last code output. All further testing (i.e. 4th, 5th pass) will be done using the third level percentage.

 

Seems pretty straight forward but I have a few questions. Thanks for being so patient with us Newbies!

Do I have to do the test multiple times to accomplish all of the above or do I press the brake at the same time I turn the steering wheel. 1-2 seconds does not give you a lot of time. I do have the overdrive transmission as well. I'm assuming you do these things in succession

Also how do I know if I have BOO and PSP circuit?

 

No, you do not have to run the KOER test multiple times. You push on the brake and push the OD button right after the ID code is flashed.
A computer can not see you do them at the same time. It only sees one thing at a time. So just do them one right after the other.

You do have the BOO circuit.
I think you said that you had a 5.8 L engine so you do not have a PSP switch. I do not know if any 1995 F-series had the PSP switch but the 5.0L had them in the late 80's and early 90's.

The engine ID code would be 4 for your engine.

Here is a URL to click on for a list of codes. You only have three digit codes.

http://www.broncodata.com/tech/codes.htm
/