Check engine light on

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SYCLONE123

Banned
so everythin was fine then out of nowhere i start my truck (already warmed up) my truck starts idleling at 1800 rpm for a minute then goes back to 700rpm and my check engine light turns on everytime it does this and stays on. checked timing set at 0 degrees unpluged wire by computer before changing timing. now my fuel pressure thats a diffrent story i do not have a gauge so i dont know what pressure im runnning, would my fuel pressure cause my check engine light to come on? i do not drive my truck i just pull it in and out of my shop everymorning and it just recently started the check engine and high idle issue, also if i give my truck 1/4 throttle it pulls pretty hard not even boosting but at full throttle it pops or backfires:tdown:
 
0966Sy

0966Sy

Code what?
Re: Check engine light on

Lets start with what code(s) is present, using a paper clip to read the codes is simple. Look it up or use the search feature
 
SY-1193

SY-1193

Active member
Re: Check engine light on

SYCLONE123 said:
so everythin was fine then out of nowhere i start my truck (already warmed up) my truck starts idleling at 1800 rpm for a minute then goes back to 700rpm and my check engine light turns on everytime it does this and stays on. checked timing set at 0 degrees unpluged wire by computer before changing timing. now my fuel pressure thats a diffrent story i do not have a gauge so i dont know what pressure im runnning, would my fuel pressure cause my check engine light to come on? i do not drive my truck i just pull it in and out of my shop everymorning and it just recently started the check engine and high idle issue, also if i give my truck 1/4 throttle it pulls pretty hard not even boosting but at full throttle it pops or backfires:tdown:
Click to expand...

I read what you posted here. I am going to question part of what you wrote... It may just be the way you wrote it or worded it but I will ask anyway.

You wrote: "...checked timing set at 0 degrees unpluged wire by computer before changing timing."
The reason this stood out to me the way it is worded to me sounds like the timing is off.
Did you unplug the Tan/Black jumper and set the timing with a timing light/plug wire #1 to 0 timing with the wire unplugged?

Again it may just be the way you worded it but at idle your timing should read approx. 23 degrees or so with the wire plugged in. 0 degrees wire unplugged.
 
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SYCLONE123

Banned
Re: Check engine light on

ok im confused i thought you unplug the wire set timing to 0 and plug it back in and youre set... i do not have an advance timing gun... so i should set timming at 23 degrees?
 
SY-1193

SY-1193

Active member
Re: Check engine light on

SYCLONE123 said:
ok im confused i thought you unplug the wire set timing to 0 and plug it back in and youre set...
Click to expand...

Yes,
0 degrees with wire unplugged.
approx. 23 with wire plugged in at idle.

I was just the way you worded it. The symptoms you discribed also could have been from the timing being advanced too much. The truck would go like hell because of the timing advance and then pop at higher rpms.
 
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SYCLONE123

Banned
Re: Check engine light on

ya after i set timing to 0 i tested it out and it ran the same its pops when i fully boost up to 15lbs when i hear it i let off
 
0966Sy

0966Sy

Code what?
Re: Check engine light on

The check engine light I guess could only mean one thing, open the hood and check to make sure the engine is still there. I guess sence you checked the timing that means the engine is still there, so whats the problem?
 
IpHoOnDyou

IpHoOnDyou

New member
Re: Check engine light on

SYCLONE123 said:
ya after i set timing to 0 i tested it out and it ran the same its pops when i fully boost up to 15lbs when i hear it i let off
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Well you defnetly have a timing/lean/tune issue, i would pull the code or codes an go from there. If you say its "poping" that is a sy or ty's worst enemy! With a boosted vehicle an your getting knock i would not cross into boost any more before you figure out what is going on. I would also invest in datapro an a ALDL cable to see exactly what you truck is thinking. I bought the aldl cable hooked my laptop up an ohhhhh boy did i find things i didnt like but it helped me trace down issues like this an fix those issues. Last year with just decribed ubove i ran my Ty which is all stock becides a walbro an a RPM fuel reg an datapro an got that brick down to 13.1 in the 1/4. Im not trying to highjack a thread just lettin you in on a little info that will only benefit you in diag but also tuning also
HTH
Steve
 
S

SYCLONE123

Banned
Re: Check engine light on

0966Sy said:
The check engine light I guess could only mean one thing, open the hood and check to make sure the engine is still there. I guess sence you checked the timing that means the engine is still there, so whats the problem?
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funny guy,, but anyways im going to pull the codes and see what pops up thanks
 
S

SYCLONE123

Banned
Re: Check engine light on

check the codes with ign on engine off it just pulls code 12 over and over again after the tenth time i shut off igniton and turned the truvk on and it went haywire fashed like 5 times super fast and paused and flashed so fast i couldnt count it but it looked like more then 7 which doesnt make sense and if i leave the clip in and turn it on it runs like crap and as soon as i take the clip out the idle goes up and stop sputtering
 
S

SYCLONE123

Banned
Re: Check engine light on

and i also notice my check gauge flickers on and off and i traced it down to my steering wheels turnsignal electrocics if i move the wheel i can hear the turn signal solenoids going off im guessing they both started right around the same time
 
The Bronze

The Bronze

New member
Re: Check engine light on

A serious question: The check engine light is illuminated, and then you are pulling the codes right? In other words, you are looking for codes when one should be present, and not after you pulled the ECM fuse or such?
 
0966Sy

0966Sy

Code what?
Re: Check engine light on

A code 12 should flash a few times to let you know it's comunicating and any additional codes will follow. Flash flash pause flash flash flash would be a code 23 for example. If you pulled the ecm fuses you probably have already cleared the code from the ECM and will need it to set again from the fault to be pulled.

From the symptoms you first mentioned i would look into your IAC valve/circuit. Getting a code first will help you start in the right direction rather than guessing. So try and wait for the checkk engine light to come back on and try again to read codes. Dont start the truck while reading codes
 
The Bronze

The Bronze

New member
Re: Check engine light on

SYCLONE123 said:
i do not drive my truck i just pull it in and out of my shop everymorning .....if i give my truck 1/4 throttle it pulls pretty hard not even boosting but at full throttle it pops or backfires:tdown:
Click to expand...

Off topic, but when you get this fixed, you might want to lay off pulling it into the garage at full throttle....;)
 
SY2455

SY2455

70's Veteran
Re: Check engine light on

OK, Here you go if it will help you. With a paper clip connect ALDL terminals "A and B" Turn the KEY ON, ENGINE NOT RUNNING. When you get the codes from the check engine light. It will show the codes like this.

1. A code 12 will flash 3 times to show the system is operating normal. This will be shown as a flashing light.
Each - will = 10's, Each . will = 1's. The - is a longer duration of the check engine light on, the . is just a flash. The check engine light will show a code 12 as this.
-.. -.. -..

2. After the check engine light shows the code 12, there will be a short pause before the real important stuff. The check engine light will then begin flashing EACH trouble code 3 times before moving on to the next touble code that is store in the ECM.

3. It should look something like this.

-.. -.. -.. pause --.--.--. pause --..--..--.. pause ---...---...---... pause ---....---....---.... These would be the following. Codes 12,21,22,33,34. At the end of all the problem codes, the check engine light will again flash a code 12.


There are about 19 codes that could set the check engine light and 1 that does not. The next time it does it write the codes down and we can go from there :tup:.
 
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