brief check engine lite ?

[95ss]

My wife reported the check engine lite came on .......then went off? I checked the oil and coolant....oil shows half qt low....coolant is visible but could take 6-8 oz. Nothing else is obvious .....anyone have any tips.? will a scanner work on this car? I have a auto x ray code scanner .
Thanks....

94 SHO, 3.2 AUTO .....is that the only way they built them in 94?

 

[SHOdded]

How many miles on your SHO? Is it normal for it to consume oil/be low on coolant? Any visible leaks (like rear cam seal/valve covers, water pump, etc) or smells?

You can get the codes with a paperclip and counting off the flashes. The 94 is an OBD I vehicle, from the website I see the 6000 and 7000 models can scan it. If the oil light is flickering that means time for rod bearings. If the battery light is flickering, could be battery or alternator.

93-95 saw both MTX and ATX SHO's being built.

 

[95ss]

Thanks....I figured out the key off test and got a 539 and a 214 ....key on and engine running 521 and 632.....feel free to post what the codes mean....I am going to GTS it "google that shit"
Rick

 

[SHOdded]

Did you go to the link I provided for the codes? That site makes it real easy! Since yours is a 94, you have 3 digit codes. Looks like the only "legit" code for now is the 214. Cam sensor (CPS)/DIS and/or wiring to either.
So I would check the grounds first. They may look fine, but sometimes cleaning and reinstalling works wonders, especially the ground strap from the rear passenger side of the intake to the firewall.
Check the CPS area for any oil leaks, the usual culprit for erratic behavior/failure. Cleaning sometimes will work, but usually replacement is the fix, along with a GOOD seal like National brand, not FelPro. CPS replacement and How to check CPS wiring
Take the DIS off, clean off the back side/intake mounting area, put a bit of heatsink paste or dielectric grease and reinstall.

 

[95ss]

Hi, yes I did check the link for the codes and I went and reseated the plug and insured the area is oil free. I am going to redo the grounds. I had a hard failure today ...I will describe how it happened, I have pulled a 212 and a 214 code with the test key on and key on and running. (got some other codes but they are not valid....just didn't do the test right.) soooo 'Loss of ignition diagnostic monitor input to pcm/spout circuit grounded' and cid circuit failure. ;;;;; of note to me.THE TACH QUIT ...I started the car and it didn't start right away.....did a couple of misfires and then started up alittle rough. Then about 100 yards down the road the engine lite came on and 60 seconds later it ran rough and at idle for a stop sign it died. restart...failed 4-5 times then a few times it fired but failed to complete the full cycle ...sort of a stumble and fire then almost stopped like the timing was out of wack , if you ever had the old school exp of a hot start of a high compression engine ....it was like that in the sense that the engine almost stopped turning over while the starter was fully engaged.

I DID SEE THE TACH START UP JUST AS I PARKED THE CAR AT HOME.... the check engine light went out at the same time.
it also failed during the test.....but started up again.
so...ignition diagnostic monitor input? can you guys give me any thoughts on this? where does idm get its signal from? or is the idm a stand alone component? The cps is for sure a possibility because it was subjected to a huge leak for a long time judging by the amount of oil I removed from the area. I did repair it and it does not leak now...but damage may have been done already. I am hesitant to just replace it without some justification....I have lots of experience of replacing expensive electronics, and discovering I 'guessed wrong' .....aircraft avionics are not cheap.....and my boss is a hard man.
so If you guys could explain some of the signal paths that would help. a lot.
Thanks.
Rick

 

[SHOdded]

definitely sounds like cam position sensor replacement time, based on the numerous occurrences & resolutions recorded on this forum alone. As to the electrical specifics, I am sure a guru will chiime in and clarify. But you would do yourself a favor to pick up an EVTM manual from EBay or someone on this forum selling one.

Sometimes the hard start is due to leaking injectors and a hot start combo. But since the tach obviously was uncooperative, the CPS is the #1 suspect.

 

[95ss]

Thanks....does the cps provide the signal for the tach? via the ecm? I will see if I can find any electrical diagrams....I have a pdf for the 89 sho with diagrams...would that work? I am working on the ground strap now.

Thanks a lot for the info.
R

 

[95ss]

what brand of cps should i avoid?

 

[luigisho]

Most of them are ok. the only time I had what I would consider earlier than normal failure is when there is a good sized oil leak at the seal behind the sensor. When in doubt I usually go motorcraft or acdelco if available.

If you are going to replace the sensor check for oil leak at the camshaft seal. Also clear the codes and see what if anything shows back up. You could have a bad DIS or a short in the SPOUT wiring. The SPOUT plug makes identifying the wire(s) easy

 

[rubydist]

read the codes again. they blink out the current codes first (from lowest number to highest number) and are repeated twice. then there is a single pulse separator and then it blinks out the stored codes (again from lowest to highest) and again repeated twice. the way you reported the codes and the numbers you got tells me you did not count them correctly (which is easy to have happen...)

 

[95ss]

with the key on engine off i had
if i remember correctly I had a quick dim 3 pulses then flashing light as follows
1 then 539 pause 539 pause 1 then 212 pause 214 pause 212 pause 214 and then i lost count.....
so i did it again
I had a quick dim 3 pulses then flashing light as follows
1 then 539 pause 539 pause 1 then 212 pause 214 pause 212 pause 214 pause 1 then 137 pause 137 end of lights

so i tried to do it with the engine running and really messed it up because i did not turn the wheel and hit the gas at the right time.
but here are the numbers I did get the 3 flash's for the 6 cyl eng code.
quick dim flash then 1 632 632 1 539 539 521 632 538 536 521 632.....my order went to **** here cause i ran out of paper....but regardless of the order it was clear that they are related to steps i did not do correctly.

I repeated the test and 1 539 539 1 212 214 kept on showing up. the tach failed during the test and the light stayed on, later the tach worked and the light went out. so if the cps is responsible for this signal i figure it may be the culprit.
sound reasonable?
I cleared the codes i think....by removing the jumper when the koeo test finished. started the engine up and it ran ok...no light and normal start w engine idle.

I did do the test yesterday after the first failure, I do not have the paper infont of me but i know the 539 and 214 were displayed. the 212 is new.
Thanks for all the help.....I really appreciate it!
Rick.

 

[rubydist]

like I said, they display from lowest to highest in each section, so if you think you read "539, 539, 521, 632..." you have it wrong. it does not repeat until it goes through the entire section from lowest to highest, so in that example it would not display "539, 539..." it would rather display "512, 539, 632..."

perhaps you can shoot a video of the light blinking so we can interpret it for you.

if you really have a 214, as is indicated by your tach symptoms, I would replace the cam sensor. a sick cam sensor can cause all sorts of bad things including running rough and/or stalling.

 

[95ss]

ok....I will try again, thanks again
Rick

 

[95ss]

Replaced the cps ....drove it around town and got a few check engine lites....but the y were brief and went away. ran a quick scan....I am still trying to decide if i am doing it right or wrong.....I video'd it so i can decode it correctly. More after i work on the broken cam chain tension screw on my cb-400f honda.