Its an 88 with a 5.0
So it's been riding like . In idle it misfire and burn richly. Un burned gas (black/grey smoke out exhaust non stop) When you give it gas while in park, it'll still function but misfire causing entire car to shake. THen once you let off the gas it dies. I've had a few mechanics look at it and nobody can figure it out. This is what i've done to try to troubleshoot the thing:
-New spark plugs
-New Spark plug wires
-New distributor cap/rotor
-New MAP/BAP sensor
-New MAF sensor
-New ignition coil
-New o2 sensors
-New EGR spacer
-New fuel pressure regulator
-New "idler"
-New TPS (adjusted to 98)
-New gaskets on Upper to lower intake manifold
-I've checked all vacuum lines and made sure they're connected properly and going to the right place
-We've double checked firing order
-Checked manifold with vacuum gauge
-Unbolted exhaust to check for any clogs
We CAN NOT run codes because car will not last long enough for us to pull the codes. Before it was dying it was throwing a TPS code so we replaced it. Still nothing. Check engine light came on a few days after this starting happening.
Please help. I'll pay anything to get this issue fixed.
If you have any suggestion post here or PM me.
You don't have a vacuum to the MAP sensor do you? What is the timing set at? How did you set the timing? Are the spark plugs wet with gasoline? Maybe the FPR is no good.
Hey vinnie! No vacuum up to MAP. Its got a small plug on it to cover it. Timing is something i have to re adjust today. Spark plugs do get wet with gas after each start. Fuel pressure regulator got replaced with a new one.
Is everything stock?
When you turn the key on does the fuel pump run for two seconds and shut off?
This proves the program in the computer is running.
Check that the fuel pressure holds after you shut the engine off.
This will check if your injectors are sealing and not dumping in extra gas.
You can pull codes without the engine running.
It's called KOEO (Key On Engine Off) mode.
It will run tests and report codes and also read out codes in the computer memory.
You can pull stored codes from the memory, irregardless of engine running or not.
Always pull codes...always.
Do that, then get back to us with your findings.
EDIT: softtouch beat me lol.
Also, as Vinnie suggested, make sure your timing is set correctly. Pull the SPOUT connector before setting or resetting the timing. If the timing is off, throwing 250 dollars worth in new parts won't fix .
Timing.
Codes.
That will narrow it down by 75%.
If it's a BAP it has to be open to the atmosphere not plugged.
Exactly. It's probably not a cap, but a plastic part with a hole in it to prevent one from putting a vacuum tube on it.
Its not a cap, but its correct. Its a small cover type thing so a vacuum doesn't go on it. Its a brand new one. I'll go pull some codes RIGHT now :)
KEOE codes pulled
18- Loss of ignition
63- TPS
and 31 EGR valve position or exhaust
Brand new EGR and brand new TPS and also brand new ignition coil. I dont get it : /
throttle position sensors have to be calibrated, i think...
The TPS was set to .98. Suggested =.96 (correct me if im wrong)
I had a fox mustang/tbird mechanic over here to help. He's a good friend of mine with 3 88 saleen mustang coupes (beautiful fkkn cars)
He knows his stuff, and we can't figure it out.
PLEASE feel free to brainstorm outloud. I'm willing to try anything. I've probably spent 20+ hours researching and 50 hours outside by the car : /
This is literally taking up all my time and i'm getting sick of it.
Is the Mass Air meter electronics or the car's computer bad?
Are the plug wires on in the right order? How are the fuel injectors/ Does the MAF match the injectors? What computer do you have in the car?
It could be injectors, try pulling a spark plug wire off one at a time,maybe you can isolate to a cylinder or two. I had to change my injectors recently for a similar problem, but not as bad. That code 18 would have me wondering.
Are you running the right injectors? What computer do you have and what Mass Air meter do you have? I have an A9P computer in my car and it's programmed for 19# injectors. I installed an aftermarket MAF so I could run 24's.
Lets start from the beginning
Did you check the compression???
Did you check the Fuel Pressure
Do you have GOOD SPARK. Blue in COLOR. At the PLUGS??
Please post back and i may be able to help
Note TPS settings can be anywhere from .65-.99. Its not that critical of an adjustment as people think.
Tthat car has a BARO SENSOR NOT A MAP. Their fore no vacuum hose should be hooked up to it..
http://i740.photobucket.com/albums/xx46/proguns/001-43.jpg
BARO ON THE LEFT
The MAP and BAP are the same thing...are they not? One has the vacuum connected, the other doesn't. All I did to my car when I went Mass Air to convert was to remove the vacuum hose from it. On factory equipped Mass Air cars, there's a small plastic "cap" with a hole through it placed on it from the factory to prevent one from putting a hose on it.
BAP/Map are dif just because some are speed density others are MAF. MAF equipped cars have no vacuum going to the sensor. The spark in the car is fine, distributor is supply spark to all 8 cylinders...trust me i got shocked 8 different times.
Fuel pressure is right on the dot, we tested it after we checked all fuel injectors, fuel rail, and changed the fuel pressure regulator.
The computer was replaced a few months ago to match up with the MAF. The computer was quite pricey and bought from summit. I know it's the correct match up for my BBK intake and current MAF sensor.
When i pull off a spark plug wire it makes no difference whatsoever... no matter WHAT plug it is. I can pull the wire off of #1 while its running and you can't hear or see a difference. i can pull off #5 and the same thing. Im beginning to think something MAJOR is wrong on the inside of this engine. It seems like i've checked and double checked anything i think that can be wrong that is a minor fix. I've had 5 ASE certified mechanics officially give up... AAA came by 2 days ago, and they had no idea... the local for dealership (any for dealership usually sucks anyways) looked at it and was speechless... they had no idea how to work on anything that requires knowledge,...
And yes vinnie, the wires are in the right order. :)
Vinnie when you converted you disconnected the hose from your map and it worked because a map reads exactly the same as a BARO sensor with the hose from a vacuum source is removed. But their is a difference in sensors they carry 2 different part numbers. But Yes when both of them are opened to the atmosphere they read IDENTICAL. Thanks
Once again what is the COMPRESSION
DRY AND THEN WET???
When disconnecting plug wires its strange that the engine does not respond to that. Clearly something is wrong and i think it might be mechanical and internal. But without having hands on its difficult to diagnose a trouble like this. Can you post some video with sound. You may have a busted valve spring rocker push rod ETC. Good luck Tom
It kinda sounds like how my daughter's Mustang ran when a loose timing chain jumped over a couple of teeth.
Has it ever ran right since you upgraded it?
I saw the two different part numbers, but isn't the "E6" and E7" prefixes the model year of the part?
I would listen to Tom, he has been right and corrected me more times in the last week than I have suffered in most of my life. He knows his shiznit.
When I first saw the symptoms, I thought your EGR valve might be stuck. Then when I saw EGR in your list of codes, I really thought it might be stuck :)
Pull that EGR valve and see if it moves freely. If it gets stuck open, your car will idle like (if at all).
Tell us a little on the backstory of the engine itself.
Is it a converted SO? Different cam? What about the timing itself? Were the marks on the cam and crank aligned? How about the distributor? Since you have fuel and spark, it sounds like something is out of time. My buddy had a '90 Stang that was stock except for a Cobra intake...it ran just as yours is...turned out the timing chain slipped or somehow it got itself way off time. It wouldn't idle, smelled of raw gas, ran like shiznit, and sounded like it too. He yanked it, pulled the front cover off, it was off by several teeth.
Not exactly sure this your problem..and it probably isn't, but might be worth a thought if nothing else pans out...
Just sayin'...someone else may have worked on it and not got something right.
Edit..EGR doesn't affect idle.. ;)
Not sure about compression, but the EGR is fine. It's been replaced 3 times now with NEW ones and used ones that have been tested.
Also, that was one of my next assumptions is if the chain skipped a couple of teeth... would i just had to take out distributor and re adjust that?
Yeah the more and more i try the things on my list of ideas and nothing works, i lean more towards the timing chain skipping a few teeth. The engine has always been fine. It came out of a 1993 cobra, and has never had issues. oil changed every 3,000 miles. It goes to a mechanic every 5 months or so. It's hooked up to live diagnostics at our shop every 2 months for shiznits n giggles.
We have spent plenty of time working on this thing... I'll post a video up of the sound when i get a chance
If the chain jumped the compression will be low. Readjusting the static timing wont fix that. I have seen the cam pin shear in some engines. Do a compression test it might shine some light on the Subject Thanks
Right..if the timing chain has slipped, it's either loose, or otherwise needs replaced. Short of a compression test as Tom suggests, the only other way to see would be to pull the front cover and get a visual. It may be time for a replacement chain anyway..
Yes Vinnie i was just showing the difference in the connections. The difference in the sensors is minimal but they are slightly different. One converts Vacuum into a resistive value and the other reads Barometric pressure. Both sensors produce the same resistance when they are at atmospheric pressure. So either one can be used as a BARO SENSOR OR MAP SENSOR. I actually did a comparison on both and their performance is similar. But they do carry a different part Number. I would venture to say they are slightly calibrated for different applications. Example my MUSTANG has 2 part numbers for the TPS sensor. One is tuned for a different emission parameter. But the auto part store only lists one TPS for my car. The sensors are slightly different but close enough i guess by application Thanks
You can also remove the valve cover and see the timing events. Or rock the damper bolt back and forth to see the chain stretch. But a compression test will expose a jumped chain faster than a 3 LEGGED CAT RUNNING OUT OF A DOG POUND.
^ :bowdown::rollin:
Ok so being the stupid person i am.. i can not find my compression test kit at home. I will run down to the shop tomorrow and post the compression test readings and will run codes again.
Thanks a ton everyone.
Thanks Tom. I appreciate that info. When you're down in Southern Oklahoma, I'll buy you supper.