Is there a way to completely take the egr out of line and plug it off to see if its the problem? I dont know if this is feesable or not
I performed the spark test you described on all 4 cylinders and for the most part, the spark is blue. Occasionally though I will get yellow/orange spark. This is true on all 4 cylinders. Could this be what is doing it?
I cannot do a fuel test because there is no test port on the fuel system. I cannot seem to find the fitting that is required for this test. I suspect that if the fuel was at falt that the motor would not rev like it does. It has a great deal of power, but it misses.
Also I have noticed that the voltage going to the coil is over 12 volts. Its more like 13.5 or so volts, I dont know if this means anything or not, but i thought I would mention it anyway.
Well, fuel pressure will need to wait untill i can ubtain the parts to test it, but I am cureous, could i pull the fuel rail and let the injectors spray and tell if they are functioning correctly? Another thought is replacing them one at a time with a new one to see it thats the problem. These are only $32.00 a piece, so I could buy one and try it. or could i pull an injector from something elce and try it? I dont know if they are universal or not.
I was also wondering, what is the purpose of the power transister? If this isnt working properly could that cause the problem?
Im sorry, your probably really getting tired of me and this problem. I really appreciate you trying to help me on this. I will be sure I give you a tip on top of the $15.00 to make this worth your while.
Can I Tee into the fuel system on this? Also, is the return line supposed to be pressurized? I know there is pressure there on the supply side, because the hose stifens up a bit, I didnt think that the return line would be pressurized also.
Please advise on this befor i go any further. Thank you
Ok, I managed to rig up something to connect my fuel guage to and here is what I got.
Key on: Nothing
Start: fluctuates between 38-42lbs
Rev: Pressure increases slightly
regulator without vacuume: 48-50lbs
When I turn the motor off, the pressuer is at about 40 and verry slowly starts to drift off It takes about 20 min to get down to 15lbs.
Its got pressure, what could it be? I thout that the pump was supposed to come on when you turn on the key? Mabe not on this one.
Reason I asked is that I know the timing belt was changed, but I wasn't the one that changed it. It may be possible its not right though. the distributer is ran off the overhead cam on this car.
Here is my threy, If the timing was off one tooth, and the distributer was not moved, this could explane why the timing eas way out before TDC, It wasnt even close to the timing scale. Correct me if im wrong, but I believe that the ignition pulses would be firing too far befor or after the injecton pulses. this may contribute to the black sooty plug and over fueling .
I dont know, its a long shot, but worth a try. I wouldnt think that the moter would have any power if this was the case though
I tread the task of getting into that, but at this point, I think we are running out of options. so far, we have ruled out emissions, ignition, fuel , and such. whats left is beond me. I will look into the timing and get back to you on that tomorrow. In the mean time, is there anything elce that I can check?
ok, I checked the timing and it was ok, however, I took my new plugs out to check them and they were wet. also I pulled the egr back off to clean and reattach and when I pulled the slug of stuff out of the bottom hole on the intake, water ran out.
OK, Mabe we are getting someware, How is water getting into the intake? If its trying to atomize with the fuel, that would most certanly make it miss. I took the throttle body off and the whole intake has a oil film on it, but what about the water? if there was a intake gasket leak, that would not make it go through all the cylinders would it? or the same with a head gasket?
What do you reccommend?
I changed the head gasket and the intake gaskets and no there is no smoak comming from the exaust anymore, also the plugs are no longer wet either. they are burning good and dry. so it appears that two problems got solved with that one.
Now that i have solved the smoaking and wet plugs, I still need to fgure out the miss.
Regardless of the gasket change, it continues to elude me. Any further suggestions?
my vacuum is good, getting about 20 lb
I checked the computer for fault codes even though there wasn't a check engine light on and i got code 15 which refers to the Motor Position Sensor. Im not sure what they are refering to here, there is nothing on the block like a crank sensor or anything. I dont know if this is in the distributer or what. I do know that there is a hall effect in the distributer that has a metal wheel with cutouts on it, is this what they are referring to?
can this be tested? I have called the auto parts store and they cannot seem locate this part. The hayns manual I have doesnt note anything about this sensor either.
How do i test it? I have noticed that when the key is on, but not started, there is a continuous clicking noise from the idal control valve like it cant seem to make up its mind what it wants to do.
ok, the mps ohmed out at 4.21 kohm and the servo range s from .639 - 3.901 Kohm.
the range is smoth, I dont see a problem with this sensor, why would the computer keep this code?
Well, I checked the wiring, everything is tight on all the sensors. I dont get it, it misses at idle and at any other rpm. its almost as if a plug wire is off one of the cylinders, but we are getting spark to all of the plugs on all of the cylinders!
All the injectors are spraying a nice cone shape pattern of fuel and seem to be atomizing verry nicely. I checked this when the intake was off. I hooked the injectors up and cranked the engin and it looks really good. I dont think it is fuel related because I know it would mess with the idle, but the motor runs really good and has plenty of power other than that damn miss.
I fixed the water leak into the intake when I changed the head gasket and intake gasket. all the plugs are burning dry now and look normal. I dont get it at all. ???
Mechanical timing was easy, there is a timing mark on the grank that as lined up with the refrence on the block and there is a timing mark on the cam that was lined up with the refrence on the head. Belt was put on and tensioner was set and locked down. The crank was turned clockwise 2 times timing marks were realigned and double checked and belt was retensioned. Everything god to go.
Ignition timing is set by placing a jumper from the EST Adjust lead to negative ground of the battery, this disables the timing advance. next, making sure everything is off i.e. ac, blower and such, let it warm up to operating temp and place a timing light on number 1 plug wire which is closest to the belt side of the moter. looking down at the damper, with the light, the notch in the damper is alligned to 5 degrees before TDC by rotating the distributer.
Something to note, when timing is being set, everytime the motor misses, the timing mark jumps back and forth wich makes it dificult to set the timing correctly. I have played with this by retarding the timing and advancing the timing, but it doesnt make much difference, it still misses. Currently it is set at 5 degrees before TopDead Center which is what the lable under the hood says to set it at.
like I said, even with the check connector to ground, the timing jumps around when it misses, but ir is more or less at 5 degreed befor TDC
ok, I checked the timing and for some reason, the computer is setting timing about 5 degrees after TDC, that's not right. I checked it again with the check connector and it is 5 degrees befor tdc like it should be.
What is going on here?
This car does not have a crank or cam sensor. I do know that the distributer has a type of hall effect in it, possibly this is what it uses, I don't know. I have looked all over the block for one of these sensors as they are normally either at the damper or the side of the block by the firewall.
yes, this is what i am referring to as the hall effect, that is what i have been told is the name of it. sorry about that.
How do i determin if it is good or not?
So what your implying is that this may be malfunctioning? The disk looks good, however i should mention that the rotor button even though it is fully depressed on the shaft, will move back and forth a little bit, could this be throwing something off? I assumed it was supposed to be this way since the old button was the same way.
The actual distributer is tight an feels good. there is hardly any play in the actual shaft. in the mean time other than this sensor, is there anything elce to check, as i dont own a scope?
Some 1990 & 1991 Excel and 1991 Scoupe models may experience recurrent activation of the "Check Engine" light and setting of fault code 15 in the engine control module (ECM) memory. The vehicle may exhibit stalling at idle and an inoperative air conditioning compressor when this condition occurs.
These symptoms may be related to a poor throttle position (TP) sensor ground circuit in the ECM wiring harness. The field fix procedure for this condition varies according to the wiring harness manufacturer, but basically involves the soldering of a crimp connection.
The connection involved is located where four black ground wires (five in California specification cars) for the throttle position (TP) sensor, idle speed control (ISC) motor position sensor, volume airflow (VAF) sensor, and engine coolant temperature (ECT) sensor (plus the EGR temperature sensor on California spec. vehicles) are joined with two ground wires leading to the ECM. (See splice SCO8 on page 23-3 of the 1990-1992 Excel Electrical Troubleshooting Manual, or splice SCO3 on page 23-3 of the 1991-1992 Scoupe Electrical Troubleshooting Manual.)
wow, that might pose a problem. sounds like a chore, Ill get back to you when i have completed this. in the mean time, let me know if you find anything elce.
Bad grounds are bad things.
well, that was a job getting that out of there, I didnt find anything wrong with the slices, but i soldered them all anyway. I am going to put everything back together now.
Is there anything elce i should look for while im under the dash?
I will have to get one.
ok, so to recap, the plugs are all black and sooty looking, but im getting a good spark on all cylinders. Fuel injectors are all good, have a good spray pattern also. Base timing is set at 5 degrees BTDC but when computer takes over, timing changed to 5 degrees ATDC.
if the crank angle sensor is intermittently shorting, which seems to be a problem with these motors as i have found out by serching the net, that would cause my miss and through my timing out of wack.
Could a coolent temp sensor do this also? I have a thought, possibly due to the advanced timing, the plugs are ignighting too late and causing an excessive amount of unburned fuel to be left in the combustion chamber. this in turn is causing my plugs to turn sooty black and foul. Thus causing the miss. Correct?
I will see about getting a distributer. I called all the local junk yards and all these cars that they have seem to be missing the distributers. ??? Sounds like a comon thing going wrong here. Mabe im just amagining it, or i want that to be it anyway. lol
yes, looks like i can get one for $50.00
I dont know that the lead time will be on the shipping though. Will this forum stay active untill it gets here?
just cureous, what is the power transister for on this motor?
I got the distributer and installed it as well as a power transister, no change though. The timing seems to have streightened itself out though, it isnt jumping around when I set the base timing anymore. But something elce isnt right.
I have also noticed that the idle control valve just sits there and makes half revolutions back and forth, but doesnt really do anything. This is true when you turn the key on and when the engine is running.
This dont make any sence, what would be next?
it doesnt work that way, this is an assymbly that has the idel control moter and motor position sensor connected behind the throttle body. the plunger pushes on the throttle to open it.
I have tried unplugging this, no change. the motor just rotates back and forth without actually moving the plunger. I have tested this assymbly per instructions and I do know that it works. If i put a 6volt battery on the motor, it will fully extend the plunger and retract it, but the computer just pulses it back and forth.
the motor control sensor was tested also and it was also good. as the plunger moves back and forth, the resistence changes smothly as it should.
I dont understand why it bounces back and forth like it does, but this is regardless of wether the motor is running or not.
well, i done the test you mentioned, and all the cylinders changed the rpm of the engine.
You could definately hear that there was a plug off.
Another thing, I put brand new plugs in and within 5 minutes, took them out and they are all saturated and black. Its like its getting too much fuel or something.
also, what would make the idle motor act up like it does?
would it be possible that the ecm is going bad?
motor mounts are good, I also tried running a ground to the body from the motor, but no change. I also cleaned all the cables from the body and battery. no change.
I fixed the car, I got a ECM from the junk yard and the missing went away and the IACV is now working like it should. I took the brain apart and there are several capaciters that are charred.
I am cureous if the guy that had this mabe put the bad distributer cap on and when it started acting up, mabe started prodding around on certain sensors and trickeled some stray voltage into the computer and fried it.
Oh well, its fixed now anyway.
I want to thank you for all the help that you gave me, I appreciate it verry much.
ok, I have a new problem, and cant seem to figuer this out. Car has been running fine for some time now, but recently It has been trying to flood when attempting to start it in the mornings or when it has been sitting and cools down.
Something is causing it to dump excessive fuel. also it wants to drop the idle down to 500 rpm or so. I have to keep it revved up untill it warms up in order to keep it started. The exaust smells strong like gas also.
I changed the coolent temp sensor, O2 sensor, checked fuel regulator, etc and cant seem to figure out the problem.
When it warms up, it runs fine, except for a little ritch mabe. Pulling the plus after running it, look to be whitish soty looking. replaced plugs.
Any idea what is going on here?