this car really sucks
- Thread starter hi_po_heads
- Start date
-
Sponsors (?)
common guys....
1. Is it throwing any codes? Also, make sure the light bulb for the Check engine indicator is not burned out or removed....should light up when you turn the key to "on".
2. Does it have EGR. Is it possible the EGR is stuck open?
3. Are the injectors matched to the MAF? Are you sure?
4. What color is the exhaust? What do the spark plugs look like? Gap?
5. Bad PIP sensor?
6. The ACT sensor has a direct affect on air fuel ratios. Also the Barometric Air pressure sensor.
7. Spark plug wires! The older the wire, the higher the resistance it will develop. This will render your coil useless (eventually).
8. What is your compression? Pull off the oil fill cap and stick your face over the fill neck. Do you feel a breeze pulsating with the engine. If yes, you got blow-by and probably crappy compression. What is the mileage on the motor?
Get us some more info. We can figure this out.
P.
1. Is it throwing any codes? Also, make sure the light bulb for the Check engine indicator is not burned out or removed....should light up when you turn the key to "on".
2. Does it have EGR. Is it possible the EGR is stuck open?
3. Are the injectors matched to the MAF? Are you sure?
4. What color is the exhaust? What do the spark plugs look like? Gap?
5. Bad PIP sensor?
6. The ACT sensor has a direct affect on air fuel ratios. Also the Barometric Air pressure sensor.
7. Spark plug wires! The older the wire, the higher the resistance it will develop. This will render your coil useless (eventually).
8. What is your compression? Pull off the oil fill cap and stick your face over the fill neck. Do you feel a breeze pulsating with the engine. If yes, you got blow-by and probably crappy compression. What is the mileage on the motor?
Get us some more info. We can figure this out.
P.
i changed out for a new fpr tonight, i know this one is good but it made no difference. ive had it put on a computer and it pulled a tps code. we changed that, the check engine is still off. i am running a completely stock motor. my egr valve has been bypassed, i put the stock mass air meter with 19# inj back in, my plugs are flooding. what is a pIp and act sensor? i just changed wires 2 times, compressin is good in all cylinders, i have no cats on the car, this motor has only a few miles on it. Honestly the only thing i can think of that hasnt been changed is the fuel pump. but i didnt think that the fuel pump would hold good pressure if it was bad. this pump will push at least 60 # according to my gauge. but thanks for the help. im still trying
what is the FP set at now?
I doubt it's fuel starvation. Are you hearing any detonation (pinging). If not then it's not likely to be fuel starvation.
What numbers did you get on compression?
Are your headers glowing or getting very hot? what is your operating temp at after 20 minutes of idling?
How are you measuring your RPM's? Stock gauge or aftermarket? Is is possible it's actually reaching 6250 rpm's and your gauge is off? (just exploring every possibility)
PIP - profile ignition pickup....tells the computer where #1 is and most importantly controlls the ignition timing. If it was flakey....might cause ignition issues which might explain why your getting a "flooding" condition (because your not igniting the fuel)
ACT = air charge temperature. used in calculating air fuel ratios (one of many variables used).
Oh, what is timing set at. Is the spout in when running? If missing would run like a 3 legged dog.
Cap and rotor good?
OK TPS code. What number? what is your tps voltage at idle? If above 1v then the computer thinks your on the gas pedal an will ENRICHEN the mixture. This means the injector pulse is lengthened, flowing a greater fuel volume. Your plugs would be rich smelling in this situation. I would focus on this.
Do not underestimate the control the sensors have on the running condition of your motor.
Also, how does the distributor gear look? is the distributor set to TDC #1 on intake stroke?
Is it possible ther is a rag or rags in the upper plenum or the lower plenum. My friend recently found two rags in his lifter valley from a mechanic visit 6 months earlier.
Good luck
I doubt it's fuel starvation. Are you hearing any detonation (pinging). If not then it's not likely to be fuel starvation.
What numbers did you get on compression?
Are your headers glowing or getting very hot? what is your operating temp at after 20 minutes of idling?
How are you measuring your RPM's? Stock gauge or aftermarket? Is is possible it's actually reaching 6250 rpm's and your gauge is off? (just exploring every possibility)
PIP - profile ignition pickup....tells the computer where #1 is and most importantly controlls the ignition timing. If it was flakey....might cause ignition issues which might explain why your getting a "flooding" condition (because your not igniting the fuel)
ACT = air charge temperature. used in calculating air fuel ratios (one of many variables used).
Oh, what is timing set at. Is the spout in when running? If missing would run like a 3 legged dog.
Cap and rotor good?
OK TPS code. What number? what is your tps voltage at idle? If above 1v then the computer thinks your on the gas pedal an will ENRICHEN the mixture. This means the injector pulse is lengthened, flowing a greater fuel volume. Your plugs would be rich smelling in this situation. I would focus on this.
Do not underestimate the control the sensors have on the running condition of your motor.
Also, how does the distributor gear look? is the distributor set to TDC #1 on intake stroke?
Is it possible ther is a rag or rags in the upper plenum or the lower plenum. My friend recently found two rags in his lifter valley from a mechanic visit 6 months earlier.
Good luck
i have been changing fuel pressure constantly, headers did glow when i first got it but that only happened once. stock and autometer tach read the same, ive changed the distributor three times so i dont think that would be the problem, it will idle good for 30 sec- to a minute then stalls. has new cap and rotor. actually this may sound dumb but ive never heard of checking voltage on the tps. how do i check it. thanks
bgjohnson
Founding Member
where exactly was your MAP sensor when you replaced it? you do know that you have a MAF right?. Speed density used the MAT(measure temperature) and MAP(to determine load) to regulate air/fuel ratio's. The MAF only has the MAF to regulate the air/fuel ratio by having 2 thin wires in the MAF, one(heated wire) provides voltage readings proportional to the mass of airflow into the engine. the other wires measures temp. so whatever sensor you think you replaced it wasn't the MAP sensor.maybe that's your problem, you replaced somthing that wasn't there.
EDIT: unless that computer that's in there uses both, which would be very very odd, oh and the TPS sounds like it is way off. that's the only other thing I could think of
EDIT: unless that computer that's in there uses both, which would be very very odd, oh and the TPS sounds like it is way off. that's the only other thing I could think of
another possibility is improper valve adjustment. when checking compression the lifters arent fully pumping up giveing you a reading.
after vehicle is started and running they pump up fully and can be holding valves open slightly accounting for the backfire into the intake and erratic idle, and unwillingness to rev up.
i'd pop a valve cover and readjust a bank and see if you have the right lifter preload.
ive experienced the same problem 15 years ago after putting a 302 together after getting it back from the machine shop. if thats the problem then a shim kit will get you back on the road.
ecspecially so if you had the heads reworked. ie reground seats, milled, etc........
after vehicle is started and running they pump up fully and can be holding valves open slightly accounting for the backfire into the intake and erratic idle, and unwillingness to rev up.
i'd pop a valve cover and readjust a bank and see if you have the right lifter preload.
ive experienced the same problem 15 years ago after putting a 302 together after getting it back from the machine shop. if thats the problem then a shim kit will get you back on the road.
ecspecially so if you had the heads reworked. ie reground seats, milled, etc........
Stupid question, did you check the timing? I suspect that you may have a chain that is not 100% if this is true it will be out by 15* per cog but probably wont run at all if its out more than 15*. And when you changed the distributor did you also change the PIP. I have had this problem before, it would rev to about 3500 or so then it felt like it hit a rev limiter. Started farting and burping and just being obscene. Turns out the coil was shorting the PIP (ignition module on the distributor) so I changed the pip and coil and all was good.
Also MAF cars do have a map sensor but it used as something else it is now a BAP sensor (barometric air pressure) which is a map sensor without manifold vacuum (you didnt hook up a vacuum line to it did you? That would be all bad).
Anyway some more thoughts for ya good luck and dont give up
Kevin
Also MAF cars do have a map sensor but it used as something else it is now a BAP sensor (barometric air pressure) which is a map sensor without manifold vacuum (you didnt hook up a vacuum line to it did you? That would be all bad).
Anyway some more thoughts for ya good luck and dont give up
Kevin
Similar threads
