Need help on a few issues
05-27-2015, 09:03 AM
#1
Thread Starter
Join Date: May 2015
Location: Colorado
Posts: 7
Need help on a few issues
So I'm looking to the forums for a little guidance and advice as I am at my wits end trying to figure out whats going wrong with my 5.0. The project started by swapping to a E303 clone cam, 70mm throttle body, gt40p intake, professional products 10000 series distributor, 24lb injectors and MAF, Short tube headers, 2.5" offroad H-pipe, cold air intake, and replacing the harmonic balancer. The heads are factory E7 (springs changed for cam). Car is an automatic with 77k miles. Timing set at 12 degrees base.
I'm far from new to the game as far as fox bodies go and have pretty extensive experience working on them. However, this one has me a bit stumped.
The car studders (best way I can think to put it) below 1500 rpm, and won't keep an idle even after numerous attempts at finding any vacuum leaks.
I've changed the intake gaskets (Set) about 4 times, changed every hose, and still can't seem to get the car to run right. It idles anywhere from 500 rpm to 1100 rpm. I've gone through the idle setting procedure more times than I can count, changed the ACT sensor, TPS sensor, MAP sensor, fuel pressure regulator, and MAF sensor. The car isn't kicking out any codes through KOEO or KOER
The car is sucking oil heavily through the PCV valve into the intake, again won't idle anywhere consistently, and occasionally backfires through the exhaust. And of coarse there's the stutter.
Any advice?
I'm far from new to the game as far as fox bodies go and have pretty extensive experience working on them. However, this one has me a bit stumped.
The car studders (best way I can think to put it) below 1500 rpm, and won't keep an idle even after numerous attempts at finding any vacuum leaks.
I've changed the intake gaskets (Set) about 4 times, changed every hose, and still can't seem to get the car to run right. It idles anywhere from 500 rpm to 1100 rpm. I've gone through the idle setting procedure more times than I can count, changed the ACT sensor, TPS sensor, MAP sensor, fuel pressure regulator, and MAF sensor. The car isn't kicking out any codes through KOEO or KOER
The car is sucking oil heavily through the PCV valve into the intake, again won't idle anywhere consistently, and occasionally backfires through the exhaust. And of coarse there's the stutter.
Any advice?
05-27-2015, 11:18 AM
#4
4th Gear Member
Join Date: Nov 2006
Location: CA
Posts: 1,670
You’ve been throwing parts at the problem with no luck. Its like throwing darts in the dark and hoping to hit a bullseye. As you can see it is a waste of time & money.
If the PCV valve is clogged it can cause issues, but I don’t think it would cause the issues you are seeing. If yours is sucking up a lot of oil you might want to invest in an oil separator on the PCV hose.
Either way, I would put down your wallet and hook up a scanner to check the short & long term fuel trim numbers at idle & at 3k RPMs. It is most likely a rich or lean condition at idle. The direction to go will depend on those numbers. That is of course if a ’93 era car with ODBI has those numbers available.
Good luck...
If the PCV valve is clogged it can cause issues, but I don’t think it would cause the issues you are seeing. If yours is sucking up a lot of oil you might want to invest in an oil separator on the PCV hose.
Either way, I would put down your wallet and hook up a scanner to check the short & long term fuel trim numbers at idle & at 3k RPMs. It is most likely a rich or lean condition at idle. The direction to go will depend on those numbers. That is of course if a ’93 era car with ODBI has those numbers available.
Good luck...
05-27-2015, 01:24 PM
#5
Thread Starter
Join Date: May 2015
Location: Colorado
Posts: 7
You’ve been throwing parts at the problem with no luck. Its like throwing darts in the dark and hoping to hit a bullseye. As you can see it is a waste of time & money.
If the PCV valve is clogged it can cause issues, but I don’t think it would cause the issues you are seeing. If yours is sucking up a lot of oil you might want to invest in an oil separator on the PCV hose.
Either way, I would put down your wallet and hook up a scanner to check the short & long term fuel trim numbers at idle & at 3k RPMs. It is most likely a rich or lean condition at idle. The direction to go will depend on those numbers. That is of course if a ’93 era car with ODBI has those numbers available.
Good luck...
If the PCV valve is clogged it can cause issues, but I don’t think it would cause the issues you are seeing. If yours is sucking up a lot of oil you might want to invest in an oil separator on the PCV hose.
Either way, I would put down your wallet and hook up a scanner to check the short & long term fuel trim numbers at idle & at 3k RPMs. It is most likely a rich or lean condition at idle. The direction to go will depend on those numbers. That is of course if a ’93 era car with ODBI has those numbers available.
Good luck...
Given that I'm getting no codes, that is what makes this quite a conundrum. O2 would be giving a code for lean or rich as well. Thus, the throwing darts.
05-27-2015, 04:04 PM
#6
2nd Gear Member
Join Date: Feb 2007
Location: IA
Posts: 258
About the oil being sucked through the pcv do you have a fresh air supply from you cai or throttle body to the valve cover? I know a lot of cai and aftermarket tb´s don't have a provision for filtered atmosphere air. I've also personally made the mistake of having two vacuum sources on my crankcase instead of just the pcv and an atmosphere source.
05-27-2015, 09:21 PM
#7
Thread Starter
Join Date: May 2015
Location: Colorado
Posts: 7
About the oil being sucked through the pcv do you have a fresh air supply from you cai or throttle body to the valve cover? I know a lot of cai and aftermarket tb´s don't have a provision for filtered atmosphere air. I've also personally made the mistake of having two vacuum sources on my crankcase instead of just the pcv and an atmosphere source.
05-28-2015, 04:51 PM
#8
2nd Gear Member
Join Date: Feb 2007
Location: IA
Posts: 258
Have you checked your timing with a gun or just feel? It's easy to get a tooth off on the distributor, again, from experience. Start with the basics: spark fuel and air. What is fuel pressure at? How strong is the spark and how do the plugs look? I know youve changed the MAF but oil from K&N filters can make those dirty in a hurry. Also these cars are notorious for having bad connections, especially the two "salt and pepper shaker" ten pin connectors on the passenger side of the intake.
05-28-2015, 05:25 PM
#9
Thread Starter
Join Date: May 2015
Location: Colorado
Posts: 7
It would appear I have my answer, I just got off the phone with a mustang specialist, and I'm told that I have to run a chip and have the car tuned. Because a factory MAF off a cobra isn't calibrated for injectors, it's calibrated for the specific computer. This MAF is off a 97 cobra. I'm told pre 94 mustang the ECU controls flow to injectors, the MAF only assists with the A/R mixture. Apparently 95 up it is stored via ecm. So essentially the aftermarket MAF's are calibrated to fool the computer, thus why they are effective. unfortunately, this is gonna cost me $600+
