Focus Fanatics Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
Hello everyone. I have just finished my engine swap in my 2003 ford focus zx3 and after starting up the car it idles around 2kRPM and then after 10sec later jumps straight up too around 4kRPM I spent a whole day seeing if I did anything wrong or left anything unhooked. I even did a vacumn leak test by pushing smoke into one of the vacumn lines and spraying starter fluid around all seals example intake manifold, throttle body, vacumn lines. Anyways I know the IAT is built into the MAF sensor so I decided too unplug the MAF sensor and now my car idles fine. Before it idled so bad that if I was in gear and took my foot off the brake the car would take off! So in conclusion I believe it is a really bad MAF and IAT giving false readings and when I unplug the sensor the car just goes too its pre-determined map. What is everyone elses thoughts on this?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #2
Hello everyone. So I believe it is a mixture of problems. This engine swap couldn't get worse... So the car came back with a code for an open circuit on the IAT. So I replaced the MAF sensor with one out of a junkyard. Great car idles fine. BUT the second I press the gas pedal the car shoots up too 4k rpm and steadily holds there until I shut it back off and let it sit for 5min. This is a weird one. I have no vacumn leaks I even checked. All my intake seals are brand new. The IAC is working fine and the car now only has one code p0122 tps sensor low voltage. So I replaced the TPS sensor still the car will jump too 4k rpm if I press the gas. But if I unhook my MAF sensor it idles like shit but won't jump all around the place. I am completely confused it does it if the engine is warm or cold if it's running for 5min or 30min. My injectors O-Rings are new all new injectors, timing belt replaced with all new pulleys, belt drive completely replaced it even has a new AC compressor and waterpump, New spark plugs, new wires, new coilpack, all new gaskets and seals for the engine but the head gasket, brand new FSWERKS racing exhaust from the catback even replaced the flex pipe and new exhaust seals, new engine mounts and all new fluids. It even has some brand new suspension parts. Any focus guru I would really appreciate your input on this!
 

·
Registered
Joined
·
28 Posts
Discussion Starter #3
Car runs the same if I unhook the TPS sensor, IAC valve(will die after a while), coolant temp sensor, knock sensor, oil pressure sensor, o2 sensors and if I create a vacumn leak.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #4
I just replaced the TPS sensor. I had one that came with the new engine and it sitll ran the same so I decided too just bite the bullet and go too autozone and buy a new one the car still runs the exact same so at least I know that p0122 code does not have much truth too it. The car still idles at 4kRPM but if I unhook the MAF sensor it idles fine.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #5
Tomorrow I am going too unbolt the intake manifold and try deep cleaning everything? Maybe something is getting stuck somewhere. I am at a loss here. I used the IAC valve off of the new engine so I am going too try too swap it out with the old one sense I knew that one worked Just for shits and giggles, Even though we both know an IAC can not cause an engine too idle at 4kRPM and hang there even when unhooked. and too prove myself there was no vacumn leak I unhooked ALL vacumn lines too the intake manifold and plugged the holes. THE CAR STILL RUNS THE SAME. Does not matter if all vacumn lines are open or plugged it will have a hard time starting if they are open but always idles at 4k RPM
 

·
Registered
Joined
·
87 Posts
If it is idling fairly well with the MAF unhooked but goes to pit after it’s hooked up, it sounds like something related to the MAF.

I know you got your “new” MAF from a junkyard...maybe the “new” isn’t functioning properly?

Could it be something with the wiring between the MAF to the computer not allowing the computer to accept the MAF readings properly?
 

·
FF Affiliate
Joined
·
30,479 Posts
Need to do a datalog , your guessing , do you have a SCT X3 or X4 so you can datalog ?

What swap did you do ? What Mods ?

Tom
 

·
Registered
Joined
·
28 Posts
Discussion Starter #8
Completely winging it here. I have no Datalogging tools. The car is completely stock other then the exhaust. I just replaced the blown 2.0 zetec engine with another 2.0 zetec. The car will idle fine until I do anything that puts an load on the engine. ex: reving engine, turning on AC, turning steering wheel, adjusting radio volume.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #9
While the engine is running I hear a loud whistling sound but I do not have an air filter on for testing purposes. After unhooking the battery and letting the car sit all my codes went away and I took it for a drive. None of the codes came back but the car will still try too idle at 4k RPM even driving it is dangerous due too it takes off and when you take your foot off the gas the car will still accelerate. While driving I did notice that it was popping a lot out of the exhaust almost like a backfire. Is it possible that the computer on it's own can rev the engine to 4k RPM even with the throttle body closed? This car has sat with the same gas in it for about 7 months. Could the gas be bad and causing my high idle?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #10
I did not get around too working on the car that much today. Tomorrow I am going too try too diagnose it some more. The new engine for my car came out of a 2.0 zetec with an automatic, My car is a manual. I swapped over the crank sensor and sensor bracket because I noticed that was different. The intake manifold looks like the exact same as the one that came of my old engine and I decided too use the new one due too my old one had blown engine oil and coolant in it. Is there any other differences from the automatic focus too the manual focus that could cause something like this??? they were both 2003 engines
 

·
Registered
Joined
·
28 Posts
Discussion Starter #11
So today I decided for shits and giggles too replace the IAC with one of my old engine because I knew that one worked. STILL RUNS THE EXACT SAME. I took the intake manifold off the engine checked the seals all were good and still looked brand new. I checked the throttle body gasket still looks good and brand new I pulled the injectors out the O-Rings look new. If I take a piece of plastic over the throttle body the engine dies so I know for a FACT now it is not a vacuum leak. Serves me right for buying an American car. My mustang did the exact same thing as this car? Do all of them do this???? I am fucking pissed and ready too just junk the car which sucks because I have put a ton of money and new parts onto it. I was really hoping I could keep it and drive it for at least 5-6 years before I had too get rid of it. It did not even make it out of the garage. Could a faulty computer cause something like this??? The second I unhook the MAF it runs fine but I know the MAF works. The old one worked fine on the old engine and the new one came out of a junkyard explorer so it's possible that one is bad but the old one worked fine until now. It just does not make any sense that with the MAF plugged in it will idle fine until I do anything like turning on the AC or moving the steering wheel or even just turning up the radio
 

·
FF Affiliate
Joined
·
30,479 Posts
Taping off the TB does not eliminate a Vac leak ! FACT

Smoke test and find a SCT X3 or X4 to do a datalog with

Is the mass air flowing the correct directions ?

Tom
 

·
Registered
Joined
·
1,047 Posts
The new engine for my car came out of a 2.0 zetec with an automatic, My car is a manual. I swapped over the crank sensor and sensor bracket because I noticed that was different. The intake manifold looks like the exact same as the one that came of my old engine and I decided too use the new one due too my old one had blown engine oil and coolant in it. Is there any other differences from the automatic focus too the manual focus that could cause something like this??? they were both 2003 engines
Did you use the engine wiring harnesses from your original engine?

Could a faulty computer cause something like this??? The second I unhook the MAF it runs fine but I know the MAF works. The old one worked fine on the old engine and the new one came out of a junkyard explorer so it's possible that one is bad but the old one worked fine until now. It just does not make any sense that with the MAF plugged in it will idle fine until I do anything like turning on the AC or moving the steering wheel or even just turning up the radio
What MAF are you running right now - the one from the original Zetec?

Paul
 

·
Registered
Joined
·
28 Posts
Discussion Starter #14
@Paul1958 Yes I am running the original harness and original MAF. It just does not make sense that with the MAF plugged in the car idles at 4k RPM like what kind of engineer would even think it is a good idea too let a computer hold the engine RPM that high when the throttle is closed???
 

·
Registered
Joined
·
28 Posts
Discussion Starter #15
The thing that blows my mind into another intergalatic wormhole it seems me the owner of a junk american made focus is the only person in the ever of history of the human species has ever had a car that idles high with the MAF plugged in. Apparantly this thing is magic because according too the entire interballs this should be impossible and unplugging the MAF on a ford should kill the engine immediately. If you google anything MAF high idle related nothing comes up. The only thing that brings the idle down is if I unhook the IAC or the MAF. but my IAC is working fine because as I said if you unhook the battery walk away for 30min plug the battery back in and start the engine up it will run fine until you do anything that puts a load on the engine for example press the gas and turn the steering wheel then all hell breaks loose and ford will show you what that 2.0 zetec is made of by uncontrollably screaming too 4k rpm until you either turn the key or unhook the MAF
 

·
FF Affiliate
Joined
·
30,479 Posts
No the engine shouldnt die if you unhook the MAF in all cases , if you unhook the IACV the engine should die every time if it does there is other issues
With MAF plugged in , IACV unnhooked whats your idle , if it is above 1000 rpm then you need to adjust the idle on the TB or you have a Vac leak

If your MAF going in the right direction ?

Have you done a smoke test

Tom
 

·
Registered
Joined
·
28 Posts
Discussion Starter #18
Yes my MAF is going into the right direction. I have done A smoke test. I did a Data log. My computer is detecting the throttle body moving correctly and when my foot is off the gas pedal it reads about 16.9 and there is no dead spots. My IAT is reading about 55.4 degrees which is probably is how cold it is in my garage right now currently raining and the garage is not heated or insulated. My MAF is working correctly too when the engine is running if I give it gas the readout increases and decreases when I take my foot off. My crankshaft position sensor is working correctly and so is my camshaft position sensor. the coolant when engine is off is reading 51.8. None of this makes any sense if all the sensors are working correctly. Why is the car doing this. There is no way this is a vacumn leak because if it was a vacumn leak it would do it all the time!!! But it does not do it until I put a load on the engine. The only thing that makes sense is that somehow both IAC are faulty. Now i got too take the intake manifold back off the stupid thing too replace it!! But how can the IAC cause my engine too hold the RPM at 4k and worst of all when I unhook it the car won't start!
 

·
Registered
Joined
·
28 Posts
Discussion Starter #19
I just want this problem too go away the amount of money I dumped into this thing I could of bought a way nicer better car then this. It has too be something that was changed when the engine swap was done because with the old engine it did not do this. Is anyone sure there is not something different between the an automatic focus and a manual focus other then the crankshaft sensor bracket.
 

·
Registered
Joined
·
1,047 Posts
It has too be something that was changed when the engine swap was done because with the old engine it did not do this. Is anyone sure there is not something different between the an automatic focus and a manual focus other then the crankshaft sensor bracket.
Engine wiring harnesses can be different - thats why I asked about the engine harness. Was ALL the wiring from the old engine swapped over to the new?

Do you have a DVOM? Check the VREF (5VDC) at the MAF connector (backprobe) with the MAF plugged in and unplugged KOEO.

Paul
 
1 - 20 of 22 Posts
Top