2002 Focus no power won' rev up, Code p1507

My 02 Focus intermittently bogs down and I can not hear the engine rev as I depress the gas.No power to take off. The car does not stall, but I have to baby it till the engine "catches". Once I can speed up the symptom goes away. I do not have a check engine light on , but there was a code P1507(IAC).

I'm having that exact problem right now. Every mechanic I know is scratching their head. When mine "catches" after babying it takes off like a raped ape. Did you ever find a solution??

poss vac leak? vct problem?

more info. when you say it "catches"???? what rpm? does it slowly climb then take off? ifso what rpm? any surging?

The thing idles great, then I have to baby it to like 3800 to 4000 rpm then boom it has power. It's like having too fat of a needle in a carburator and metaphorically speaking it runs great on the mains but has no midrange ... it has 108,000 miles on it. After the problem I changed the belts checked and adjusted valve clearences put new plugs and wires changed fuel filter checked fuel pressure thinking it was only the fuel filter. Also it's a manual trans. not that that matters.

The thing idles great, then I have to baby it to like 3800 to 4000 rpm then boom it has power. It's like having too fat of a needle in a carburator and metaphorically speaking it runs great on the mains but has no midrange ... it has 108,000 miles on it. After the problem I changed the belts checked and adjusted valve clearences put new plugs and wires changed fuel filter checked fuel pressure thinking it was only the fuel filter. Also it's a manual trans. not that that matters.
oh...i did look for vaccuum hoses off and didnt see any but they are hard to pick out sometimes

the p1507 is iac over speed. check the resistance at the solenoid, should be 6-13 ohms. unplug it and see if the rpm changes at idle.
what is the fuel pressure? do you have a variable cam timing problem? maybee the timing belt jumped a tooth. see if timing belt is loose. timing belt should have been replaced at 60k. it is a wear item.

unless he has a SVT, he doesn't have variable cam timing

sorry I didn't actually post this thread...I heard his gentleman's description of problems and found mine to be similar and was asking his solution.....I haven't any codes. I have oxygen sensors bypassed and other stuff changed in my engine. I just unplugged my diablosport chip and am headed to the mechanic to get some codes now. My zx3 isn't a SVT and the problem still exists as I described it. I'm thinking MAS. Fuel pressure I'm told was around 40 psi. As I said earlier the timing belt is new as of last week.

sorry I didn't actually post this thread...I heard his gentleman's description of problems and found mine to be similar and was asking his solution.....I haven't any codes. I have oxygen sensors bypassed and other stuff changed in my engine. I just unplugged my diablosport chip and am headed to the mechanic to get some codes now. My zx3 isn't a SVT and the problem still exists as I described it. I'm thinking MAS. Fuel pressure I'm told was around 40 psi. As I said earlier the timing belt is new as of last week.


maf is poss. clean it. do you still have the cats. on this? if so, check back pressure, if over 5psi something in exhaust plugged. have seen same complant on trucks and have found plugged cats, but not that concern/problem on cars. its allways poss.

codes said computer....i think because of chip. wrote diablosport.waiting for reply. going to clean MAF with electronic parts cleaner..last i saw it it didnt look dirty. no grime stuck to inside intake walls.

Is it a manual? Cus, it sounds like you are describing a clutch slipping. Just another something it could be...

Not the tranny.
Funniest thing though. Put new MAF and still a problem. I swear I must be the only person in the world with this problem!

still seems like fuel pressure i would first check cat back pressure to make sure thats fine.then hook up fuel gage and vacume gage and scan tool to check tp reading.then drive it with all hooked up i think youll find at time problem happens fuel pressure is around 22psi, clogged pick up screen on pumphttp://www.automotiveforums.com/vbulletin/#
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