odd sort of hesitation
 

Getting kind of an odd hesitation on throttle. It was only slightly there after I got done working on the car, I figured it may be the plugs I put in so I changed them out. Stayed the same.

Basically, right after a shift as I get on the throttle it feels like the power isn't quite all there. At higher rpms it's fine. Lower rpms it isnt'. Say i'm at 3k and put my foot down, it generally feels like the power is there and snappy, but gradual acceleration feels weak at times.. Anywhere from 2k to 2.5k it is super sluggish to respond unless I just put my foot down, then it seems to react and it's fine.

A couple things I'm considering:

- Vacuum leaks? I replaced pretty much all the vacuum lines on the car except the main airbox hose.
- Fuel issue? Weak pump maybe?

When did you last replace the fuel filter?

Remove the filter and check the strainer for debris. If clogged, unclog and swap next oil change.

When was the alst time you swapped the Cap and Rotor, check that as well. Bentley shows the proper Ohms you will be looking for.

Cap/rotor/wires/plugs all replaced at the time I did the clutch in the engine out maintenance. And it ran like a top for like a week, felt like a new car. Then slowly has developed this off the wall hesitation. I'll do an ohms check on the cap and rotor just to be on the safe side. I didn't think to check the fuel filter, very possible.

A couple of recent threads found the strainers were clogged at the fuel filter. Hope this is the case for you. at higher RPMs the the flow may be high enough as not to effect it but at lower RPMs a clogged Fuel Filter could starve her of fuel.

Didn't you or the wrench have to disconnect the fuel line to drop the engine? O2 would have oxidized and hardened the debris. Just a guess here.

Yes, absolutely did have to disconnect to drop the engine. It was out for several days, so this is definitely a possibility. That makes sense. I'll get a fuel filter and replace it. Thankfully they don't seem to piss fuel when removing them so it's an easy thing to do on these cars. What you're describing makes a lot of sense, it sort of feels strong/weak/strong/weak depending on throttle, so that makes sense that high flow at higher rpms may ignore it.

I didn't intend for you to throw money at it, try checking the strainer first just to make sure unless you know when you replaced the filter last. Just my 2 cents.

How is it at idle?

You may have a vacuum leak at the intake gaskets.

How do I check the strainer, does the fuel filter come apart or is there a piece that simply cleans out? I just recall disconnecting the fuel lines to drop the engine.

Seems to idle fine. Sometimes it idles just a wee little hair high, but for the most part, idles and runs fine.

Remove and use compressed air to blow threw the out port, on my 3.2 it has an arrow sprayed on the outer shell. Place a paper towel on the inlet. The debris wil be evident. If not, you saved some money and will need to look some where else.

Before that look in the fitments.

Gotcha, I'll do that tomorrow in the morning. Thanks man!

Just spent months tracking down a similar problem - changed a bunch of things mainly because they were old and I wanted to update eliminate possibilities. Did fuel injector clean, new head temp sensor, new distributor cap,rotor, new fuel pump, filter and plugs. All improved but the problem ended up being leaks around inlet manifold. I only found it by spraying carby cleaner directly at base of inlets whilst shining a high intensity led torch (whilst car idling). Total parts for inlet gaskets $24.00 labour 2 days of my time.

Vince,

If it ends up being something along those lines is it an engine out type maintenance or can it be done with the engine in? That's a good point on testing it since the idle would raise I'd assume. I'll try this as well.

What year car is this?

The 82' in my siggy. 3.0

Yeah, I'm on mobile version so the sig doesn't show.

I'm of no help though, don't know the CIS cars.

My mechanic quoted me 6.5 hours work (@$110 p/hr). Im doing it this weekend - engine in!
Have a search on inlet gasket replace. there is some good threads on the problems and pitfalls. I also used my mechanic to test for leaks with a smoke machine to diagnose problem
An additional note - when I sprayed carby cleaner at each inlet I could see the cleaner being sucked in. The auto adjust on idle (87 911) meant mine idled ok anyway.

Hope this helps