some 944 engine issues

[vwhammer]

Howdy there.
I am new to the whole Porsche thing and I have a couple issues with my 88 944
The first thing is what sounds like a lifter ticking (more like a knocking) when I first start the car after it sits for a couple of hours.

The car has a little over 150k on it and perhaps the lifters are leaking or something like that but I thought I would see if it is a common thing and what the fix might be.
Obviously changing the lifters is the first thing but I just want to make sure it might not be something else first.

My second issue is a slow reving engine.
This may sound stupid and it is a difficult thing to explain (or maybe it isn't) but I will tell you what it is doing and maybe someone can give me some input.

To put it simply the engine just does not pick up from idle as fast as I would expect it to.

It idles around 900 rpm and when I give it gas it just revs a little slowly until you get up to around 1500-2000 rpm.

Now normally I would associate this with an ignition timing issue but as this car seems to have no method to adjust the ignition timing I don't know how to fix it.

It seems to do fine once I get it moving but something just isn't right.
anyone else have this problem?

Here is my beater in question.
It's a little rough around the edges but I have big dreams for it someday once I get a couple of other projects out of the way first.

[Britwrench]

Cold engine knocking is a sign of loose timing belt, when was it changed or last adjusted?

Could be the lifters, listen where the noise is coming from.

Use a Porsche or Mahle oil filter too.

[2Tight]

Good advice so far. What weight oil is in the car? Anything less than 20W -50 has resulted in noisy lifters for many owners. If you don't have the history on the TB belt you really have to change it out. The other bad news is that even the new Porsche supplied INA lifters have a bad track record so far, if it has a Fram or odd ball oil filter dump it and get a Mahle or Purolator 1. Last but not least, don't confuse noisy injectors with a bad lifter...Bosch injectors are very loud.

[vwhammer]

The lifter knock or tick only last for about 5 seconds when I start the car after it has sat for a while.
Is that still a timing belt issue?

I would guess that the timing belt needs changed and I don't have a problem doing that but this tick is really annoying.
I just purchased the car and the oil change is the first thing on the list.

Anyone have any ideas on the slow revving issue?

[John_AZ]

Originally Posted by vwhammer

Howdy there.
The car has a little over 150k on it and perhaps the lifters are leaking or something like that but I thought I would see if it is a common thing and what the fix might be.
Obviously changing the lifters is the first thing but I just want to make sure it might not be something else first.

My second issue is a slow reving engine.

Welcome.
You may just need to clean the lifters with a can of SeaFoam. Since you have to change your oil and get a new filter anyway, this may solve the ticking noise.

Please change your cam belt-now. $12 is cheap for a belt. $1000 for a new head and valves (parts+++++++) if the belt breaks. YMMV

Rough is beautiful when finished.

JOhn_AZ

1988 924S + 1987 924S

[Tidybuoy]

Since you say it ticks and then goes away, it sounds like lifters, how's your oil pressure during this time?

Seafoam is a good start, it really cleans the engine but do this before changing your oil.

Injectors tick and this is normal. Pulse injection means you have electrically opening/closing injectors and they make noise.

I had an exhaust leak once that sounded like lifters. Even my mechanic thought it might be lifters. It turned out to be one exhaust nut was loose (the one closest to the fire wall).

Lastly: we have the same car (color & everything):

[vwhammer]

The oil pressure jumps right up upon starting but it is tough to get any type of accurate reading in the short amount of time that it knocks.
After listening to it again it seriously only ticks for less than 2 seconds and I am pretty convinced that it is a lifter or lifters.

I will do the seafoam thing and change the oil and T belt.

Now I just need to figure out the slow revving issue.
As I said it is only in the first 500 RPM or so from its idle point of around 850-900 RPM.
It may be better to just say that the throttle response is less than ideal because although it revs slow from idle it is also not very responsive while bliping the throttle for downshift rev matching.

Maybe the seafoam will help sort this out or maybe the timing belt.
This car needs a lot of little things taken care of and I will just knock them out one at a time until it works the way that I think a Porsche should.

[speedracing944]

I would double check you spark plug wires. Make sure they are all connected and tight. Those aren't stock wires so I would start there. You could also check your cap and rotor.

Speedy

[Tidybuoy]

I would also change the fuel filter. This is just a basic maintenance item and should be done about every 10k miles. There's also a fuel screen in the bottom of the tank and can get clogged. It's best to change this on an empty tank as fuel will spill everywhere.

My car was running fine but I decided to clean the fuel screen anyway and I was surprized how dirty it was.

A clogged fuel filter will cause a lack of power as the engine is being starved of fuel.

Vern

[vwhammer]

While the car is not blisteringly fast it is about as fast as I would expect it to be for the power it is rated at.
So, I would not say it is down on power just a little sluggish in the lower RPM range.

Of course I have never driven one before so maybe it should be much faster.

As I said I have a lot of little things to fix/replace and all of these things that are being mentioned are the types of suggestions I was looking for so keep them coming.

[John_AZ]

vwhammer,

A couple of suggestions that may be appropriate unless you are hiding the fact your skills include blueprinting race engines.
1. We use www.clarks-garage.com alot.
Good information and easy to read.
2. The above suggestions are baby steps for a new 944 owner.
Except for the suggestion about the cam belt which usually terrifies a new
owner into spending hundreds on labor, belts, rollers,seals. You had no
reaction.
3. Moving forward, I would do all above and then begin the task of checking
the TPS-Throttle Position Switch as covered in Clarks-Garage.
http://www.clarks-garage.com/shop-manual/fuel-06.htm.
I noticed a bit of rust and white corrosion in the engine bay. This could have
changed the contact positions on the TPS.

I did enjoy your term of "blisteringly fast". An 8 passenger mommy van will beat you at a red light. The thrill is my ride from Phoenix to Flagstaff on I-17. 75mph? and twisty.

A lot more to come...

John_AZ
1988 924S + 1987 924S

[vwhammer]

I do perform all of my own work and I WAS an ASE certified technician (I didn't take the recertification tests).

I have done the usual old Chevy and ford builds in the past and my current area of interest, other than Off road vehicles, is VWs and Audis (usually performance oriented builds)
I have all of my own answers to most of the problems that plague my dear old Porsche but, as a new Porsche owner, I thought I would see if there were any common problems/fixes before I do what I think I should do.

I will definitely check out the links and you will surely find me on here regularly asking all sorts of silly questions.

Knowledge is power and any plain Jane 944 owner can probably tell you that more power is always a welcome addition.

[robm-951]

With regard to the lack of throttle response, you are probably not used to the nautilus shaped throttle cam. You can buy an aftermarket one that is completely round or modify yours to work the same as a round one.

To modify yours, take it off and re-drill a new center hole and throttle cable end barrel hole and slot into the cam 90 degrees counterclockwise to their current location. This works just as well and is really easy to do.