78 924 lacking power top speed is 30 mph!

jbone28 · 04-21-2002, 10:23 PM

Hello everyone ..this is my first post..sorry it is a tech question though..

Heres the delima...I just bought a 1978 924 and the top speed is..like I said 30 mph? Is this a common problem...Im thinking it is Fuel injection or fuel filter problem?...Just wondering where to start...compression? Spark? Any suggestions would be greatly appreciated...Justin

Rollins · 04-21-2002, 10:55 PM

Sounds jacked up. Check the compression and check that all the cylinders are in working order.

jbone28 · 11:10 PM

yea was going to do try that first...also It is overheating..I would think it was a timing issue exept It fires right up...Oh P.S. could this be a vacum prob. like leaky hoses?...I read somewhere about air in the fuel...My fuel tank does leak really slowly right under the tank sending unit?

wolfrpi · 04-22-2002, 12:39 AM

I just had a 944 removed for $100. Food for thought.

Lawrence Coppari · 04-22-2002, 03:58 AM

Clogged cat?

Eturbo924 · 04-22-2002, 04:40 AM

What do you mean by overheating? Is the temperature guage pegged? is the header glowing?

I would check to make sure you do not have a blown head gasket. If the car is overheating and has no power it is likely a blown head gasket. It can also be inproper cam timing.

Question. Does the motor not rev abover a certain rpm even at idle?

My first guess would be head gasket though. So inspect the oil and coolant and do a compression check.

Eric
www.geocities.com/eturbo924

Cebu · 04-22-2002, 04:53 AM

I too, suspect a clogged catalytic converter/exhaust system as a primary place to start looking for the lack of speed in conjunction with engine over-temp.

jbone28 · 07:07 AM

Just a couple of things I forgot to mention..sorry...I purchased this car yesterday drove about a blockand It overheated so bad that the a hose blew the small one that is 2 inces reduced to 1 inch right near a water pump..After further inspection i noticed the two fans were not plugged in! Could this have been the reason for the melt down?.. And I would suspect the cat too but It is unhooked..just before the cat
just straight pipe...In my experiance with a blown head gasket the oil is usually greyish or the cap has water spots or the car puts out black smoke right?....I have none of these issues? Hey eturbo Ill check that rpm issue this moprning and reply back....Thanks everyone for all the fast responses...Hope I can get here running...Im startin to worry here

Eturbo924 · 04-22-2002, 07:50 AM

Did it blow the hose at the thermostat housing? Could be a failed thermostat. This would definately cause the car to overheat very qickly. The fans are not really needed on a reasonable day (heat wise) as long as the car is moving and is running properly. Can you take a photo of the hose that blew so we can see the exact location?

I would get the fans working though.

Eric

drew1 · 04-22-2002, 01:27 PM

jbone,

Welcome to the board. I'd follow everybodies advice, do a compression check & get a thermostat. I think fans not running was overheating problem.

Then I would check fuel pressure, system & control. Next I would check fuel volume. If these are low, get a fuel filter & recheck. If the car has been setting for a long time you might want to check injector spray, too.

drew1

jbone28 · 04-22-2002, 07:04 PM

Hey everyone..Thanks for all the replys..This is turnin out to be a great board..Sorry for the delay in replying and also I am am sorry I had no chance to check compression or anything else for that matter..Worked 13 hours today...I roof ..in CA...Dog tired..Cant work on the car although I want to with all thats left in me!.....I think ill just go sit in there and think...lol

Ok heres the picture of the hose that blew..

http://www.pelicanparts.com/catalog/images/jamal_image_1/E10624103.JPG

Its from this web site I think this is it...Mine is a little shorter?

Im going to try and muster the strength to start the car..and check that Rpm thing...Ok maybe I can look under the hood..lol

Ya see how they getcha..I like tinkering as much as the next guy but cant wait till shes runnin!

jbone28 · 08:31 PM

Update...that only took 5 minutes that wasnt so bad

Ok heres the results...When it first started the farthest I could get the RPM's was 4000 30 seconds later 3000 then 2000 this is floored!
If I let up on the pedal there is a slight rise but only slight....Could this be a fuel prob?..also how can I test the fuel filters? can the original fuel filters be replaced with say the ones from pep boys?..this is how chevys work..Im sorry Im just new to the porsche thing...I still have to check compression

drew1 · 04-23-2002, 12:25 AM

You can test the filter by checking pressure & flow. If Pep Boys or whereever has the style to fit it would work. Somefilters don't have as fine a filtering media as others or as much media. Therfore some may let by particles others don't and stop up quicker.

drew1

jbone28 · 04-24-2002, 06:56 PM

ITS FIXED!!!!! Happy day! after further inspection and tinkering there was a cat!...Stupid me...I thought the pipe was cut before the cat but turns out it was after...geez its little..anyway I pulled it off..and it runs...oh get this I took it for a spin..louder than hell.(no pipe)neibors are pissed!it was much better kinda like a honda accord..as far as speed ..but i was just happy it was going faster than 30..I get home and decide it should be faster right...so I go to pull a plug wire to check the cylinders and realized that earlier I had taken one off and not put it back!...I was test drivin on 3 and happy with the results..lol..Put it back and layed rubber allthe way up the drive..dammn its fast!..Anyway thanks everyone for the help...another satisfied customer!

fty · 04-24-2002, 07:25 PM

Congrats on the find.....you got lucky could have been bad news...have fun with the 924 best regards-chris