I am a new owner of a Porsche 914 1.8L . The engine has been running strong since I purchased this car about a month ago. Then one day after driving it an hour from my home it started misbehaving on my return trip after 15 minutes of the 60 minute drive back. The throttle seemed to stick and remain at the last RPM level. (sort of licke cruise control when you do not want it!) If I blipped the gas pedal, the rpm's still would remain at the higher level. I recall the rpm's would increase even further if I had it in neutral or the clutch in.

I replaced the accelerator cable, and by the looks of it, one would have thought it definitely was my problem. However, the condition persists. I then removed the throttle body and cleaned it thoroughly. After replacingf it and trying it again the high rpm's remained.

I then took a closer look at the Haynes manual and noted that their was a spring that went from the upper lever on the throttle body toward the rear 'firewall' lip between engine bay and rear trunk. I am missing that spring, so I tried to firmly push the upper lever away from the direction that the accelerator cable would pull the lower lever if one were to depress the gas pedal. When I pushed the upper lever there was no effect on the rpm's. When I pushed the lower lever in this manner this seemed to lower the rpm's, howver, it only lowered them a little.

I had been advised that my problem could be: (1) advanced timing (But would the timing actually slip/retard while driving?); (2) vacumn leaks before or after the throttle body; (3) the decel valve and/or the air regulator

I am totally inept in diagnosing and would appreciate any suggestions on how to
isolate these factors and test for each separately; ie. how do I check for vacumn leaks? how do I check the air regulator?, the decel valve?

I appreciate any advice and any further suggestions on other potential causes for this problem.

If I can not fix it myself I will have my mechanic check it out however, I would prefer to learn myself in case I get stranded in the future. Also my mechanis is booked and I want to be on the road!

Thanks in advance for any advice and your patience with a novice.

Chip

I haven't seen a 1.8 TB, only a 1.7 & 2.0 but they must be somewhat similar as to needing the return spring. This spring must be stout enough so as to return the butterfly within the TB to a closed position once your foot is removed from the throttle.

Some 2.0 TB's have a similar lever as you describe along with another lever that actually closes the butterfly within the TB. There is a very heavy duty spring between the 2 levers. The return spring must be on the lever that operates the butterfly or RPM's will not decrease.

Maybe someone here will have a photo of the springs needed on the TB.

........b

If you have a 1.8L, I will assume you have L-Jet Injection with a vane airflow controller.

1. Did the engine backfire at any time?

2. Is the seal on the oil filler cap deteroriated?

3. Any other vacuum leaks?

#1.....If the engine backfired, it can damage the vane airflow unit or the vane itself can start to stick due to being dirty.

#2 & 3.....Vacuum leaks on this system are not tolerated very well.

The spring is a supplemental return spring in case the one on the shaft breaks.

Hey.....just my guesses....

QUOTE (turtleman @ Jun 28 2005, 08:57 PM)

I am a new owner of a Porsche 914 1.8L ...... I then took a closer look at the Haynes manual and.... however, I would prefer to learn myself in case I get stranded in the future.....

From your post, you appear to be a perfect 914 owner...

Although I can't help you much at all, since my teener has carbs...

But anyway.... WELCOME!

To the asylum of the teener wizards and mad men!

We can't legally offer any meaningful help until you post a few PICS!

,,

could the pedal bushings be worn out?

with the above advice

QUOTE

If I can not fix it myself I will have my mechanic check it out however

does he know L-jet and 914's....or will he be learning on your car...and at your expense

if you're near Springfield Ma. I can take a look at it for you

Could it be possible that your accel. cable is wrapped around the clutch cable.
Can happen when feeding the cable through the tunnel. That will do the exact thing your talking about. Try re-routing the cable again before throwing dollars at parts you might not need. Pull up the floor board and depress the clutch with your hand and see if the cables bind. I had that problem with my 73.

Guys....if there's no spring .... put one on....springs are what? A buck, three eighty down at Manny Moe and Jack's?

MAYBE the TB has an issue...but nothing a gud spring won't help. If it still sticks...then there's another problem.

A new acceleaqrtor cable was installed and I took care not to wrap or tangle it with the clutch cable. I had read previous post mentioning that problem, as well as an email that had been sent to me directly, suggesting this as a possible culprit.

The pedal bushings appear to have been replaced by a previous owner. There seems to be no problem there.

I intend to get a spring for it tomorrow and give that a try. I also will look for vacumn leaks.

Ed has offered to look at it for me this weekend and I have accepted that offer.

Look forward to driving it again.

I appreciate everyones assistance, thanks

Chip

I don't know crap about FI since I have Webers but I was having similar problems so I rebuilt them. I noticed the butterfly valve on one of them didn't "feel" right. Lots of carb cleaner and scrubbing ensued. Now all is right as rain.

So Chip came with his car today but there was nothing to fix, the high idle problem is gone for now. I gave him a tour of his engine compartment, what to check next time it happens and looked over a couple of other minor issues with the car. Spent the next few hours talking 914's... he's been bitten bad...six weeks in and he has two cars already...nice guy with a nice car....here's his '74 driver

Bitten Bad!! Ya, really bad, especially after visiting ED! I left Ed's and went home and stripped the paint completely from the two front fenders and the first coat, of two coats, on the doors. I also finished a good portion of the front panel behind the bumpers. Did it all with a scraper and paint remover.

After getting a ride in Ed's Black Turbo 914 and his beater/daily driver that shifts like a dream, I think 'addicted' is more like it! I had a feeling on the way home to Connecticut from Bethlehem, PA where I picked up my initial purchase I was in trouble and my MGTD restoration was going to be set back a few more years. In addition my VW Vanagon project just got pushed back till the end of summer after visiting Ed.

Too much fun driving the 914.

Ed was a terrific host, he could inspire anyone into 914 addiction. Thanks for the pleasant afternoon ED.

Chip