Printable Version of Topic

Posted by: clow Apr 12 2011, 02:28 PM

Hi, I just rebuilt a 1.7 EFI all stock. The car run nice at idle but as soon as I press the throttle it bogs out. If it doesn't bog it has just enough power to move the car. The plugs look fine. Is this a vacuum problem or a fuel problem? Any thought?
I am looking forward to the first drive. The weather if beautiful.


Thanks,
Clow

Posted by: mgphoto Apr 12 2011, 04:48 PM

Sounds like the TPS (throttle positioning switch) needs to be adjusted, also check FI points in the dizzy they may need to be cleaned.
Good luck,
Mike

Posted by: mgphoto Apr 12 2011, 04:51 PM

try this link

http://www.914world.com/bbs2/index.php?showtopic=95583&hl=

Posted by: luskesq Apr 12 2011, 05:07 PM

Although you say the plugs look okay, are all of them firing? Timing could also be an issue with poor power.

keith

Posted by: clow Apr 12 2011, 05:09 PM

Thanks, I tried a spare one and it did the same. I opened up the first one and the contacts are fine.

Posted by: vsg914 Apr 12 2011, 05:33 PM

Valves set wrong, timing way off, or dwell way off. Or, maybe all of the above.

Posted by: vsg914 Apr 12 2011, 05:41 PM

Did you properly adjust it?

Posted by: Spoke Apr 12 2011, 08:04 PM

Does the engine rev up ok?

When you timed it, did you notice the mechanical advance?

With the vacuum lines on the dizzy, did you notice the vacuum advance?

I don't think it would be the FI points on the dizzy. All they do is tell the FI when to fire the injectors.

Are all the cylinders firing? Check by touching the exhaust pipes near the muffler. Best done when the car is first fired up.

Posted by: clow Apr 12 2011, 08:08 PM

Well I am going to go over the whole timing and distributor again. This has been mentioned a couple times. All cylinders are firing. I have been reading about odds and ends to do some I will give them a try.
The push rod tubs started leaking...then oil started dripping and whoosh there was a fire. I had it rolled out in the driveway and it was put out in no time with the extinguisher, no damage. I am going to replace at the seals again just to be on the safe side so it looks like I can't get back to trouble shooting until this weekend.


Thanks

Clow

Posted by: ppetion Apr 12 2011, 09:09 PM

Posted by: rick 918-S Apr 13 2011, 08:36 AM

Oil usually doesn't ignite. It will smoke and stink but flames? Guys run with leaking push rod tubes all the time and sometimes for years with no fire.

I would be checking for fuel leaks near the injectors. That's scary. I would also smell your oil to see if you have fuel in it. Gas in your oil if leaked on the exhaust would flame up.

To your first issue: Check your fuel pressure. Low pressure from a weak pump could allow the engine to idle but starve and stall or barely run with low power. Check the fuel line from the tank to the pump (the suction side) for leaks. Under draw it could be acting like a drinking straw with a hole in it. Check the clamps on the suction side as well.

Check all vacum hoses with a squirt bottle of water. The full length of the hose. Some guys use things like carb or brakes cleaner or starting fluid but it sounds like you already had one fire too many and it's possible your extinguisher is in need of a fill now so a second fire may not be an option.

Be sure the vacum hoses are connected correctly.

Posted by: FourBlades Apr 13 2011, 08:57 AM

Rick,

How do you check the vacuum hoses using a squirt bottle?

Spray water and look for bubbles?

Thanks,

John