VWDiesel.net The IDI, TDI, and mTDI source.

General Information => Troubleshooting => Topic started by: ein bora on December 24, 2009, 01:20:48 pm

Title: No rpm's past idle/Help needed!!
Post by: ein bora on December 24, 2009, 01:20:48 pm
The other day I started to have problems with my 94 IDI. The car started surging while driving. We had a bit of a cold snap so my first through was cold weather fuel issues. I always keep a bottle of conditioner in the trunk, so I added it - let it idle for a awhile and drove off but it was still doing it. I managed to get home and still thinking it was weather related, I changed the fuel filter just to be safe but still to no avail. Then I made a bit of a portable garage with a plastic tarp and put my propane heater in it. I let it heat for more than enough time but still it wasn't running right. Next I bypassed the fuel filter and fuel lines by feeding the pump directly off of a bottle filled with diesel - and it's still doing it. It wants to rev and runs smooth at idle, but it's like something is holding it back - like it's not getting enough fuel.
It's getting air okay so I'm thinking it possibly maybe the pump. Any thought's or suggestions before I take the pump in for repair?

Any help much appreciated. Thanks.
Title: Re: No rpm's past idle/Help needed!!
Post by: burn_your_money on December 25, 2009, 06:21:46 am
Check your timing and make sure everything is proper. It could be the crank pulley. Also, check all the bolts that hold the pump to the bracket. When they are loose the car often surges
Title: Re: No rpm's past idle/Help needed!!
Post by: ein bora on December 26, 2009, 12:21:08 pm
Quote from: burn_your_money on December 25, 2009, 06:21:46 am
Check your timing and make sure everything is proper. It could be the crank pulley. Also, check all the bolts that hold the pump to the bracket. When they are loose the car often surges

Thanks for the help - I've checked the timing and all appears proper. The bolts are tight and the crank pulley's running straight. The motor idles fine and when you depress the accelerator she's good for about a quarter throttle, the rpm's rise nicely. Once you go passed the quarter - she starts to run rough and surges. I'm stumped - may have to take it in.
Any additional thoughts. Thanks.
Title: Re: No rpm's past idle/Help needed!!
Post by: burn_your_money on December 26, 2009, 05:23:09 pm
1.9 AAZ pumps have a tendency of eating the cam plate in the pump. This causes metal to get into the advance mechanism and jam it up. To test this you would need a pulse adapter or remove to pump and remove both advance covers and see if you can move the advance piston.

Any air in the lines? Try running it off a Jerry Can to see if it still does it.
Title: Re: No rpm's past idle/Help needed!!
Post by: ein bora on December 27, 2009, 10:20:49 am
Quote from: burn_your_money on December 26, 2009, 05:23:09 pm
1.9 AAZ pumps have a tendency of eating the cam plate in the pump. This causes metal to get into the advance mechanism and jam it up. To test this you would need a pulse adapter or remove to pump and remove both advance covers and see if you can move the advance piston.

Any air in the lines? Try running it off a Jerry Can to see if it still does it.

Did the jerry can thing which leaves believing it's pump related. I think I'll send it to Giles at Performance Diesel Injection for a performance make over.  Thanks for the help.