Jenvey Throttle Bodies

[Craig]

I am having an issue with my Jenvey Throttle bodies on my 2.0 Ford Zetec. The Jenvey Throttle bodies I have are like Weber DCOEs. Last year the screw stripped out of the balancer that balances the front throttle bodies with the rear throttle bodies. A repair was made and the engine ran great.

 

The issue that I am now having is that when the engine is first started The idle is around 800 rpm. After running the engine and the engine temperature is over 200 degrees Farenheit the idle increases to 1600 to 2000 rpm. This make it difficult to shift into first gear from a standing start without turning the engine off sh ifting the transmission into first then starting the engine with the clutch depressed. Driving on course is no problem.

 

Anyone have any suggestions?

 

Thanks in advance.

 

Craig in the USA

[CageyH]

It sounds like either the throttle bodies have not been set up properly, or you have a mapping issue.

If it were me, I would lower the idle when hot to around 850rpm, and take it from there.

[charlie_pank]

Sounds like 2 separate problems to me:

 

1. Your clutch cable needs to be adjusted to stop it dragging. Engine speed shouldn't affect how easy it is to get into gear

 

2. Your idle should settle down once the engine warms up. I presume it hasn't always worked the way it does now. Problem with a coolant sensor? Can you reset the TPS?

[Jason Plato]

using the idle screw, adjust the revs to 800 when hot (not when cold).

[Phil B]

Hello Craig,

 

Have you tried disconnecting the temp sensor to the ECU once the engine is hot? If doing this causes the engine speed to drop back to 800rpm (ish) this could indicate a temp sensor fault.

On my blacktop Zetec and Omex 600 ECU I use the original Ford cylinder head sensor probe, but others use a regular water temp gauge probe. The ECU carries a calibration which it uses to adjust fueling and ignition to enable cold start. If this doesn't drop out when the engine is fully warmed up it would push the idle speed up. Depending on the ECU this may cause an idle speed which is outside the control limits set for the idle spark strategy. In other words the engine isn't running slowly enough for the closed loop control of idle, which is generally on a Zetec 950rpm +/- 200rpm, to be effective.

 

So, first step identify where your engine/coolant temp sensor is located and where you can unplug it from the loom. Start the engine, let it warm up, stop the engine, unplug sensor, restart engine and see how it idles. If has returned to "normal" then probably a sensor failure.

 

Good luck,

Phil B