1994 F 150 4.9 timing information wanted

Isn't ther a vehicle emission information control decal under the hood, core support area. That has your timing info on it as for checking and adjustment This procedure is for Distributor Ignition systems only. EI low data rate and high data rate systems cannot be adjusted.

4.9L/5.0L/5.8L/7.5L DI Remote Mounted ICM Computer Controlled Dwell (CCD) (System H)

Procedure 1994 4.9 truck

1. Place transmission in PARK or NEUTRAL, A/C and heater in OFF position.
2. Connect an inductive timing light, Rotunda 059-00006 or equivalent.
3. Disconnect the single wire in-line SPOUT connector or remove the shorting bar from the double wire SPOUT connector.
4. Start the engine and allow it to warm up to operating temperature. To set timing correctly, a remote starter should not be used. Use the ignition key only to start the vehicle. Disconnecting the start wire at the starter relay will cause ICM to revert to start mode timing after the vehicle is started. Reconnecting the start wire after the vehicle is running will not correct the timing.
5. With engine at timing rpm if specified, check/adjust initial timing to specification.
6. Reconnect single wire in-line SPOUT connector or reinstall the shorting bar on the double wire SPOUT connector. Check timing advance while varying engine speed to verify distributor is advancing beyond the initial setting. If it is not, refer to Section 2A, Quick Test.
7. Remove test instruments.

I mis-Typed the title, it's a 1993 4.9 F150. Is the 93 and 94 the same procedure?

No there isn't a sticker with this information. Yep, it's the distributor type ignition system. Do you have the actual timing specifications?

Thanks Dave

Base timing on all EEC-IV distributor ignition systems is 10* BTDC.

Make sure that you disconnect the spout connector and not the octane adjustment plug (they look identical) IIRC, the spout circuit is a yellow wire w/green stripe.

Are these connectors located on the distributor?

Also, currently the timing seems to jump a little, kind of like there is a loose timing chain. Just a brief bleep of 5-7 degrees. What would cause this?

thanks again

Dave

It is normal for the timing to jump at idle. It is the ECM changing the timing as it has been programmed based on a set of inputs that in simple terms flip-flops back and forth looking for a value that cannot be found as in the EGO sensor. The ECM wants an ideal number but the sensor(s) cannot/will not provide it. For instance, the ECM may be looking for a value of 0.5vdc. The sensor(s) is such that it flip-flops between 0.4-0.6vdc. This keeps the system constantly tuning itself for optimum efficiency. In some cases, if the ECM has detected a hard fault such as a value that is not changing properly or within a designated range, it will go into limp mode where the timing will only change according to a predetermined failsafe table of parameters. When you pull the SPOUT connector located over near the cruise control unit on the left fender liner it will be rock solid. Your 4.0 does not have a chain. It has timing gears which rarely fail. There are better explainations but, they are going to get much more technical if you are ready for an automotive engineering lesson. Someone here will probably be able to provide more than you ever wanted to know.

The 4.9L six may be one of the most bulletproof engines ever produced even if it's performance is not up to the demands of many drivers. After having several of them over the years, I went to the V8's about 15 years ago when they started raising the interstate speed limits. I find the

5.0L gets both better performance and fuel mileage at the highter highway speeds.

Lugnut

No. They are/have been located in various parts of the engine control harness, though often very near the distributor or ignition module if remote mounted.

Failing stator, failing ignition module, failing PCM, crossfire between ignition wires, distributor cap carbon tracking/damp cap, but if you haven't pulled the spout connector, it's meaningless unless you think it relates to a specific symptom or problem. It's not a loose timing chain since the 4.9 uses gear on gear to drive the camshaft.

My pleasure.

You pretty much hit the nail on the head with your information!! The timing is right on spec with the connector disconnected. It looks like I have a high voltage leak in the distributer as I getting the jump in timing with rouge pulses looking like its a cross fire from another terminal on the cap.

I'll look into it in the morning.

Thanks!!

Dave

aarcuda69062 wrote: