Quote:
Originally Posted by cyberpine
Thanks RF,
Sensors back on. I do hear the gas pump or something turning on.
I think I'm reading 15 and 34? I might need to do it again as there might be more codes. All of that and see how it runs with sensors on.
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JC
You are in relatively good shape. You have codes 15 and 34 (unless you have additional codes). In your last video you've started your engine with A+B shorted (note rapidly flashing SES light). This is a limp mode - ECM ignores sensor inputs and works from a fixed set of values. It is not advisable to drive a truck - it is design for emergency operation only. As for the codes we know what they are:
15- coolant sensor or circuit/ low temp indicated
34- manifold absolute pressure (map) sensor signal voltage low
1) Lets clear all those DTC codes as they were artificially induced. This is easily done (engine off) by disconnecting negative Battery terminal for about 30 seconds. ECM will clear its fault memory from these codes until it sees subsequent fault conditions.
2) After clearing ECM fault memory we need to make sure that IAC (Idle air) is correctly reset and knows where it is. The procedure is very simple:
a) Place ECM into diagnostic mode by shorting pins A&B - this will force ECM to command IAC to continuously move into fully close position.
b) Without starting engine, ignition in run position you should be able to hear clicking noise from IAC being jammed into full close position. You can see IAC pentacle fully closing idle air passage in the TB (10 o'clock).
c) Remove the connector (It is 4 wire arranged in box) from the IAC and start engine while monitoring idle speed. Minimum idle speed for a stock engine should be around 450 rpm (can be adjusted).
d) Shut of engine, remove A+B jumper, re-connect IAC connector. Restart engine - idle should be around 600-650 RPM. Provided that base timing is correctly set and there are no vacuum leaks.
3) Take a look at the base of TB - there should be a (black) gasket between it and intake. I have bad feeling that it is a used one and it's leaking as I doubt that 'mechanic' installed a new one when he installed F-body TB on. It is worth replacing just to make sure. While looking at TB write down its OE part number - it is stamped on passenger side vertical ledge. You can see it in this photo (17093030):
from this part number we'll be able to determine which base gasket we need to get.
3) You'll need a timing light and distributor wrench to adjust base timing.
Without this wrench getting to distributor clamping bolt in the back of the engine is real PITA. It is also possible that your 'mechanic' did not tightened and distributor can be easily turned. Check it out.
I'll have to get a timing light - you must have friends that are gear heads?? Borrow, beg or rent one for now. I'll make no further comments about having no tools - everyone's situation is different.
If you are able to secure timing light and twist distributor (aka dizzy) setting timing is easy. You'll have to locate EST connector - it is a single wire connector (usually tan/black or brown/white wire) in the harness near Power brake booster.
This connector by-passes the electronic spark timing controlled by ECM and allows the initial timing to be adjusted by rotating the distributor. Use the following procedure (become familiar with entire procedure before beginning):
The ignition timing marks are located on the engine's front cover. A big notch slot on the balancer indicates engine is at (TDC) Top Dead Center. Adjust ignition timing as follows: You truck is specified at 0 TDC base timing
<> Connect a timing light to the number one (1) spark plug wire - it is closest to the front on drivers side. Connect the timing light power lead to a 12 volt power source - Battery terminal.
<> Start engine and allow to warm to operating temperature. Bring engine to idle (650-800 Rpm).
<> Disconnect EST connector - idle speed will drop down (it is normal)
<> Point timing light at the balancer while rotating (slowly) distributor to set mechanical timing. Look for slot on balancer to line-up against biggest notch on the timing tab. It is 0 degrees
<> Tighten distributor clamp to hold in position when initial timing is obtained.
<> Recheck timing.
<> shut off engine and reconnect EST connector. You'll have to disconnect battery for about 30 seconds again as DTC code 42 will be set by ECM - this is normal. After clearing ECM re-start engine. It should idle at about 650 RPM and if you check timing it will be bouncing between 18 and 22 degrees as ECM will be providing continuous timing control.
Alright - can handle this???? Questions??? No need to be afraid. BTW your videos are superb.
//RF