TSB 3-16-1 or not?

[ford4fun]

I have a 99 WS 3.8 with about 86k miles. Several months ago the CEL came on and mech said it was MAF sensor. Didn't replace since performance not noticeably impaired. Recently, started having some problems. Before engine reaches normal operating temp, engine will shut off or run really rough. At times it wants to surge or jerk. Once engine reaches operating temp, you can be driving at 60mph and it seems as though the engine cuts off for a split second, you feel a jolt, but the engine immediately returns to normal. Other times it drives fine at op temp. Most of the time now when cold, it generally shuts off once or twice.

Took it in to mech. He went ahead and replaced the MAF although he didn't think it was my primary problem. Sure enough, he was right. The CEL continues to come on, but the only reading he gets has to do with a lean condition (don't know what codes).

Sorry for being longwinded, but I've read through a number of posting and can't quite match up my problem with those listed. Maybe someone can relate this to their experience and offer their advice. Since the problem seems to only occur when the vehicle is cold, there is only limited time for the mech to do the testing, so its been very challenging. The mech is not a Ford dealer.

Any help would be greatly appreciated!!!

[DRW1000]

step 1 Get the actual codes.

A lean condition occurs when air is in the intake that the computer does not "know" about or the proper amount of fuel is not being delivered.

Air enters through the intake and it is the MAF that detects the mass of air. If the MAF is not accurate then one can get lean codes. Since you replaced the MAF one can assume that the MAF is okay (for now anyway).

Air can also enter through leaks in the intake after the MAF.

A common place on the 99s is through the port seals that have loosened due to the deterioration of the rubber on the Isolator bolts due to oil contamination. This problem can be augmented when cold.

A weak fuel pump may also cause less fuel to be delivered which of course the computer sees as a lean condition.

You MAY very well have the problem that calls for the TSB but the codes will help to narrow it down. The codes are P0171/P0174. You also may have something else.

The TSB quite clearly states that the codes are present but no other drivability concerns are present. Your jerking and cutting off at 60mph sounds like drivability concerns imo.

Get the actual codes. (If you live in the US Autozne will read them for free) and that will narrow it down somewhat. Post what you find and one of the folks here will be glad to offer their opinion.

[Windywoes]

Originally Posted by DRW1000

step 1 Get the actual codes.

A lean condition occurs when air is in the intake that the computer does not "know" about or the proper amount of fuel is not being delivered.

Air enters through the intake and it is the MAF that detects the mass of air. If the MAF is not accurate then one can get lean codes. Since you replaced the MAF one can assume that the MAF is okay (for now anyway).

Air can also enter through leaks in the intake after the MAF.

A common place on the 99s is through the port seals that have loosened due to the deterioration of the rubber on th Isolator bolts due to oil contamination. This problem can be aumented when cold.

A weak fuel pump may also cause less fuel to be delivered which of course the computer sees as a lean condition.

You MAY very well have the problem that calls for the TSB but the codes will help to narrow it down. The codes are P0171/P0174. You also may have something else.

The TSB quite clearly states that the codes are present but no other drivability concerns are present. Your jerking and cutting off at 60mph sounds like drivability concerns imo.

Get the actual codes. (If you live in the US Autozne will read them for free) and that will narrow it down somewhat. Post what you find and one of the folks here will be glad to offer their opinion.

Prior to my TSB 03-16-1 work I had the 171/174 codes and replaced the fuel filter. CEL stayed off for about 15,000 miles and engine seemed to run better. Maybe it is a stretch, but replacing the fuel filter is easy (and necessary if it has not been done in a while) so give it some thought.

[yotermanic]

Usually on Windstars with a 3.8 171/174 codes (lean banks 1&2) are from intake o-rings. We see a lot of them in the winter as the cold causes shrinkage. Ford has revised parts.

[DRW1000]

Originally Posted by yotermanic

Usually on Windstars with a 3.8 171/174 codes (lean banks 1&2) are from intake o-rings. We see a lot of them in the winter as the cold causes shrinkage. Ford has revised parts.

I know that the Isolator bolts have been revised (black rubber vs green) but have the port seals been revised as well? I always assumed that they are replaced as a precaution only when doing the isolator bolts and not due to a newer design.