Running rough...code 18

I'm stumped and need some advice.

Took the 91 CV wagon to Tennessee about a month ago. Had new plugs, rotor, cap, wires and TFI module installed before trip. Car got hard to start on a gas stop on the way the TN. Got worse while there. Took it to a Ford garage who diagnosed it as a bad fuel pump. Installed a new pump and filter and said the regulator checked out fine.

Drove great on the way home and around town when I got back. Took the CV to dinner and on the way home, it started to run rough...felt like the engine cut out momentarily. Seemed to idle fine and rev fine in neutral but ran rough under load.

Spoke to a Ford mechanic I know (in Florida) and he suggested the stator was bad. Decided to replace the distributor rather than change the stator (should have done that instead of replacing the TFI module). Installed a new Carquest distributor (new cap, rotor and module), timed it and it still ran poorly. Even in neutral, the engine does not want to rev freely. Under load, the power is very low.

Bought a scanner and got an 11 in KOEO (no problems) and an 11 (no problems) in KOER. Still ran rough...barely idled when cold but smoothed out SOME when warm. Still would cut out under load. Pulled the distributor, reinstalled it, retimed it and ran the codes again. Still got an 11 in KOEO but now got a 12 (idle RPM out of spec) and an 18 (SAW circuit failure) in KOER. I can't find any specifics about the SAW circuit failure, can't find the term in the shop manual, not much through google except some F150 forums call code 18 the code of death.

The car is at a shop now but I don't think they've worked on it since Saturday. Going to check in with them tomorrow.

Any suggestions on what the problem (and possible solution) is?

 

Been retired for 10yrs but I'll offer my .02. Code 18 points to SAW (spark angle wave) or SPOUT (spark output). It looks like you've replaced everything related to it except the wiring. First thing I would ck is everything that has been done already. Just because the parts are new doesn't mean they're good. Recheck the fuel pressure and make sure it's in spec. Should be around 30psi running and 40psi with the fuel pressure regulator vacuum hose removed while running. I would look at the stator next if the pump ck's ok. Going by how you described the problem I would start the car up and disconnect the spout connector (the little plug you remove to set the timing) and see if it runs better. If it runs better I would suspect a bad stator. One other thing to look at is the MAF sensor, the sensor located between the air cleaner and the long plastic tube to the throttle body. Sometimes a small piece of debris or dead leaf will find its way to the sensor and cause false readings to the ECM. Problems like this can be difficult to fix over the web. Without being there I can only give you my best guess. Let us know what you find.

 

Thanks, 60Courior. Don't you love being retired?

The car is at a shop now but I don't think they're doing much. I think they're stumped and won't admit it. I may pick the car up today and bring it back home. I'll have to get a fuel pressure gauge (maybe Advance Auto or O'Reilly's rents them). About the MAF, I have looked for that before and cannot find anything that looks like one. I had another mechanic tell me that my car does not have one. Most of my limited mechanic experience is with 1960's Fords...all the wiring, sensors, etc on the CV make my eyes glaze over!

 

Your car is speed density so it does not have a MAF sensor. What brand TFI module did you install on it? Quality for modules is all over the place on those.

 

I'm going to ditto the TFI module quality. Just because it was replaced doesn't mean it's any good. A number of people have reported all sorts of complaints from various vendors who have consolidated and cheapened the heck out of these modules. I know GM HEI modules are something you never want to swap out with a parts store equivalent as they are all garbage now, I can't imagine the Ford equivalent being much better.

 

You mentioned you thought the place working on it might be stumped as to what's wrong with it. Your car is going on 30yrs old, maybe they don't have a guy old enough to recall the quirks of an older car. Couldn't remember what year they all switched to MAF sensors. Yours would have a MAP sensor (load density system) which is located on the firewall with a 3 wire plug and a vacuum hose to it. They go bad once in a blue moon but I would look at all the other stuff first.

 

Kevin

The TFI module on the car now is the one that was on the Carquest distributor I installed (https://shop.advanceautoparts.com/p...8-P?navigationPath=L1*14923|L2*15034|L3*16062).

 

60Courior

I understand about the age of the car and the age of the techs at the shop. I would be fine with them saying they can't figure it out. I'm getting a little frustrated when they tell me the tech is working on the car in between other jobs and the car has been in the same place in the parking lot since noon on Saturday. I went by the Ford garage today and explained the problem to them. They said they could not work on it...too old. I'm glad the dealer in TN that checked and replaced the fuel pump was able to diagnose and repair that problem.

I'm going to pick it up tomorrow and bring it home. I bought a fuel pressure tester today at O'Reilly's and I'll check the pressure. I'll also pull out the spout connector and see what effect that has.

In the event you guys can't talk me through a fix, I'm checking around for older Ford mechanics that might be able to help.

 

That distributor doesn't have a ton of real positive reviews on the Advance website for what it is worth. I cannot tell what module is on there from the angles they show and the only individual module they sell is an Accel which I have not heard awesome things about.

When I was having ignition issues with my '85 LTD a few years ago I lucked out and bought a new Motorcraft distributor from RockAuto for not much $$ (looked like it had been sitting on a shelf in a warehouse since 1986. I also replaced the TFI with a Motorcraft part and mounted it on the driver's inner fender to keep it cooler. I believe the root cause of my issues was a faulty pickup in the distributor, but it was difficult to recreate the problem since it only occurred after driving for 2+ hours so I just replaced everything.

Typically the TFI module will just overheat and stop doing its job for a while until it cools down and then works fine again for a while. I'm sure they fail in other ways too.

Usually when the MAP sensors go bad on these they wind up causing an overly rich condition. There is a test procedure for them, but I'd have to look it up since I don't know where it is off the top of my head.

 

I owe the shop an apology...they have been working on the car. Got a call today and they had scanned the codes. They got a code 87 (CM scan, I think). They believe the new distributor is bad. I can't find a new Motorcraft distributor anywhere...dealerships don't have it, Green Sales nada, google nothing. I'm looking at buying something besides another Carquest. The shop did not charge me anything for their work. Tried to bring the car home and it seems to run even worse...stalls every minute or so. Got it out of the shop and into an adjacent parking lot and it would not run in drive. Used reverse to get back to the shop.

My plan had been to bring the car home, get a new distributor and install it myself. Plan B is to get the shop to get the distributor and install it. I don't really want to install it in the parking lot with temps in the 30's.

I'll keep you posted.

 

Just for the heck of it, unplug the spout connector and see if it runs any better.

 

I'm not sure I could have done that by myself this evening it was running so badly. I'll try to remember to discuss this with the shop tomorrow...maybe start it myself before they pull it into the building.

They did check the full pressure and said that was correct.

 

The SPOUT connector, that just tells the computer that the computer is in control of the timing, when plugged in. When unplugged, the timing is the base setting only, so you still get the waveform that the computer uses to control the coil. If it was my engine, I would put a new module and Hall Effect sensor in the old dizzy. Yes, it does mean you have to use a hydro press to get the gear and collar off the shaft for removal, but if you want your money back from Advance, that one has to stay intact.

 

This may sound crazy, but is there anybody around you that can rebuild a distributor? I don't mean just throwing a new cap and rotor on it. I mean fully disassemble, replace the bushings, check endplay, etc. The pickup is probably the most critical part and also the biggest pain to replace. I would get the highest quality part you can find. The cheap aftermarket pickups are worth as much as the cheap aftermarket ignition modules. Maybe a place that rebuilds starters and alternators might be able to help you.

https://www.ebay.com/itm/Distributo...3119?_trksid=p2349526.m4383.l4275.c2#viTabs_0

My hunch is that most of the aftermarket rebuilds or new (parts store at least) are going to be a roll of the dice.

Aftermarket drop-ins would be Accel 59210 or MSD 8456 to name a few.

 

60Courior...Went to the shop and started the car this morning. It does run better with the spout pulled. It was running with the spout out and when I put the spout back in the car quit. With the spout pulled it idled better...again, not the way it should but better than with the spout in. The tech is a Chevy guy. He's going to call a Ford friend to come over and look at the car with him.

Kevin...I was thinking about getting the factory distributor rebuilt. I'll have to look if anybody can go that in Richmond. Thanks for the parts suggestions. Checked both places that rebuilt alternators and starters. Neither work on distributors now.