Rough when cold, TFI? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Bass Crazy · 09-11-2002, 15:48

Hey fellas.

My EA MPI has developed a problem overnight. On a cold start, she will run rough. It sounds like she is missing, and can barely hold idle. At higher rpm, there is still a miss. No abnormal smoke from zorst.

Once it reaches operating temp, within a matter of seconds, it will change note and begin running perfectly. This happens on both LPG and ULP.

I have checked all leads, plugs, Cap & rotor, Timing, ECU self test... no problems.

Once the car is warm, there is no power loss at all, runs perfect.

I doubt it's sensor related because it runs the same on LPG. I have a spare ECU and I might put that in to see if there are changes.

Could the TFI be causing this problem? Any other Ideas?

Thanks guys.

Tickford6 · 09-11-2002, 19:08

It's not a bad temp sensor is it? When the car is cold, there is more fuel going in to stop it stalling, so if it doesn't know the car is cold it will not put more fuel in.
TFI functionality shouldn't be so temperature dependant I don;t think.

My 2 cents. Good luck with it Bass.

Bass Crazy · 09-11-2002, 20:22

Howz it going dude.

I guess the temp sensor would be something to concider, however, I ruled it out because the car has the same problem with LPG. The LPG system has no connection to any sensors, besides the ISC. Do you know if the temp sensor is used by the ECU for timing settings?

My Brain Hurts :(

Tickford6 · 09-11-2002, 21:53

Quote:

Originally posted by Bass Crazy
The LPG system has no connection to any sensors, besides the ISC. Do you know if the temp sensor is used by the ECU for timing settings?

In high tech cars, both fuel and spark are influenced by the temp sensor, but in these aussie cars, I think it is just a fuel compensation map. That's what I have been told by a guy at Powerchip, in which case you may be right about it not being a temp sensor.
Is there any mixture control on the LPG for cold starts?

Bass Crazy · 09-12-2002, 01:30

Believe it or not. NO.
My gas system is dead simple. It has a 3 sec primeer which comes directly from the fuel pump relay, and is then switched on by the pump relay.
It has no sensors, its either on or off. I was quite surprised at how basic the design was, however, I get around 500-550km(freeway) LPG, so I'll leave it alone.

I have just confirmed that it is a problem only on a very cold start. It runs rough till about 60 deg (almost operating temp).

I disconnected the temp sensor completely, and all that achieved was an incrreased idle speed, but no difference in the miss.

I think I'll change the TFI tomorow.
How much are these things worth?

My plan of attack to change it is to loosen the dizzy bolt, and rotate the dizzy so that I can undo the screws. Replace the thing, and put dizzy back where it was, and then do engine timing again.
Sound OK?

Thanks again.

Tickford6 · 09-12-2002, 19:42

Not a bad plan of attack Bass.
do you have an EF/EL manifold at all?
I have heard (happened to meafter 80,000 ks) that dizzy shafts seize and TFI modules go in ELs because of the heat that the inlet manifold can trap.
Try and give the dizzy a spin by hand and if it grates anywhere, that might help your problem. The warming up of the block may cause it to spin more freely, so better idle, but it's still a bit of a long shot. Even so, while you're at it, give it a go.
If you have the EF manifold, good luck. It is a bitc# to get in there. Might have better luck removing dizzy from underneath car.

Oh, I think it was about $300 +/- $50 for a new Ford dizzy and TFI module.

Have a god weekend bro,

Jase_ELXR8 · 09-13-2002, 02:46

Check all your gaskets and vacuum line you could have one leaking when cold...

Bass Crazy · 09-14-2002, 01:22

Hey guys.

Yesterday I removed the dizzy and put on a new TFI module($60, lifetime warranty). Only took about 20 mins to get the thing out even with the EF manifold. I started the car and the problem seemed to be fixed, well at least thats what I thought.

I started her this morning when it was real cold, and she was running rough again, not as bad, but still rough.

The dizzy seemed fine. I spoke to two other mechanics about the problem yesterday, and showed them the dizzy, the only suggestion they had was TFI.

On Thursday night(before the TFI replacement) the car refused to run properly even after warming up. After idling for 10 mins, the exhaust system was glowing RED from the CAT to about 1/2 down the car... Very Weird... but sounds like a timing problem to me.

Every mechanic I have spoken to cant help me out, and it's starting to annoy me.

Thanks for the help guys.

Thanatos · 09-14-2002, 02:38

Quote:

After idling for 10 mins, the exhaust system was glowing RED from the CAT to about 1/2 down the car... Very Weird... but sounds like a timing problem to me.

I had this exact same problem when I'd just put the newly rebuilt motor in and it was just the timing being WAAAAYYYY to far retarded...

Dave

Tickford6 · 09-22-2002, 17:02

you know those pics where the exhaust is glowing? that's what happens when you run the engine at almost 0 advance. Most of the combustion and expansion occurs in the exhaust system, not the cylinder chamber.
I also think that this sounds like a bad timing issue .

Good luck