zetec hesitation

[debushau]

I have a Zetec-engined Caterham 7 (US-spec with 2.0L). The last few times I have taken it out, it has had this unusual drop-off of power. Typically I'm driving away and for a split second the rev needle goes to zero and I have no power, then the power just comes back. On one occasion I was in a parking lot and it did it's conk-out routine and I had to turn the engine over a few times to get it started.

 

I have not had a chance to get the codes but I was inclined to think it might be fuel supply related. I previously had a cut-out condition that I traced to a bad ground.

 

Any ideas on what this could be?

 

Edited by - debushau on 9 Sep 2002 23:26:02

[I.Mupferit]

If the rev counter suddenly drops to zero first, it sounds more like an electrical fault to me rather than fuel related.

 

Brent

[Blatman]

I have an almost identical issue with my injected Vx lump.

Checking the earths is a good place to start, along with the condition of the connections on the alternator.

My suspicions have turned to an injector failing. As the injectors on my car are batched (I think), they all fire twice every 4 revolutions, or so I'm led to believe. One may have developed a "high resistance" type problem, and is drawing all the current from the other three, momentarilly causing the engine to stop dead.......It's VERY disconcerting. Trouble is, I don't posses a laptop computer, or a (DTA ECU) comms cable to be able to interrogate the ECU. My plan is to get it to a rolling road in the near future, for a run up and a look see at what's going on. I suggest you do the same.............

[ECR]

It sounds like an electrical fault to me. Try taking a power supply directly from the battery to the live terminal on your ignition switch. If the fault dissapears then electrical it is.

 

I always check alternator connections with this type of problem.

 

Good luck

[debushau]

I will take another look at the earth - there may be a better place to ground the engine that the spots I have chosen. Or perhaps a large diameter than the 4 gauge wire I am using. I just have a stock Ford ECU but I do have a code reader - that may tell me a thing or two if I can put the two together.

 

I thought it might not be electrical because the starter turned over during the fail condition but the engine wasn't firing.

 

Shane

[Peter Carmichael]

It is also worth cleaning up the HT leads and spark plug insulators and checking plug gaps to make sure that RF interference is not confusing the ECU. There should be some RF suppression in the ignition system either in terms of resistive plugs or leads.

[metal mickey]

Just had similar problem with my car (2ltr Zetec). Engine running fine then engine cut as if rev limiter cutting in, turned out to be faulty alternator connection.

Mike.

[debushau]

I rerouted the secondary grounding strap and I thought that was doing the trick until the car was idling one afternoon and then cut out again. I noticed that when I turned the car off and tried to crank it again I was getting no computer "beep". Tried turning it on and off again and after a while I got the "beep" back and the car fired up. When I was originally finishing off the car, I had lots of problems getting the computer to switch on - although the harness seems well screwed into the ECU (Ford) it seemed not to be tight enough. At the time I was convinced it was a duff ECU.

 

After so many attempts at tightening the thing up I think the brass screw may be losing some of its thread. The location of the harness is right under the plastic manifold so it's a pain to get at. Anyway, I think this may be the cause of the problem.