Another non start 3.2 carrera

[HSimmo22]

Hi I am new to the site and much in need. I have read most previous posts and copious information on non- start 3.2 carrera. My story basically started a few weeks ago, the car was going well had slight loss of power on motorway then would not start, I changed DME relay and fuel pump fuse, the fuse appeared blown but I did not properly check, the car started drove for 20 minutes and then started to run rough and stopped, would fire up but was very rough. Then moved into non- start mode. Since then I have changed fuel pump, ignition leads, plugs, rotor arm, distributor cap, coil, reference and speed sensor. I did not mind this as it was all on my to do list, I thought I might have caught the problem by this but to no avail. I have checked the CHT sensor and have the correct ohms reading with it. Fuel is getting to the rail but I am not able to check the pressure, occasionally it sounds like it might fire, but nothing much. I am getting a spark but it does not seem like the strongest. I do not have a strong smell of petrol. I am not sure where to go next. I was thinking about sending DME unit away for a check, I was also wondering if the DME relay I have replaced is perhaps not working, I had it in the glove compartment for 5 years, I was toying with buying a fuel pressure measurement kit and I was also considering getting it trailed to a specialist to get the timing checked etc. Any potential DIY advice or help would be much appreciated.

Many thanks

Henry

[Chuck.H]

Have you checked your DME for cracked solder joints? Do a search on this, very common on the 3.2's...

Also, when you noticed the slight loss of power on the highway, did you notice the tach fluxuating? If this happens it points to the speed/ref sensors - think about it, just a small miss doesn't drop the engine speed very much, but if the speed sensor drops out the DME thinks the engine is revving different and it shows in the tach. Happened to me at about the 300k mark.

Chuck.H
'89 TurboLookTarga, 338k miles

[HSimmo22]

Thanks Chuck, I was thinking of sending the DME to get checked for this, I have already changed sensors and I thought would fix things. I will do a search say you suggest.

[wnsgc]

Henry,

Check out my thread on a stalling 3.2:

3.2 Engine Stalling - Stumped

This may give you some other areas to consider.
Good luck,
Scott

[kidrock]

Henry,

The DME itself, while certainly could be the source of your non-start issue, is usually the last component that is checked for a non-start issue.

You say that you cannot smell fuel. I would "introduce" fuel into the system by spraying some starting fluid into the intake. If it starts, then your car is starved for fuel and your next step is to figure out why.

You say that your spark is weak. You need to pull a plug and ground it somewhere near the engine to really determine your spark. If you are not pulling down a strong blue spark, your coil may be at issue.

You also state that you have replaced both reference sensors (along with a bunch of other items), and state that your CHT sensor ohm'ed correctly. Is your CHT sensor the 1-wire type? If so, this could be your issue. Whether you have the 1-wire or 2-wire, disconnect the CHT sensor connector and bend a paper clip to jump the female end of the connector. At this point I'm just guessing, but it only takes 2 minutes and costs you nothing.

Good luck and get back to us with your results.

[dshepp806]

Make sure that fuel filter is a fresh one....Kidrock's suggestion is a good one for ruling out the CHT sensor....

BEST!

Doyle

[HSimmo22]

Many thanks guys, this is very helpful. The car started tonight and ran very rough, the tachometer seems to work ok was indicating about 1000 and not bouncing up or down. The CHT sensor is the one wire type, it is reading 2.7 ohms at normal room temp. I am thinking fuel problem, it does seem starved of fuel, I will try all of the above at the weekend and get back to you.

Really appreciate your support Scott, I do hope you have solved your problem and I am inspired by your efforts and taking the time to post me the details.

Thanks

Henry

[Joe6pack]

FWIW, I had a similar problem. I was backing out of my driveway and as I backed over the valley gutter, the car shut off. It wouldn't restart. I fooled with it for a couple of weeks and never could get it to fire. I checked the coil for spark and it seemed to have a little and sometimes it wanted to fire, but wouldn't. To make a long story short, it was a cracked solder joint in the DME. It was the pin that told the coil to fire (don't remember which one it is now). I found the answer on a 944 site - might have even been here on Pelican. It's worth a shot.

[HSimmo22]

Good news guys, as per Kidrock suggestion changed fuel filter after checking fuel pressure and delivery and checked new fuel pump install, fired up and running very well, in fact managed the local hill climb on Sunday and was fastest in class. Thanks so much for all your help.

Henry

[kidrock]

Henry, that's great news. A cheap, easy fix is always the best kind. I'd love to take a bow for the diagnosis....but it was actually Doyle (dshepp806) that recommended the fuel filter. Props to Doyle, again!!!!

[HSimmo22]

Sorry Doyle, thank you for advice. I have been on holiday and just managed to check the site tonight. Really appreciate your help.

Henry