88 Fox injection

Greetings,

My 88 Fox is getting fuel to the cold start injector, but not to the regular injectors. the car will run untill the cold start injector cuts out . I'm thinking it's the distribution unit. any ideas, and insights are appreciated.

TIA, rush

"rush ville" wrote

Just a side point, that would not help the matter: did you check that your fuel filter is not clogged?

Harry

check the ground wires on the cold start valve bolts. check ALL of the fuses at the fuse box. I think you have CIS-E and that electronic fuel pressure regulator needs electricity to function. Check that main fuel distributor boot for a massive crack or hole.

Bentley, VOM tool, maybe a fuel pressure tester and have fun. ;-)

later, dave (One out of many daves)

Harry I've had this same problem for almost a year with my '87 Jetta 16V. I have not yet found the problem, but here's what I've done:

Replaced fuel filter, Checked transfer pump replaced main pressure pump after it failed the volume test

Still didn't work.

Sent it to a "shop" that basically failed to fix it, sent it back in pieces.

Started taking things apart at home, cleaned, re-set the air flow disc, cleaned the throttle body, cleaned the fuel distributor, replaced everything carefully.

Didn't ever find anything wrong, but it now starts and idles nicely, but it won't rev unless I let it build up slowly. It will die if I press the pedal normally. At this point I'm suspecting either timing or knock sensor. Might have been knock sensor all along.

By the way, the cold start valve doesn't work over 86 degrees farenheit

- it's not needed. Took me a while to get past that ;)

Not much help, but I'm getting close

- - Rex Burkheimer WM Automotive Fort Worth TX

Harry wrote:

Dave. as I understand it, CIS-E should function purely mechanically. That is, if you were to unplug the electronic fuel control parts it should still run. The electronic portion is an add-on that just fine-tunes the mixture. Is that not correct?

No I think if that Fuel Pressure Regulator, an electronically controlled one, does not get electricity it might cause the fuel injectors not to get enough fuel pressure thereby not allowing the fuel to exit via the injectors. NO GAS!

I am talking about the Fuel Distributor with the rectangular box (FPR), connected with 2 screws, and an electric plug.

later, dave (One out of many daves)

"Rex B" wrote

It is obvious, it is not getting fuel. If you can't find the problem, though this may sound quite trite. as the goal is to find the specific failure, and you say you are getting fuel volume- you may want to hook up a pressure gauge to the fuel line too beside just going by volume - lacking diagnostic equipment - you may want to consider just swapping components from a junk yard from a Fox - as a last resort - may cost 20 or 30 bucks or less - I have seen a number of Foxes at our local yard at times.

Harry

I suspect, perhaps, the diaphragm pressure regulator. If the differential pressure regulator failed it should still run even be drivable.

You can test the pressure of the diaphragm pressure regulator jumping the fuel pump overriding the relay.

Should be around 80 psi at that point. You may want to drop in one of those pull-it-yourselfs and pull a diaphragm pressure regulator out of a Fox - maybe 5 or 10 bucks.

Harry

In other words. it has a pressure limit - if this is faulty it could be sending back to the fuel reservoir at a much lover pressure than it should or worst yet it could be stuck open to send the fuel back, thusly, no system pressure. They system pressure is created by the fuel pump and regulated by this (diaphragm pressure regulator).

Harry