martyp

I'm working my way through a cold start issue diagnosis and am ready to look at fuel pressure. I have a gauge in hand ready to install and I'm prepping for the actual test. The WSM and local posts indicate jumpering 30-87 on the CE panel after the relay has been removed. On my car (90) the relay is directly behind the LH/EZK computer assembly. I'm not sure I can remove the relay without removing the computers first, let alone jumper a hot system for the pressure test. Hands just too big and clumsy. So I'm looking for alternatives to the jumper method.

I could prolly build up a simple switched jumper and maybe get it installed with a bit of work, but any other ideas are appreciated.

martyp

Went ahead and pulled the EZK and the relay. On my way to RatShak for switched jumper parts.

Bill Ball

No other easy way to do this. The power wire to the fuel pumps comes out of the CE panel at U25. So, you could find a hot source and jump it to there.

StratfordShark

So is arrangement of ECUs and CE panel different for LHD? On RHD cars where CE panel located in left side footwell there is no problem with access to any of the relays? Can someone post a photo? I am intrigued by the difference

dr bob

Marty--

You can pull the vacuum hose at the fuel pressure regulator (right rear, the one on the passenger side under the airbox) and stick a golf tee in the hose. Start the car, let it idle, and read the fuel pressure. It will be the same as with FP relay jumpered and engine off. FP will be higher than what it would normally be at idle with hoses connected, so don't try this while trying to get idle CO set.

John Speake

Be very sure you have the correct pins on the FP relay base when you jumper them. If you get the wrong ones you can damage the LH ECU. It is safer to unplug the LH 35way connector beforehand.

rbrtmchl

Here is a picture.

Bill Ball

When inserting jumper wires into relay sockets, I clearly identify 87 first, insert that end first and then the other end in 30, rather than 30 first. Maybe kinda basic, but you never know.

I have a relay puller - sort like rubber coated pliers with a 90 degree bend - that can reach in there and pull it w/o removing the EZK.

Bill Ball

I did mention that U15 is the output to the fuel pumps. You do have some real fat red wires nearby, like T25 (30 amp radiator fan) or U21 or U15. A jumper wire with small spade connectors on the ends inserted there could do the same thing as pulling the relay.

martyp

Another picture

martyp

Thanks for the idea Bob. I had already fabbed the jumper and completed the test before I came back to the 'list. That'll teach me to be patient!

martyp

I followed your advice John and unplugged the LH before running the test. That was easy to do Thanks for the help.

martyp

Previously you mentioned U25 as the fuel pump output?

I think you are suggesting a jumper between U25 and T25, U21, or U15 - that would certainly be easier than pulling the relay. I hate those things - they feel like they are gonna fall apart, and once replaced they never feel as tight as before removal.

Thanks Bill, always appreciate your help.

martyp

Again, thanks to all for your help. The results are in:

Pressure after initial relay jumper applied: 3.9 bar
Pressure 20 minutes after relay jumper removed: 3.9 bar
Pressure at idle: 3.7 bar

The pressure does increase as throttle is added above idle but consistently settles to the same value at idle.

So it looks like the leak down is OK but the idle result is high. WSM says "approx. 3.3 bar" is expected. Does this indicate a problem, such as a regulator issue? Anything else I should look at here before moving on?

dr bob

Try a vacuum gauge on the hose that's attached to the FPR, and verify that you have somewhere in the 14+ in/hg range there at idle.