[tadslc]

I've had a thread going on the Yahoo TurboEsprit site but figured everyone needs to share the love. Here's what I'm up against now. Little did I know when I originally posted about poor cold weather running that I'd find this:

Got love previous owners, NOT

I started a post called “Cold Running Problem HCi” but under the current circumstances, I must rename the fun I am having. Thanks to all that tried to help.

After checking out most everything I could with y’alls help I came to the conclusion that something just wasn’t right, nothing associated with the RPM Relay worked. Well obviously the fuel pumps worked but that’s it.

I remembered something the PO owner had told me to be careful leaving the key on because the fuel pumps would continue working. I was even able to do all my cold pressure checks without ever starting the car. Didn’t really think much about that until yesterday. Earlier, somewhere in a post I read that the fuel pumps don’t start working until you start cranking the car but mine did.

Armed with this info, I looked closer at the RPM Relay and was shocked or relieved at what I’ve found. A previous owner in his infinite wisdom to install the MSD CDI box to replace a possibly bad ignition amplifier had wired the RPM Relay totally out of the loop. Fuel pumps not working? No problem I’ll cut the wire to the RPM Relay (87b) and wire it to a wire that previously had gone from the coil to the ignition switch. Another wire, from neg coil, that had previously supplied power when cranking and running to RPM relay to trip the relay found life powering the tach through the MSD.
My car was also missing the Ignition Solenoid, Overboost switch and most of the vacuum lines. Why it even ran amazes me. Brilliant!

Anyway, I’m happy with what I’ve found but a little nervous that once I get this all straightened out that I’ll find the real problem. I’ll keep you informed.

Thanks

 

[jtrealty]

I believe it is a case of the PO (or his mechanic) not understanding how the car is supposed to work properly in the first place so they "improve" it by the kinds of things you are seeing. Once you see this kind of work in one area the entire car becomes suspect. It also becomes a much bigger job than just trying to fix the problem because now you must undo all of the damage caused. Take nothing for granted now and assume everything must be checked and tested.
David Teitelbaum

 

[carbuff]

Take nothing for granted now and assume everything must be checked and tested.

^^^ David got that right!


Years ago, the owner of a Bosch '87 spent all kinds of time and money chasing down drivability problems...ALL BECAUSE THE TWO RPM RELAYS HAD BEEN SWAPPED. A mechanic did it, and forgot to swap 'em back.


Hope the probes on your multmeter are sharp.

 

[tadslc]

I agree 100% David.

I am looking into everything I can and it seems that everything is pretty well stock. That's not to say that there isn't a greater problem lurking when I get what I can see repaired but I think I may get off easier than I deserve, electrically anyway.

Fingers crossed...

I did get a new RPM Relays 1 & 2 before this discovery.

 

[carbuff]

You always have to wonder WHY the wiring was changed in the first place.

 

[tadslc]

Here's what I figured out today.

On a stock Esprit, there are 3 wires that go to the neg coil terminal, wire to distributor, wire for tach and the wire to the RPM Relay.
The PO basically had the MSD unit hooked up correctly but didn't pursue the reason the fuel pumps wouldn't work (at least I hope so, I'm giving him a little benefit of the doubt).

I talked to a tech at MSD today and hopefully got it straightened out. The PO had run both the tach wire and relay wire that was previously on the neg coil terminal to the tach input on the MSD unit. According to the tech, it is very common for the normal tach input on the MSD unit to not be able to supply enough power to run a relay. That's why they offer a tach adapter #8920, to up the power to be able to power the relay. I ordered one today and should know soon enough.

I also started straightening out some of the creative wiring this evening and came across some things that have me stumped.

According to the wiring info from the service notes (section ME, sheet 3C), pin #87 on the RPM Relay goes to the inertia switch then to the Overboost Switch. From there it goes to one of the fuel pump relays, the fuel pump failure module and then onto the fuel pumps.

Problem is, I've traced the wiring and it doesn't go that way at all. The wire from the RPM relay, pin 87b, goes to the overboost switch. The pink/red wire on the overboost switch that should go to the the fuel pump relay goes to an unused relay socket next to the fuel pump fuses and idle up relay control relay. Looked at the wiring and such and it looks like this hasn't been tampered with or moved. This goes against what's in the service notes. What am I missing?

Here's a picture of the unused blue relay socket:

There is also 2 empty fuse holders that have wires to them that's not in any wiring diagram I've seen either. They are above the fuel pump fuses.
Any idea's?

 

[tadslc]

Well, I've just reinstalled the ignition/coil box after having it on my kitchen table for what my wife said was "too long".

Unfortunately I never did really figure out what the extra relay and fuse holder was for.

I definitely have a wiring problem but think I have most everything now matching up with the wiring diagrams.

The most glaring problem was the wiring for the 2 fuel pump relays. It was there, just not in the right positions in the relay? They had somehow wired up the fuel pumps to come on with the key, not to come on when the car cranked.

I think the fuel pumps are now working correctly, starting when you crank the car and staying on for a second after shutting the car off.

I got the car to start and have an irregular idle but it won't rev, the car will just die when I apply any gas.

Any ideas where to start?

My plan starts with double checking the fuel pumps by bypassing the relay and then check the fuel pump failure module.

 

[amanda11270]

They were probably thinking the way a modern FI works where the pumps run when you turn the key to the start position, but then the CIS has nothing to turn the pump off.

I have found in working on my CIS that one thing unplugged or one wire disconnected can often cause odd symptoms. It amazes me what can be disconnected and the car still run, I drove my car for a while until one day it hit me the frequency valve wasn't buzzing. It was a bad connection at one of the relays in the rear trunk or a bad realy, don't remember now. I feel like a better technician now though since I've conquered this car.