Thank you Steve, Had a few questions: What is the fuel pressure supposed to be at the fuel distributor? What is the Ideal vacuum in each manifold?
Ps = 5.4 +/- 0.15 bar See page D77 of the TR WSM. Disclaimer -- IME, these common vacuum gauges are not that accurate. I noticed (in the video you sent) that you are using two different gauges. As I've posted before, I have two identical gauges from the same manufacturer, and they differ by about 1~1.5 in. Hg when measuring the same intake manifold -- so better to use one gauge to measure each manifold as a final check unless you know the two gauges measure exactly identically or have some correction factor for when they measure the same thing. Depends on your elevation above sea level (i.e., what the absolute atmospheric pressure is): Here at ~800 ft above sea level, my gauges are in the 15~17 in. Hg range at warm idle (but don't know which of my gauges is more accurate). When I lived at ~5300 ft above sea level, my gauges measured in the 12~14 in. Hg range at warm idle (IIRC).
I agree about the gages but i did switch them back and forth on the manifolds and they were repeatable. I am going to replace the 2 relays and check voltage to the fuel pumps through the circuit. Then recheck the fuel pressure at both of the fuel distributors. Once that check is done I am going to take the car to a local ferrari mechanic and have them reset the mixture and idle settings from scratch using the proper equipment. I am pretty sure all of these problems are improper settings and adjustments
Wow! This is typical. Came out this afternoon to put the new relays in. When I put them in it blew both of the fuses. I replace the fuses and switch the relays with original relays from other ones and blew both fuses. WHATS GOING ON? I pulled the face of the panel off and there’s no burn marks anywhere. What now
I use a single gauge "T"d to both manifolds. Pinch one hose read it then pinch the other hose. Easier, cheaper, faster and more accurate.
it blew both fuses at the same time when you put 1 relays in or it blew only each fuse for each relais?
I initially had one original relay in place and when I installed the new relay it blew both fuses. Did I replace the fuses tried using the original relays and every time I would put them in they would blow the corresponding fuse
I tried pulling the tackometric relay and upon installing the fuel pump relays they still blew fuses. I also jumped each fuel pump and the fuel pumps came on
You are using the wrong relays. The relays for the fuel pumps on a US TR should be the ...101 type (with an 87 terminal and an 87a terminal). Unfortunately, the US TR OMs have a carry-over misprint from the TR WSM and wrongly show the ...113 relay (which has two 87 terminals). Early euro TR do use the ...113 relay for the fuel pumps, but US TR do not. The reason the fuses blow when you plug in the ...113 relays on a US TR is that the two 87 terminals of the ...113 relay are always connected together, and this connects the always +12V signal on the 87 terminal of the US female relay socket to the always ground signal on the 87a terminal of the US female relay socket = the fuse instantly blows.
This link will get you a copy of the later US TR wiring diagram book 509/88: https://www.dropbox.com/s/gne5xw608ba818b/509_88%20US%20TR%20Wiring%20Diagram%20Book.PDF?dl=0 which (correctly) shows that the fuel pump relays should be the ...101 type. There are some minor differences from an early US TR (e.g., the odometer not being in the center console), but, for the injection system and fuel pumps, Fig 3 should be the same.
the 87 goes to the fuel pump and the 87a is ground. this F did that the pumps when ignition off never will run because then both connection of the pump have ground
No, 30 goes to the fuel pump, 87 is always +12V, and 87a is always ground: When the fuel pump relay is not energized, 30 connected to 87a = both terminals of the fuel pump are ground as you indicated. When the fuel pump relay is energized, 30 connected to 87 (or if the jumper wire is used in the relay socket to connect 30 to 87) = fuel pump runs.
yes sure steve, you are right ! ! ! normaly 30 is plus input and 87 plus output, but F did it otherwise. sorry, too long not working on a testarossa. since 1 day back in germany have to learn new after 5 month thailand
The saga continues! After getting the right relaysIn for the fuel pumps I ran a few more diagnostics and came to the conclusion that the fuel mixture was dramatically off on the driver side. I removed the throttle linkage so the left hand could operate by itself and started to tweak the fuel or mixture a quarter turn at a time. After about a revolution and a half it started to take affect and after a little bit more it started to idle out like the other side. The vacuum gauges equaled and I started to follow The procedure for setting the idle on both sides. Got everything back together and it was running great check it out for a test drive and 15 minutes into the drive the left Bank shut down. I was able to drive it back to my house check the fuses and relays (The driver side relay was unusually warm.) Turns out the fuel pump died. I pulled the car into my shop and onto the lift and the fuel pump was extremely hot. I tried hotwiring the pump and it did nothing. This is the same pump that I switched out before I started working on this car. What’s up?? On a sidenote, has anybody tried these pumps?https://treperformance.com/i-7546910-ferrari-testarossa-oem-replacement-fuel-pump-1986-1988.html
A bit odd they say "...at 43 psi" for a TR, but the graph indicates it would be OK (as the TR spec is around 120L/hour minimum at about 80 psi). One point is that that style pump is for a later TR with the replaceable check valve and a banjo fitting on the output (like Bosch 69532). If you have the early CIS style pump (like Bosch 69523) with the non-replaceable check valve, you'd need some serious plumbing changes. Search Amazon using "Bosch 69523" AND "Bosch 69532" to see the two different styles, and buy whatever matches what you have on the car now to avoid any extra plumbing work. PS 1 and 1/2 turns on the mixture screw is a HUGE change, but glad that you are getting closer to good running.
Thanks so much for the help Steve. Do you have any idea why the pump would fail? I think I’m going to replace the pair this time. It seems to me while jumping the relay testing the fuel pump, there was very little resistance in the bottom female slot for the relay. I think I might pull the board out and clean all the terminals and crimp them down a little bit. Thoughts?
Not really. These aren't high-end items anymore so maybe just cheap third-world quality. One thought is that the strainers in your fuel tanks have probably come apart/disintegrated (mine had) so that can allow more junk to reach (and foul/jam) the roller pump head. That's a good idea, and it's very important to have good, tight fits between female terminals on the PCB and the male tabs on the relays -- the "normal" operating current of the CIS fuel pump is so high (~10A) that even a very small resistance (like 0.050 Ohms) at those connections results in a huge amount of I^2*R heating that will cook the relay and/or the PCB terminal/trace (even though that 0.050 Ohm resistance, if present, will have virtually no effect on the fuel pump operation).
I think after replacing the old fuel pump he has to turn this mixture screw again those 1,5 turns back but good jason that you come closer to get the car run
The CIS fuel pump runs at constant voltage (and near constant RPM). The pressure regulator (125136) "leaks" fuel from the output side of the pump back to the tank to keep the output fuel pressure at the desired value.
Well, no changes as a result of plugging the vacuum line into the ignition ECU. I balanced both manifolds mixture and reset both idles. My next experiment will be disconnecting the O2 sensors and seeing if that changes anything. I will disconnect the throttle position sensor and try that as well. If those dont work, I will try switching the fuel pressure regulator.
