I have searched and searched all the hot start issues and still coming up with nothing so maybe yall have an idea I haven't had. Car has a hard time hot starting, has a new high torque starter, has starter relay mod, turns over fine not a cranking issue. If you turn off car and try to restart it right away it still doesn't start up easy, so it shouldn't be a fuel issue -new aftermarket fuel pressure regulators with gauges, not a fuel pressure problem I have checked and watched fuel pressure gauges before cranking and while cranking -both new crank sensors -maf's have both been adjusted to factory specs -new coils -new plugs -flywheel not rattling -timing belt is about 6 years old and has about 1800 miles on it. When trying to hot start the exhaust does pop loudly sometimes and it does stumble but doesnt start, if you try hard enough it will always start but it takes alot, leading me to believe it's something to do with timing. The flywheel isn't making any rattling but I may regrease just to rule that out, please help this car is going to be the death of me. Car also does have a slight misfire about 6k rpms, I'm not sure if it is related or a seperate issue.
Check the wiring to the crank sensors if you've not done it.. Loom side behind the rubber boots. At least you can discount that then..Also do the sensors have the right clearance to the trigger wheel? 0.3 to 0.9 mm. I will say I had a light on the dash too when I had a very similar issue. Crank sensor wiring was partially broken on one sensor.. Would play up when hot and hard to start with backfire.
I feel your pain and I will be watching this thread closely. I've been chasing the hot start issue since I bought my car. I thought it was the flywheel grease I repacked it and still have the same hot start issue. Engine sounds like it has a thrown rod when you're trying to start it it's absolutely horrible, but only when really hot. Then it was suggested that pressure in the fuel tank could be causing it and I did have a massive amount of pressure building up in the tank so I started leaving my gas tank lid loose but even still on extremely extremely hot days I have the hot start issue. And down here in Florida that's pretty much all summer. To summarize I have repacked the flywheel, new plugs, inspected and ohmed out plug wires, new fprs and previous owner fitted the starter relay. I am going to check the clearance on the crank sensors, check for oil and maybe replace just on principle.
+1 Oil contamination of the plug and sensor cracked boots/wiring are known problems. The left bank crank sensor is linked to the tachometer display, so that may be a clue which sensor is playing up (with your 6k problem). Someone posted a photo of the wiring damage on his car, but I can't find it. Anyway, look for torn boots, oil contamination, etc. Note that sometimes the damage is 3 or 4 inches from the connectors.... Sometimes on the ECU side of the connector. Image Unavailable, Please Login
Excellent photo. BTW, someone suggested checking the clearance of those sensors you could certainly shim them out but there's no way to get them closer if need be? What do folks do? Also what is the current part number for aftermarket sensors?
Folks are fitting Kia crank sensors with great success https://www.ebay.com/itm/285061789193 P/N 0K2A6-18-891
First thing. Put a fuel gauge on it. Make sure you are maintaining fuel pressure for at least 1 hour when hot. Report back.
As I stated in my post I have aftermarket fuel pressure regulators with gauges and fuel pressure is fine and not the issue takes at least and hour to drop fuel pressure and fuel pressure comes right up as soon as its cranked but still doesn't start not a fuel pressure issue
I ordered the flywheel socket so going to try repacking as a hail mary but I dont think that is gonna do it, I'm here in Florida too so I definitely know about this heat, I did replace my crank sensors already but I am going to check clearance, I doubt that's it but at this point I'll try anything haha
For my 1991 UK spec 348 TB, I just bought the two push buttons (picture), connected them to existing plugs at the ECU-s, and the code reading works (already had the CEL bulbs in the instrument cluster). Any momentary push switches would also do. Do you have unconnected 3-pin plugs at each of the ECU-s? Image Unavailable, Please Login
What pressure have you set them at? Most 348-s run at 3.0 Bar and, according to what I have read, only some US spec 348 Spiders (or TS-s ?) run at 3.8 Bar. What are the Bosch numbers of your original FPR-s?
Here are some shots of a damaged crank sensor insulation thanks to @Pepsi10 https://www.ferrarichat.com/forum/posts/148741439/
Mine is a Euro car. I retro fitted the test buttons and bulbs in the dash....Have a look here. Scroll down the page. showthread.php
I have a 93 euro spec car they are set at 3.8 bar, my origional fpr's were not leaking before I replaced them and this issue was there before they were replaced
Its a 1991....here is the part diagram...Number 2 and 3 is what you need. You may want to make the looms at the price... https://www.ferrariparts.co.uk/Diagram/Ferrari/348-tb-ts/007A-Air-Injection-Ignition-Motronic-27
