1999 No start issues

[Patmandu]

I hope someone can point me in the right direction to fix a no-start situation with my '99 V8. I was out for a 100 mile drive with a local sports car club a few weeks ago, and the car was running great. I noticed it was a little slow to crank (but started right up) after the first break, and it continued to run perfectly when I parked it for lunch. After about 90 minutes the engine would crank but wouldn't start. There was no check engine light, but I didn't hear the fuel pumps run with the key in the second position. I ended up having the car towed home because I ran the battery down trying to start it. When I got home I pulled a P1101 code from the OBD port by battery. I swapped the two brown relays, but no luck. I thought perhaps the battery was bad, even though it was only two years old, so I got a new one - no change. I can clear the code but it always comes back. I can jump the primary fuel pump relay and get 52lbs of pressure at the fuel rail, so I believe the pumps are OK. I also get 52lbs when cranking the car even though I don't hear the pumps running before I start the car. I know the check engine light bulb is OK because I took it out and it lights when connected to a 12V power source. I pulled one of the spark plugs and it's getting a good spark. I notice I can hear the fuel pump running when I stop cranking the car. I just got new relays today, and no change. It cranks like it wants to start, but it never does. I don't smell gas or anything, and the sparkplug looked perfect. I reset the rollover switch, no luck there either. I have also replaced all the fuses, although none tested bad.

Any thoughts?

[mike_sekinger]

Hi Patrick,

P1101 is primary pump relay or circuit shorted.   Are you sure that your primary pump is good?  When establishing the initial fuel priming, both pumps should run - but if only the secondary is running you will still observe pressure on the rail.  After the priming, the secondary pump stops and is only commanded at higher engine loads.  The pressure will remain for a period after this priming, so if you are cranking immediately, then there will still be pressure in the rail.

What I do not understand is no start despite having apparent fuel and a good spark.    Does the engine not start at all or die after a very short time?

Regards,

Mike S

[Patmandu]

 Hello Mike,

The engine won't start at all. There are a few things that don't make sense - The MIL light doesn't go on, the pumps don't go on when they should, but go on when the engine cranks, and I have spark and fuel pressure. I'm guessing the injectors aren't firing. I can jump the pins in the relay socket to get the main fuel pump to run, and I can see 52lbs of pressure at the rail. I haven't tried jumping the secondary pump yet, but I can try that today. Could the immobilizer cause this? I only see fuel pressure when the engine is cranking or I'm jumping the relay socket, not when the key is in the second position.

[mike_sekinger]

The Immobiliser is killing your spark, so I doubt that is the issue.

The primary pump and injectors are on the same relay.  I hate electrical gremlins.....

Do you have Service Notes section ML15?

[Patmandu]

Mike,

I've been looking at the wiring diagrams in section ML, is that what you're refering to? 

[Patmandu]

Mike - do you still have any V8 ECU's for sale? It would be good to have a spare in case mine is toast.

[mike_sekinger]

Hi Patrick,

I only have one spare, which is itself questionable; I think it has a driver issue.

If you can borrow a unit from someone that would be useful in determining if the ECU is at fault.

Mike

[Patmandu]

Mike - they seem to be impossible to find. As a quick update, the P1101 error is gone with the new fuel pump/injector relay, but it still won't start. All the other symptoms are still there. I took the ECU out and inspected it but didn't see any burnt traces or exploded caps. I sprayed contact cleaner on the pins and connector but no change. I also hooked a jumper cable from the negative battery terminal to the exhaust tip to make sure it has a solid ground, but it didn't help. 

I wish there was a way to look at the voltage from the ECU to the injectors without taking off the plenum, but I guess that's my next step in troubleshooting. I'll replace the coils and plug wires while I'm in there. Is there anything else that shoud be replaced? I thought I read the stock injectors aren't very good, is there an updated part that will work? The car has 43K miles and I'd rather proactively replace stuff than wait for it to break.

[mike_sekinger]

You may wish to reach out to Eric Berg (he is on Facebook) to see if he would be prepared to check your ECU out.  He has helped a number of owners by repairing bad drivers in the ECU and is very competent.

For the injectors there are a few options:

RC Fuel Injection SL2-0240 <br/>Saturated Injector

Bosch - part # 0280156211

Please keep us posted as you progress.

Mike S

 

 

[Bibs]

By chance this just popped up on FB...

[Patmandu]

Thanks for posting this! I was able to buy it and can’t wait to see if it fixes my problems. Unfortunately I’m going on vacation for a few weeks and won’t be able to test it until I get back.

[cweeden]

I've whizzed through this so not sure if its been mentioned or not. Have you checked the rough terrain / crash imobiliser (not sure of the proper name off the top of my head)?

It's a trip switch that you may need to reset located at front of the engine bay behind the drivers head (in the UK).

[mike_sekinger]

10 minutes ago, cweeden said:

I've whizzed through this so not sure if its been mentioned or not. Have you checked the rough terrain / crash imobiliser (not sure of the proper name off the top of my head)?

It's a trip switch that you may need to reset located at front of the engine bay behind the drivers head (in the UK).

The inertia switch/rollover switch checked in the first post

[lotuslover1]

hi

curious what you paid for the ECU,as i still have my spare which i purchased off Mike a few years back as a spare ,in case i ever needed it.

[Patmandu]

I paid $2K for it. All in all I think it was a fair price.

[lotuslover1]

👍

[LotuStuart]

On 08/06/2023 at 11:31, Patmandu said:

I paid $2K for it. All in all I think it was a fair price.

Did this fix the problem?

[Patmandu]

I haven’t been able to install it yet. I won’t be able to try it until the end of the month.

[Patmandu]

As a quick update, I was able to install the new ECU today, and the engine started right up. It hasn't been run in over six weeks, so it was a bit rough at idle but it cleared up and ran smoothly after five or six minutes. I just got back from a short drive and it's as good as new. Now for a good bath (for the car) and I'll enjoy driving it this weekend.

 

Thanks to all for your help and advice!