88 Esprit No-Start - No Spark

[Oznog]

I recently acquired a beautiful 188 Esprit Turbo 40th Anniversary Edition. Car was running great. Was at Road Atlanta last weekend to pick it up and it ran fine around the infield roads on Friday evening. Ran it around the infield roads again Saturday morning for a few minutes to get comfortable with that car. Ran fine, but did stumble a couple of times briefly climbing up the hill to go back into the pro pits. I sat and idled it for a bout 10 minutes or so and drove around the paddock without issues. Then I went out on track for a couple of parade laps, just for fun. Ran like a charm the first lap, but coming up the hill through the esses it stumbled again. Then it just dies going into 10a. It restarted and I tried to drive it up to 10B to get back into the pro pits but it died before I crested the hill and wouldn't restart. Came back in on a flatbed tow. :-( 

I trailered it home to Arizona and started diagnosing in my shop. What I've narrowed it down to is that I've got no spark. Any bright ideas on common issues or what to check? I've already tested every fuse and relay. The way it failed is a little weird. I assumed fuel problem based on the way it sputtered, then died, then restarted for a moment. But the fuel system appears to be working fine. The entire fuel system was recently overhauled including rebuilt fuel distributor and warmup regulator, and new pumps and filter. 

I'm new to the Esprit and at the beginning of a VERY steep learning curve, so any ideas or suggestions would be much appreciated. For now... back to reading Service Notes and looking for clues....

 

Edited October 27, 2023 by Oznog
Updated diagnostic info

[Escape]

Welcome to TLF Eric! That's a lovely car, too bad she's acting up. Probably just wants some attention from her new owner. 😉

Have you checked anything on the ignition side? You're looking for something that will affect all 4 cylinders, so spark plugs and leads are unlikely. The ignition system is no different than similar distributor

- starting with the easiest, are all connections to the coil and distributor good?
- do you have 12V at the coil with ignition on?
- is the coil firing (put a spark plug in the main lead and ground it, or use a timing strobe on the main lead)?
- there is an electronic module (AB14) acting as an amplifier between the distributor and the coil. They are know to fail, only test I know of is to substitute with a known good one. They can be repaired, luckily. Do check the wiring to the AB14 as well of course.

Do keep us posted, there is a huge amount of knowledge and skill on here and most if not all are very happy to share to help those unfortunate with problems. We all want see as many Lotus up and running as possible. 😉

Filip

 

[jonwat]

Beautiful looking car, I used to own number 4 of 40 in pearl white just like it here in the UK. To add to Filip's suggestions to look at is does it have an immobiliser that's acting up? Definitely sounds like an ignition problem though.

Good luck & welcome to the world of Lotus motoring. 

Edited October 28, 2023 by jonwat

[CarBuff]

Common spark issues at this age of the cars: you have Bosch CIS injection.

 

1. Ignition Amplifier, that black rectangle on the bottom of the coil box (mentioned above).  Inside the box is a GM part number module, look up here to get the exact number (or bring yours to the auto parts store). Make sure you reconnect the ground (earth) wire on the engine side of the engine bay wall...

2. Ignition coil is NG or weak. The specs are in the Service Notes. I got one at a NAPA.

3. Broken wire INSIDE the distributor that provides a signal to tell the car that the engine is turning over. I've seen the 2-prong plug going to the distributor break, too.

[Oznog]

Thanks for the feedback folks!

I did confirm 12v at the coil. Will do further testing this evening to see if I can track it down. Thanks for the  info on the amplifier... I wasn't sure what this was. Good to know it's a GM pert than I can hopefully source locally. I'll see if I can get a new coil while I'm it it. I know I can get these from r.d. enterprises, but the more I can source locally, the better I like it. 

Because of the way it failed I really though it was going to turn out to be a fuel issue. Usually electronics fail instantly and permanently. The fact that it stuttered a few times at low speeds over a couple days, then ran a clean lap around Road Atlanta before stalling, restarting and then quickly stalling again with no restart made me think fuel delivery. I was more than a little surprised when I discovered no spark (after wasting time testing the fuel pumps, relays, fuses,etc.).

I'll pull the plenum cover today and get a good look at the distributor. I understand that it's a weak point, and I belive this is the original 35 year old cap and rotor. No indication in service records that it's ever been changed. I'm half tempted to just replace it while I've got it apart. New ones from r.d. enterprises are fairly inexpensive. It might not be a bad ideas to proavtively replace plug wires while I'm in there since it's pretty much impossible to do that without pulling the plenum cover. 

Speaking of plenum cover... anyone have a source for the gasket? I haven't been able to find replacements online. I'm assuming that they are no longer available. It looks like a simple paper gasket though, so I can make one from Fel-Pro gasket material. If I get ambitious I'll scan it and create a template to cut them with my laser cutter. If they aren't available anywhere anymore maybe a few people will have interest in inexpensive pre-cut gaskets. I know I could just use Permatex Ultra Blue, but that's oftern a real PITA to get off, and it's clear that the plenum cover is going to need to come off from time to time. 

 

4 hours ago, CarBuff said:

3. Broken wire INSIDE the distributor that provides a signal to tell the car that the engine is turning over. I've seen the 2-prong plug going to the distributor break, too.

Since it senses the engine turning over with the starter and activates the fuel pump, I'm guessing that this isn't the issue. Or does the fuel pump trigger from some other source? 

 

 

[Oznog]

6 hours ago, jonwat said:

Beautiful looking car, I used to own number 4 of 40 in pearl white just like it here in the UK. To add to Filip's suggestions to look at is does it have an immobiliser that's acting up? Definitely sounds like an ignition problem though.

I'm not aware of any immobilizer on this car. Was there any "factory" immobilizer or would it be an aftermarket system? 

[jonwat]

43 minutes ago, Oznog said:

Was there any "factory" immobilizer or would it be an aftermarket system? 

There wasn't a factory immobiliser on my UK car, I had to have one fitted before they'd insure it.

[Steve V8]

5 hours ago, Oznog said:

Good to know it's a GM pert than I can hopefully source locally.

The AB14 ignition amplifier is a Lucas part, well known for failing, definitely fitted to the V12 Jaguars (the one on my XJS having failed), and probably other British Leyland models.

[Oznog]

Found this while searching for AB14 information.... Lucas Diagnosit cards for various ignition systems. Card #6 is the process I needed! Haven't had a chance to get over to the shop to run the test, but hopefully this will help me isolate what componnet had gone bad. 

https://mossmotoring.com/lucas-diagnostic-aides/

 

[ramjet]

Coil?

[Escape]

8 hours ago, Steve V8 said:

The AB14 ignition amplifier is a Lucas part, well known for failing, definitely fitted to the V12 Jaguars (the one on my XJS having failed), and probably other British Leyland models.

While the AB14 is indeed Lucas, and used in many British cars in the 80s, the internals are actually GM. Or at least compatible with a GM amplifier. The AB14 as a whole is difficult and expensive to source, but the internal GM HEI 4-pin module is readily available it seems. (you know this of course, judging from your prior posts on this subject 😉 )

Still need to determine if it is the AB14 at fault or not of course.

[jonwat]

17 hours ago, Oznog said:

I did confirm 12v at the coil

Anyone know which year did Lotus stop using 6 volt coils?

 

17 hours ago, Oznog said:

I'm half tempted to just replace it while I've got it apart

Silly not to as they're so cheap.

[Escape]

1 hour ago, jonwat said:

Anyone know which year did Lotus stop using 6 volt coils?

I don't think there's a clear cut off. My Elan has a 12V system, but a friend's, also from 73, still has a ballast.

[CarBuff]

3 hours ago, jonwat said:

 

Silly not to as they're so cheap.

Just be aware...auto-store aftermarket parts can have a short lifetime.  🤢  If you replace the HEI (GM High Energy Ignition) module, don't throw the old one away unless your issue is resolved.

+++++++++++++

21 hours ago, Oznog said:

Speaking of plenum cover... anyone have a source for the gasket?

 

Not knocking Ray P from RD Enterprises, but he specializes in older Lotus'. Worth a call, though.

 

In the USA, one of the best Esprit parts sources is JAE Parts in California. CALL until you talk to them. (Don't email or rely on their website)

http://www.jaeparts.com/

They will have the plenum gaskets.  I always keep an extra on-hand...but I also agree, generic cardboard gasket material works fine in that application.

Easy to trace and trim. <--proof once again, that everything you need to know in life, you learned in kindergarten. 😁

 

Make sure you torque the plenum nuts to spec, too. Remember, CIS requires a sound, sealed intake system.

 

If you give up, locate a shop that works on older BMWs, Volvos, Mercedes. or <<Gasp>> DeLoreans, as they will be experienced in CIS systems. "Bosch CIS FI doesn't throw CODES...it throws FITS." 🫣

[CarBuff]

21 hours ago, Oznog said:

Was there any "factory" immobilizer or would it be an aftermarket system? 

Any alarm system would be aftermarket. I've seen more than one period Esprits with spaghetti hanging under the dash from careless installers. (Period car phones, too)

 

21 hours ago, Oznog said:

Because of the way it failed I really though it was going to turn out to be a fuel issue. Usually electronics fail instantly and permanently.

Not the case, with the distributor-pickup wiring issue. As stated, the fuel pumps are inhibited if the car doesn't sense engine (distributor) rotation.  That one, last strand of wire can make & break in an intermittent way.  The circled area at the picture shows the stress point.

If you noticed any 'flutter' of the tach, that's a good indicator that the pickup and wires in the distributor need to be replaced.

[Oznog]

OK, more weirdness now that I've dug into this. The AB14 ignition amplifier isn't being used at all. Totally disconnected.
I recall reading somewhere that there was an aftermarket distributor that bypassed the ignition amplifier. Perhaps that's what's in this car and it's gone bad. 
Does anyone have any knowledge/information about these aftermarket distributors? The only thing I found searching was a reference to an eBay seller named  SimonBBC. 
I guess I'm going to have to bite the bullet and pull the plenum to get to the distributor to see what I'm dealing with here. If it is the aftermarket distributor, I'm guessing it makes sense to replace it with an OEM one and fix the wiring to put the AB14 back in line. Hopefully, I can figure out how to do that...

[Escape]

I don't know about Lotus or Esprit specifically, but during the 80s several cars, for example with the Rover V8, changed from a separate amplifier like the AB14 to an integrated one on the distributor. As Lucas distributors were widely used, I wouldn't be surprised to find a suitable one with an integrated amplifier. As an aside, if you don't need the AB14, get it to someone who can try it in his car, if it's working as it should, it will be a highly wanted item!

As for taking it out, I haven't tried yet, but know you can get the chargecooler pump out on the later engines without removing the plenum. So it may be possible to get the distributor out as well.

[Oznog]

Without taking the dizzy apart (my next project it seems) it looks like this has the Pertronix conversion (1847V?). Seems like I've read some very mixed reviews of this setup regarding long term reliability. I think that the AB14 may have died and they "fixed" it by converting to the Pertronix. Based on what I've read, it's better to go back to the original Lucas / GM setup (assuming I can source all the parts). 

Another thing I've discovered is that the Pentronix Manual specs a 3.0 ohm coil. This car seems to have a 1.5 ohm coil. I think the stock Lucas / GM setup uses a 0.6 ohm coil.  Given that, I think that this is the wrong coil for either setup. Does that seem right? 

Any insight from this group on the Pertonix positives or negatives?  

[JimmytheTurbo]

Check the dizzy is going round if you turn over the engine.

I had many of the issues you describe and turns out I hadnt tightened the dizzy up and the spring had pushed it off the drive so it wasnt turning.