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fastdave92649

Engine won't fire

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Background:

Had the car sitting for a week so I decided to go to the garage and run the engine to warm it up and blow out the cobwebs. Started right up and had some noise in the lifters so I shut it down and checked the oil. Sure enough I was a qt low so I topped it off and restarted. Car cranked over fine and ran great, no more valve ticking. I let the car idle and run for about 20 minutes gave her a few revs and everything was great. I shut it down and went about my holidays.

Yesterday I went out to give her a run and the car will not start. This was only 2-3days after the above where it started/ran fine. I checked the battery and replaced it with several good ones sitting in my charge station, no luck. Checked the oil and it seems high now, not sure if it's overfilled or if that would even cause my problem? I hear the fuel pump coming on (not to be confused with my intercooler pump you can hear in the video). I'm thinking it may be the starter?? I have always seemed to have alternator issues and replaced it but I still have to rev the car up to 3k to get the battery light to go off and get the battery to start charging so it could be that again... :lol:

Thoughts or suggestions on where to start looking at this would be great...

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Dont think its the starter as you normally get a clonk and thats about it. Slly suggestion but has it got fuel? Have you also fitted the correct battery. If the battery power is to low for the vehicle it wont be enough to crank it over. Easy way to check this is jump it off another car to see if pulling the extra power from another battery gives it a boost.

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Dave,

I would try taking an ohmmeter and measuring resistance from the engine to the negative battery terminal, should be near zero. I would wager you have a bad ground, if you don't have an ohmmeter, just put a jumper cable from the negative battery terminal to the engine, anything metal and not painted.

Paul

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Thanks guys..

Although silly I did also think of fuel, I have ~1/4 tank so should be good there. Could it be water in the fuel or a bad tank of gas??

I have tried using a new battery with a full charge so I don't think it's the battery itself, but I have not tried jump starting it off another car yet.

Could be a ground that has gone bad, I will hookup my meter and see.

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Maybe it is cranking normal, mines been broken for awhile, try cranking it with the throttle floored. According to the manual it should crank with the ECU not injecting fuel when the throttle is floored.

Edited by 97-Esprit V8

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Dave,

I would try taking an ohmmeter and measuring resistance from the engine to the negative battery terminal, should be near zero. I would wager you have a bad ground, if you don't have an ohmmeter, just put a jumper cable from the negative battery terminal to the engine, anything metal and not painted.

Paul

Ding Ding Ding... we may have a winner.

Took my ohmmeter and tested the resistance from several points on the engine to the negative battery terminal. Read on average 5.5 on all areas. I have not put on the scrubs and crawled under to verify and check the grounding straps and points yet but hopefully it will be a simple fix.

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do you have an spark !?

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If you have no spark, then verify the inertia (rollover) switch didn't get tripped, seems strange that it would. If that's Ok, Maybe something happened to the cam timing sensor as the ECU verifies the timing relationship between the crank sensor and cam sensor before allowing the spark to occur.

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Happy New Year!!

..I'm not a big fan of watching sparks fly to verify plugs and wires ..

why not, as this is an easy costefective thing ! Undo the covers, pull the cables ,undo the spark-plugs, fit every plug in the right cable -and hold every plug on an bare (not painted) piece of engine that is in contact with ground. You can use rubber gloves, in case you fear anything on 'high current'. In normal cases the spark (even if it is an bad spark that goes on the outside of the spark-plug -insulator..) is covered by the cable-plug. Important thing is only to hold the spark-plug on something with 'ground'.

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Time for an update:

I used the grounding method to determine there was no spark on both banks. Tried another plug I had in the shop and still no spark. While waiting for my new test unit I pulled the plenum off and cleaned up the bottoms of the coil packs. Wayne suggested I do this last time I took the plenum off and I got lazy and didn't. This time I gave them a good cleaning and greased them up and put everything back together. Still no spark from both banks.

Got my new spark test unit and verified I have no HV coming down the wires and no spark at the plug.

I pulled the crank sensor and tested it, seems ok but dirty like the under sides of the coil packs. I pulled the cam sensor and tested it, not sure I did it right but my meter did not read any Ohm movement on the signal wire. Given that these sensors are vital in engine start and not very costly I replaced both the cam and crank sensors.

Engine still will not fire. What are the odds that both my coil packs died at the same time? What else can I check or test?

I am going to see if any of my local V8 owners can swing by and let me use there ECU to determine if my unit is shot, but it's less than a year old (long story involving a soldering iron).

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have you used a soldering-iron to replace the stock ECM chips !? Maybe the work was not perfect in the end. But for now, just try out to find if there is all OK within the wiring from ECM connector up to the coil-pack.. . All wiring schemes are in the workshop-book

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I tried to solder in a chip about a year ago and failed horribly so I had to get a new stock ECU from JAE. If I can get another ECU to verify that is the issue Jeff and the guys at JAE are more than willing to go to bat for me and try to get it replaced under good faith.

I may also look into the immobilizer? Maybe it took a dump and will not allow the car to fire.

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you have pressed the inertia-switch ?

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Yes i pushed down on the inertia-switch, funny thing I was just out in the shop trying that again. No luck.

Looks like I may be calling Harry over at Viking to:

A. Beg him for a loaner ECU to try that.

B. Tow my car to his shop for a formal diagnosis and hopefully a fix.

I just figured as it started and ran fine and then only a couple of days later with no activity on the car (I didn't touch it :D ) it won't, that this would be a relatively easy thing to track down and fix...

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all ignition & fuel/ECM -fuses and relays are in good shape !? I'm not totally sure that there is no possibility that an minor circuit has fouled up one of the importend circuits than ..?

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Dave I would stop just replacing parts. You are introducing more variables into the problem solving mix. It seems you tried all the "easy" fixes. Without someone with a scope and the wiring diagrams about the only remaining "cherry pick" is to try an alternate ECU. If the plenum is still off, you could scope primary voltage switching into the coil packs. The odds of both coils packs failing at the same are ZERO. Next look at the timing pulses, while cranking the engine, between the crank and cam sensors. If the ECU replacement fails, you need to find someone with a scope and who knows ECU functions.

Wayne

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just as an sidenote, is the rest of the ECM working, or with other words: can you read OBD-data (is the ECM supplied with ground an 'positive' and does work after all.. ) ?

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I tirple checked all the fuses in the car, the only concern I found was the PO used a 10A fuse where the manual says a 7.5A should be in the rear B6 (or B7) slot. I also verified all the relays appear to be functioning properly. When energized they click as they should and I switched the common ignition one with the fuel pump one and the pumps still come on but the engine does not fire.

Wayne I completely agree and as I test items I revert back to the old stock piece if it does not solve the issue as to avoid adding other issues on top.

I have connected my computer and it can connect to the ECU fine and pull data. Looks like I will have to send it off to a professional to get the ignition system scoped.

Thanks for all the help and suggestions.

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As weare talking about an 918engine: Wouldn't an timing issue mean valve to piston contact on the one hand, and at least (if the disarrangement is minor..) error signal between crank and cam-shaft sensor !?

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Time for an update and I wish it was good news.

Harry pulled the cam covers and turned the crank manually and the cam's do not turn. Left bank cam bolts are very loose right side very tight. Could be the chain or something else but bottom line is the engine needs to be pulled and rebuilt. :)

I am now stuck with the tough decission of:

A. Rebuilding the 918 with forged pistons and ARP studs with a complete balance etc.. (12-15k).

B. Pulling the engine and trans and dropping in a supercharged LS7 and inverted G50 (not sure yet, still looking at sources for this option).

If i go B I could sell off my intercooler and other parts and pieces to offset the new engine and trans or keep it all and have it rebuilt at some point down the line. I guess I could also just stick it back in the garage and let it sit if I chose to rebuild the 918.

Thank you all for your time and efforts,

Dave

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For what it is worth, I would invest in the engine rebuild.

Sorry I posted before I was finished.

The reasons to rebuild are:

1. you would probably have more time and close to $15K invested anyway and they you would have a odd bar car with no chance to recover you investments.

2. You might be lucky and not have such an expensive rebuild.

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Dave,

I'd go with the rebuilt 918, and FWIW if you put a LS7 in you're going to run into all sorts of issues with CARB and smog testing.

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