CCCUK logo

 Lancaster Insurance

Website Control

Recent threads

New Forum Posts

» New owner by roscobbc on Sun 17 Jun 18 23:20

» 2018 LeMans by chevrolet on Sun 17 Jun 18 18:28

» FOR SALE - 1966 Corvette Stingray C2 327/300hp 4 Speed Manual Gearbox by veeeight on Sun 17 Jun 18 17:59

» c5 alarm fob by Ruby 2 on Sun 17 Jun 18 17:01

» STOP PRESS ADDITIONAL BREAKY MEET AAC UK Summer NATS by Daytona Vette on Sun 17 Jun 18 16:21

» What did you do with your Vette today? by FelixP on Sun 17 Jun 18 10:22

» A Beautiful Day For A Car Show by C7KEN on Sun 17 Jun 18 00:13

» Rockcliffe Hall Supercar Show Sat 16th June by C7KEN on Sun 17 Jun 18 00:02

» Kimbolton Country Fayre 8th July by autocolor on Sat 16 Jun 18 20:25

» c5 finally by Invetterate on Sat 16 Jun 18 18:42

» Water pump leak. by MIT on Sat 16 Jun 18 12:03

» c5 repairs and servicing by cloudedmind on Sat 16 Jun 18 09:37

» C5 Z06 for sale by yenko 1969 on Sat 16 Jun 18 08:51

» C5 wanted pref cab or coupe yellow by Celcius on Fri 15 Jun 18 17:56

» Front indicator/side light mod without switchbacks by MIT on Fri 15 Jun 18 17:55

» Breakfast / Evening and end of an era Club Meet Midlands Area by Daytona Vette on Fri 15 Jun 18 13:34

» How many corvettes by L88 on Fri 15 Jun 18 10:58

»  by H3JLV on Thu 14 Jun 18 17:23

» 68-82 Brake Calipers by roscobbc on Thu 14 Jun 18 16:44

» Vulcan Tour 2018 by Bowler on Thu 14 Jun 18 15:02

» Oliver Gavin's old "Company car" (?) still for sale by chevrolet on Thu 14 Jun 18 13:04

» Beautiful E-Car by CaptainK on Thu 14 Jun 18 11:39

» AMERICAN SPEEDFEST on 9th /10th JUNE 2018 by curious bystander on Thu 14 Jun 18 10:38

» '85 C4 Wheels & Centre caps for sale by chevrolet on Thu 14 Jun 18 09:48

» car stereo by dex99 on Wed 13 Jun 18 20:40

» Latest cars with "smart" alternators won't charge up a connected device by chevrolet on Wed 13 Jun 18 19:59

» Some Subtle Mods to my C7 Stingray by chevrolet on Tue 12 Jun 18 21:32

» Dead battery, power window closing. by chevrolet on Tue 12 Jun 18 19:50

» New uk owner by Sid.123 on Tue 12 Jun 18 14:56

» New alloys - size advice by Sid.123 on Tue 12 Jun 18 14:53

L98 Misfire problem


Go to page: Previous / 1, 2


Reply to topic
View previous topicEmail to a FriendPrinter FriendlyView next topic

Author

Message

Sid.123

Club Member

Mon 09 Oct 17 19:22


I was going to suggest a vacuem leak as did roppa as mine had an initial flat spot on acceleration which I found to be caused by perished 30yr old vacuem pipes....
But if you say number 7 plug was black/rich it could be that athough the injector may be clicking it may be stuck open.I would try cleaning the plug and running with the injector unplugged to see if the plug still gets wet etc or run it with the plug out while unplugged to see if fuel is ejected from the hole.


--------------------
59/69 silver beige/medium brown. 1 of 1,014 in 1986. C4 glasstop

Reply with quote

Manj82

New Comer

Sat 14 Oct 17 23:21

Re: L98 Misfire problem


I'm chasing a miss on a LB9 Trans Am so will watch this with interest Smile

Noticed you mentioned you replaced your injectors with Bosch D3's. Have you checked your fuelling after this and what's your crank times like

I query as I changed the injectors in my trans am to D3's (that according to a vendor were supposedly a like for like replacement) and the car was running pretty lean according to a scan of the fuel trims; BLM high 140's, low 150's on idle and max out at 160 in some cases when driving. Had I not had a scan tool, I would've been clueless about this other than an occasional lean surge

I had to burn a chip with adjustments to the injector constant and some other tables to get the fuelling close to the desired 128.

A google search whilst diagnosing found that quite a few people experienced similar lean conditions with their TPI cars (L98, LB9) and had to pull out the laptop...

just thought to mention

Reply with quote

FelixP

Addict

Wed 08 Nov 17 10:55

Re: L98 Misfire problem


I finally got to the bottom of this and it was a cheap and easy fix!

When I changed the leads a few had got a little too hot near the headers despite having those socks on the boots. When I put new leads on, I didn't take the boots off to slide on the heatshields. Anyway, I started it up and now we have darker evenings, I saw one of the leads shorting against the header!

I'll have to run them very neatly. I was using Summit racing leads but had put new AC Delco ones on, I guess the insulation isn't as good, as they were further away from everything previous but still the spark jumped across. Thank you daylight savings! And a good lesson in checking & double checking the simple things silly


--------------------
1989 Corvette C4 L98 6 speed ZF with Z51 & FX3

Reply with quote

chevrolet

Club Member

Wed 08 Nov 17 12:41

Re: L98 Misfire problem


Well Done/Top Marks Thumbs up So can we call that a "Leaking Spark Plugs Wire" job/fault, as in the Haynes manual Trouble Shooting section above?



Last edited by chevrolet on Wed 08 Nov 17 12:45; edited 1 time in total. [66 %]
--------------------
AKA "Silver C6" on Pistonheads

Reply with quote

Reply to topic
View previous topicEmail to a FriendPrinter FriendlyPrivate MessengerView next topic

Go to page: Previous / 1, 2


Permissions

You cannot post new threads in this forum
You cannot reply to threads in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot add events in this forum
You cannot attach files in this forum
You cannot download files in this forum