Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Carburetors > Not firing on front 2 cylinders

 Moderated by: Greg Fletcher
New Topic Reply Printer Friendly
Not firing on front 2 cylinders  Rating:  Rating
AuthorPost
 Posted: 04-13-2007 03:12 am
  PM Quote Reply
1st Post
Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
    Car was running great.  I changed the oil and decided while I was down there I should do a little more degreasing.  I have been cleaning things up slowly and I decided I could shine things up a little more.

On a warm engine I used a little simple green and then hosed things down - gently. 

I started the car up to warm it back up and get all the H2O to evaporate.   I even took a towel and cleaned out around the plugs etc.

Now the car isn't firing on the front 2 cylinders.  I have spark.  The front plugs looked really bad - no fire so they were wet and sooty.  I swapped the front 2 plugs with the 2 rear plugs.  Still no fire on the front - the rear 2 fired up fine. 

If I pull a plug and ground it out on the head - I get spark.  It might not be the strongest spark I 've ever seen but it seems like it should be enough to fire. 

It's been run down the road more than 10 miles - mebbe 20 - so it's been warmed up sufficiently to dry everything out.

I'm wondering if something is wrong with the front carb.  Thinking this I sprayed some carb cleaner in the carbs to dissipate any h2o that might have been in there.  Still no fire on the front 2. 

I'm running Dell 40's. 

This is kind of silly.  What do you think I did?  Any ideas?  I was thinking of putting in new plugs - but swapping front to rear didn't make any difference.  The front carb has good 'suction' when you put your hand over the stacks - seems equal to the rear carb. 

Ideas?  My mechanic is far enough away I'd need to trailer it up so I'd be berry berry happy if I could get the old girl running right.  2 cylinders isn't enough for me - I have a hard time just making up the hill to my house!


Back To Top PM Quote Reply  

 Posted: 04-13-2007 07:35 pm
  PM Quote Reply
2nd Post
frank12873
Member
 

Joined: 03-22-2005
Location:  
Posts: 30
Status: 
Offline
My car (with Stroms) does this also, usually after sitting for a couple of weeks. I've always been able to get the other two cylinders making power by tapping (USUALLY lightly) on the carbs and then driving a short distance.

One good thing about this is, it feels really cool when the other two cylinders kick in as you drive!

I've always thought that, in my particular case, either one of the carb jets is clogging up, or one of the floats is sticking and starving a carb of gas. The tapping has never failed to get things working normally again for me. I have every intention of rebuilding my carbs someday, using Mark's tech article as a guide, but haven't gotten around to it yet.

Good luck!

 

Back To Top PM Quote Reply

 Posted: 04-13-2007 08:38 pm
  PM Quote Reply
3rd Post
Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Sounds like you have a sticky float.  I'm not sure that's my trouble. . .


Back To Top PM Quote Reply  

 Posted: 04-14-2007 02:05 am
  PM Quote Reply
4th Post
Jensen Healey
Super Moderator


Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 983
Status: 
Offline
Back to basics. You hosed the engine with water and now the car runs poorly. Have you removed the dist cap and applied the WD-40?

Back To Top PM Quote Reply

 Posted: 04-14-2007 03:52 am
  PM Quote Reply
5th Post
Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
Kurt may well have the right of it.  Sometimes all it takes is a virtually invisible film of moisture inside the distributor cap, particularly if the cap is old and some carbon dust from the rotor contact button is also present.

I'll take this opportunity to comment that dielectric grease, available at most auto parts stores, is great for making a car's ignition system quite water resistant.  Simply apply thin rings of the grease to the base of the dist. cap where it attaches to the body of the distributor, and to the open ends of the boots on each high voltage wire.  Just keep the grease away from the electrical connectors themselves.

Back To Top PM Quote Reply  

 Posted: 04-14-2007 03:29 pm
  PM Quote Reply
6th Post
Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
First thing I did was take off the dist cap and make sure it was dry and the contacts were clean.  I'll give that another shot though. 

I've given her a day to think about the error of her ways.  Now I can get back on it.


Back To Top PM Quote Reply

 Posted: 04-25-2007 02:23 am
  PM Quote Reply
7th Post
Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Mystery Solv-ed!

Damn, I went thru a bunch o little stuff.  Dried everything out w/ WD40.  Cleaned plug wires, used carb cleaner on the carbs to dry them out.

And then, I replaced the plugs - didn't do it.  Replaced the plug wires - didn't do it.  Finally, replaced the rotor cap - Guess what?  NOW I can see the hairline crack on the inside between two electrodes.  Probably between 3&4. 

Now, if I can just figure out why my brakes is acting funky. . .  They seem to be sticking so that they only work on one side - and maybe only on the front (on one side) once in a while. 

Ummmm, it's been a little hairy a couple of times.  Like that time I was doing 100mph on the freeway and the car pulled over in front of me. . .  Oh yes, and the time I was racing around the mountain roads with Dana who also has a JH and it felt like only the right front brake was working - and working well.  Fortunately, I coming into a tight left hand curve - hot. . . . that made me glad I could slide around a curve at 50mph. . . .

Any ideas on the brakes?

Cheers,

Back To Top PM Quote Reply  

 Posted: 04-25-2007 05:16 am
  PM Quote Reply
8th Post
Mark Rosenbaum
Member


Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
Joel wrote: Now, if I can just figure out why my brakes is acting funky. . .  They seem to be sticking so that they only work on one side - and maybe only on the front (on one side) once in a while. [...] it felt like only the right front brake was working - and working well.

Most likely that would be due to shredded lining on the brake hose to the sticking side -- the hose acts as a one-way valve and allows brake application but not release.  Or the hose to the dead side could have collapsed internally.  The OEM brake hoses seem to have a lifespan of 30-35 years, so any original hose can be expected to fail without warning at any time.

Another possibility is one or more sticking caliper pistons.  Naturally one might have both problems at the same time.  The JHPS Club Store and Delta Motorsports offer quality brake parts for very reasonable prices.

Back To Top PM Quote Reply

 Posted: 04-25-2007 06:02 am
  PM Quote Reply
9th Post
Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
It's even more perplexing b/c it's not consistent.  It seems to usually be the right side pulling.  But on occassion it's the left.  I'm thinking new lines all the way around. 

I've never been happy w/ the brakes.  Even w/ new pads all the way around and a new master cylinder I don't think I can lock them up.

And what I mean by 'sticking' isn't that the brake doesn't release.  Poor explanation on my part.

What's happening is that upon hard braking it feels like the only tire braking is the right front.  Very hard dive to the right almost uncontrollable at high speeds.  And on other occassions it dives left - but not as drastic as when she goes right. 


Last edited on 04-25-2007 06:04 am by Joel

Back To Top PM Quote Reply  

Current time is 09:24 pm  
> Jensen Healey & Jensen GT Tech > Carburetors > Not firing on front 2 cylinders Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems