High RPM Miss

[TheNicky]

Me and a friend have been prepping for dreadful CA smog
and my 83 ranger is just about ready however....

I have what seems to be an electrical miss...
its only happens at high RPM's which screams electrical to me...

I have brand new
-Cap
-Rotor
-Plugs
-Wires
-Coil
-Carb rebuild

Timings on!
New Grounds!
Compression in all 6!

im so lost now...
and i have until end of august to get all my crap done

so anyone have a similiar problem and gimme a good spot to check and or fix let me know

Thanks TRS

 

[dangerranger83]

How high of rpms? The only thing that you didnt replace in the ignition system was the TFI module, not saying its bad though or your problem. Is your timing advancing like it should be?

How do they test in Cali.? Do they test it into the high rpm's where you say its missing?

Emissions testing....whats that...LOL...just kidding, I hope your truck passes so you can drive it, I've been waiting to hear if you could drive it or not.

Does it have a new CAT on it? I know they are costly but it might help you out.
Does the smog air pump thing work right? My dads has it, mine has nothing but a CAT.

Hope you pass the test and if so give a shout to us.

 

[TheNicky]

RPMS to about right before shifting...

wierd thing is it doesnt miss all the time sometimes it does it alot then it doesnt do it at all

and forgot to mention new TFI as well...
even fixed the wiring to it becuase the other one was all screwed up..

and yea 10 degrees

And they do the test at 15mph and 25 mph

and if the guy smoggin isnt shifting it too soon it will miss unless i fix it and id rathe rfix it then take the chance it miss or not

it has a newer cat... or so it seems and a new muffler i welded in!

 

[Eric Kropp]

I have had two different types of miss at highway speeds. One was more annoying then problematic. It turned out to be carburetion, don't know exactly what as I just sent the carb in for rebuild...life time warranty, ya know. The other time was way more serious. It would miss and bonk and learch at 60mph or so and if I put the clutch in and let it idle down while coasting it would go back to normal. That one turned out to be the map sensor. The smog place I go will test my emissions at idle and at 2500 rpm and tell me if it is with in limits. I would see if you could find a smog place like that. If they have it hooked up to Sacramento and it fails you have real problems. I have been getting my through smog every two years with out any major problems and I fix what ever is wrong the right way every time so I won't have problems in the future....Get ready everybody, the new admistration is going to want all the states to smog everthing every two years...just like us lucky guys in California.......

Eric Kropp

 

[TheNicky]

Well the guy before me took it to smog 2 times after he bought it and before he sold it
Failed both times... as gross polluter...

But i have replaced close to everything that would make it fail besides this damn miss...
and i cannot for the life of me figure it out... i have a fresh rebuilt carb...

could it be the tuning?
i have not tuned it yet but plan to i just didnt think it would miss liek it does at high rpms (just about to shift) but thats what i thought haha

 

[dangerranger83]

I've read that people couldn't pass smog and brought it to a machanic and they couldn't figure out why it couldn't pass smog so they were allowed to drive there truck but only because of that.

As for my truck I got it running with the TBI and wow does it run nice....for the 2 minutes I had it running due to no exhaust system so it was quite loud.

Does it cost you anything to get your vehicle put through smog? Mabey the miss wont happen during the smog test.

 

[TheNicky]

ABout 60 without a coupon

 

[Eric Kropp]

Every truck can pass smog. Just need to find the problem. Before you sweat the miss to much, see if you can get chummy with one of the smog techs and have your exhaust anylised(?) at idle and at 2500 rpm. If it passes those two tests, then it is a visual and everything just has to look the way it did when it came from the factory. You may not need to worry about the miss affecting the smog test. Any chance you have a bad plug wire/s? Also if the idle/air adjustment screws are out more than 1-1/2 to 2 turns it will probably fail the idle smog.

Eric
erk4@pge.com

 

[TheNicky]

Like i said i have not tuned the carb yet i was gonna have professionaly done before the test...

No loose wires... new gapped plugs checked about 10 times haha

It should pass visual i dont have leak valve stem seals anymore haha...

and eric you were talking about a map sensor? how can i go about looking into mine?

im just really running out of things to replace...

im gonna swap 1 more coil today... see what happens

 

[dangerranger83]

I dont think the carbs. have MAP sensors. My dads doesnt and its basicly the same thing, all it does is have the vaccum line to the relays and a million vaccum lines from that. I think there are 8 different exhaust emisson system set-up.

I'd do what you said you are going to do and take it to a pro. to get it tuned. If the exhaust emissions system is the same as the factory set-up then theres nothing they should be able to do. Does your truck originaly come from California? If not then it might not meet California's emissions standards.

60 bucks...good gravy, the government will do anything for money.

BTW your one post away from 300. Had to say it. Keep us updated.

 

[TheNicky]

300! yay

umm thats what smog shops charge... not sure how much the gov see's of that if any...

but yea it sucks... and i dont know about my car and its whereabouts...

all i know is i have replaced almost evrything to make it pass haha..

 

[Eric Kropp]

The MAP sensor is located on the inner fender on the right side near all those vacuum solenoids. I don't really know how to check one. I got lucky with mine because the Ranger was acting the same as my wifes '85 T-Bird, and that is what a mechanic changed to make it run right. I am not clear about your plug wires yet. Have you checked them with a meter yet? I forgot about the third time my truck had a freeway speed miss. My plug wires would "break down" as the engine warmed up. By the time I was up to freeway speeds the wires got hot enough to start faulting and causing a miss. Also...make sure when you are timing the engine that the "spout" wire in unhooked by the distributor.

Eric<><

 

[dangerranger83]

You must have a special truck Eric. My dads doesn't have one. We have had his wiring harness out a few times and I've never seen one. My TBI system I put on mine has a MAP sensor on it but none of the vacuum relays are hooked up just it.

 

[Eric Kropp]

Both of the Ranger's I've had have MAP sensors on them and I have taken a few MAP sensors off to Ranger's at the junk yards. I would be pretty confident saying that a MAP sensor is the norm for a carbureted Ranger. It makes sense that it would have one as the computer gets the intake manifold pressure information from it. I just know mine was bad and drove like a new truck with a new one.

Eric<><

 

[dangerranger83]

Got a picture of it, just out of curiosity, mabey my dads does have one and we have over looked it. Might be the reason its getting poor fuel mileage or something.