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bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 8:47 am
by Mac
Hey all,
My pinz is concerning me a little bit....possibly 3 different issues

1) I'm getting very bad fuel consumption..... I have an injection kit on mine (I don't know who's....I got the truck from a guy in Chapel Hill that said he got the truck from the kit designer in Georgia....I believe both are\have been on this site) ... I just filled it last night and took a picture of my KM's so I can get an exact number..... but I believe I'm doing 5-6mpg.....That's low even for a carburetted one, right? ...I may have a leak? I'm not positive, but I thought I left it with 1/8 more in the tank than I saw when I went back.

2) I have what I think are fairly high RPMs for how fast I'm going...and the speedo is way off. I've read around here on that issue and think it's fairly normal for it to be off- but I'm not sure if it is normal for it to be so far off. If the speedo reads 85kph, I'm doing about 44mph... and 3,000 RPM(4500 redline, right?) It does not really want to go any faster than that on flats....I can get it to around 50 on a downhill with some gas. One of the reasons I got a pinz was that it would be faster than my other military vehicles...at the moment...its slower. Can anyone give me some idea what could be wrong?

3) I'm sure I could check my manual, but since I was posting I just thought I'd ask. My light next to my E-brake light randomly turns on for about a second then turns off....I believe it is oil? (to the left of E-Brake light)... Why would it only flash? Is it temp or do I need to add some? (can anyone give me advice on what to add?)

Re: bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 9:57 am
by pcolette
Regarding your item #2 - if it's an electronic VDO speedo you should be able to re-program it for better accuracy. After programming mine with a measured mile it is spot on according to my GPS.
If you don't have the instructions, you should be able to download them here: http://www.egauges.com/pdf/vdo/0-515-012-051.pdf

Item #3 - that's your oil pressure indicator. Check your oil level first. If it's ok then check that the wire connected to the sender is on tight. They do have a tendency to loosen up over time but I'm not sure if this would cause the light to come on.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 10:16 am
by krick3tt
I have that speedo sitting on my shelf in the shop. It died after 2000 miles and I put the old mechanical one back in...now that is dead.
Not having good luck with speedos, hmmmm.

Looked at the link posted but the phone is no longer in service. Anyone have a current number for VDO? Want them to have a look at it.

Morris

Re: bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 11:49 am
by spandit
If there's a big pool of gas/petrol under the vehicle when you return to it then you have a fuel leak... Have you checked that all cylinders are firing? Could account for the low speed and dreadful consumption...

Speedo is a bit high (is the 44mph a GPS reading)? Do you have standard tyres on it as that makes a difference?

Re: bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 11:51 am
by audiocontr
Sounds like youre running pretty rich. This is a function of the ECU and its fuel map. Not knowing which controller you have nor the base map used, its extremely challenging to tune properly. You would need to get onto a dyno, tune the thing with a sniffer and hope to lean it out to a reasonable level. Does your oil smell like fuel?

Jim has a bit of experience with fuel injection but i believe your system is not of his design. It was a right coast attempt from some years ago.

My opinion is get it back to a carb based system for simplicity sake or prepare yourself for automotive engineering trial and error.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 2:56 pm
by Mac
Paul- It is the normal mechanical speedo....sounds like VDO speedo would be easier. Is it possible to adjust a mechanical one? I'll check the oil once I have time to look at the truck again


Spandit- No pools under it...but I'm thinking it would evaporate, no? I have no clue how to test if they are firing or not... Any advice? The 44mpg is a GPS reading...I think the tires are pretty normal sized for it...fairly worn down though. Would an inch of wear make that much of a difference?

Audio- Mine has a knob that I can adjust how rich\lean it is while I drive... If it is all the way down the engine struggles and backfires. Should I try just leaning it out a tiny bit from this? I'd really like to avoid carbs....so sick of having them rebuilt.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Thu Nov 17, 2011 3:04 pm
by spandit
I'd be inclined to stick with the EFI but perhaps invest in a rolling road session with someone who knows what they're doing.

If the speedo is stock then it's not adjustable, as far as I know. Perhaps they're just a bit crap

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 18, 2011 8:12 am
by audiocontr
Im not sure Mac, sounds like a good place to start.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 18, 2011 10:36 am
by Mac
can anyone tel me how to check how many cylinders are running?

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 18, 2011 10:45 am
by audiocontr
This is what i used: http://www.harborfreight.com/non-contac ... erralID=NA

I had a bad #1 spark plug. Ran rough, seemed underpowered.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 18, 2011 3:11 pm
by Mac
....so I just see if one part of the engine isn't as hot?

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 18, 2011 4:04 pm
by NoahDL88
Variation is bad, if one is hotter or colder that will be an indication that something is wrong with a specific cylinder.

Have you started with the basics, ensuring that you have spark and fuel in each cylinder?

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 18, 2011 4:55 pm
by edzz
Item # 1 When was the last tune-up? Set the valves, check the plugs, and set the timing. If you think it’s not firing on all cylinders you could pull spark plug lead one, start the motor and listen if it makes a difference (yes / no) shut off motor reattach plug wire one and repeat with number two, etc.

Item # 3 Are you asking if you may need to add oil? If you are not checking the dip stick with some regularity the answer to all of your questions is to find a good mechanic.

5 – 6 mpg, if it is truly doing this poorly running it much without correcting the problem could cause more serious problems than just wasting gas.

If you are capable of performing the basics of the tune-up do that first then go after the fool injection. If you question your mechanical ability’s find a mechanic to do the work and if he / she is willing help you get up to speed on the maintenance basics.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Sat Nov 19, 2011 3:51 pm
by Jim LaGuardia
Your drivability issues are all related. You have Jake Rabey's kit. Start your diagnosis with a compression test(5 revolutions each cyl), Should be between 125psi-150psi and within 10% of each other.
If you find a low cylinder then re adjust the valves for that one and test again.
Next, find and fix the vacuum leak and set idle to 950rpm.
Use NGK BP6ES or BPR6ES spark plugs for best results, gap to .045" as you are using a wasted spark system.
That should get you started. I use brake cleaner or carb spray to find the vac leaks.

Re: bad mpg, high rpms \ speedo and oil?

Posted: Fri Nov 25, 2011 12:14 pm
by Erik712m
I had Jakes kit. Don't think Jake was or is the best welder. Check the base as most kits were warped, also may have blown a gaskit from back firing. Easy enough to find with brake clean. Also you should have a small programmer where you can follow your O2 Rpm and adjust your map. Don't think i'd just go and play with the Knob blind folded.