ahh! help having majpr problems

[shorty10]

i just got my 1.7 73 back from the shop new plugs points cap button wires and fuel pump also the wiring was replaced since some were burnt up well I was driving home and the car started to back fire when i hit 4000 rpms id let off the gas and it would back fire quietly and around 3 to 5 times put put put
well it stalled and it wouldnt start unless i kept the gas peddle down and it would slowly start back up well i heard a loud bang later that evening and it stoped so i put it into gear 3rd and popped the clutch . it started for only a second and the rpm tach was going from 0 to 4000 back and forth really fast ....weird
and then it would not start as i was sitting there i heard a strange noise coming from the gas tank , like a gurgling sound hmm and the car smelled funny as it is was fludded well i waited 15 min started it and bam! tried again and it started just fine then i drove it home and parked it ...
well 1 thing i know for sure is that i gassed it up ot the rim baforee and a day later aroung 178 miles later the gas gause read a quarter running rich me thinks and a mechanic friend of mine told me that i had an exaust leak somware

help meee!

[Jason Porter]

I'd check with the simplest things first:

Firing order, points gap, timing.

Check your temp sensor, your trigger points in the bottom of your distributor.

Make sure the ground wires for your injectors are connected.

Check to see if your MPS is holding a vacuum.

Fuel pressure should be around 28-29 psi.


Anybody else remember anything else? I haven't jacked with D-jet in a while...Thanks God!

[Dave at Pelican Parts]

Check the valve adjustment and compression, as well.

--DD

[shorty10]

mps check how? how should i check my Fuel pressure
temp sensor cylinder head temp sensor???
sorry 22yr 1st porsche

[Dave at Pelican Parts]

This site contains all of the D-jetronic info you could ever use....
http://members.rennlist.com/pbanders

MPS check: Check the resistance through the coils. I think it's the two outer pins, and then the two inner pins. One will be in the 350-ohm range, one in the 95-ohm range I think. Then get a vacuum pump (like the Mity-Vac) and see if it holds about a 15" vacuum for 5-10 minutes.

Fuel pressure: T a gauge into any of the fuel lines "downstream" of the fuel pump and "upstream" of the fuel pressure regulator. (Probably an easy one is to replace the Cold-Start Valve with the T for the gauge.) Make sure the gauge can measure up to 40-50 PSI and is compatible with fuel. You should see 29 PSI at all times that the pump is running.

CHT sensor: Unplug it from the wiring harness and measure the resistance from its plug to ground. Should be about 2,000 ohms when cold and <200 ohms when the engine is warmed up.

Check through the Brad Anders site mentioned above for the specifics of the above, and lots more info.

--DD

[Tidybuoy]

Did you by-any-chance have the valves adjusted?

I had a similar problem a few years back. I took my perfectly running '74 914 1.8 into a shop and had the valves adjsusted & some minor tune-up stuff.

When I picked up the car, it ran fine. However, after a short 2 mile freeway drive, it started back firing and eventually died and needed a tow back to the shop.

The shop gave me a bunch of excuses and told me that other things must have gone bad - specifically, they said it needed a new air valve.

Not trusting this shop (i.e., German Auto of Fresno Ca), I took it to my old but trusted shop (LLoyds Autowerk Statts of Fresno, CA) and the first thing they did was a compression check - which showed horrible results.

To make a long story short, the first shop adjusted the valves incorrectly. They actually turned the engine in the wrong direction (due to the fact that a 914 engine is backwards - compared to a bug). Therefore, the engine was rotated 1-4-3-2 vs. 1-2-3-4.

This may not be the problem, but it's worth thinking about.

Vern

[shorty10]

valves havent ben ajusted for around 8000 miles
just had a compression check and its good

[chrisreale]

maybe adjust the valves....

[jkeyzer]

it started for only a second and the rpm tach was going from 0 to 4000 back and forth really fast ....weird
and then it would not start

First thing I would check is the POINTS! A bad valve adjustment will not cause the tach to fly around, but burned/misadjusted points will. They will also cause loss of power, backfiring, and starting problems. I fought points for a long time in my last car, I know! Get a Pertronix in there asap, or at least a new properly adjusted (check the dwell and timing) set of Bosch points. Make sure you lube the fiber block of the points and the distributor cam too, or they will wear quickly and leave you stranded on I-5 in the middle of nowhere. At least that's what happened to me!

[Tidybuoy]

I would agree with jkeyzer. The first time I read your post, i missed the part obout the tach bouncing around.

Besides the points, you should also check to make sure the coil is wired properly as one of the coil wires operates the tach.

[shorty10]

ajust the points ? how. and lube what? and what lube... plane grease?

[Dave at Pelican Parts]

What? Airplane grease?

Plain regular grease is OK, but not optimal. We sell a Bosch grease specifically for points (also trigger points on the D-jet cars). It comes in a ~3-oz tube, which is about a ten-lifetime supply... (Rats, I gotta find my tube!!)

--DD

[shorty10]

well i saw smoke coming from the car near the new fuel pump(worried its the fuel pump since the buzzing wontg stop) and i think i found my exaust leak right where the heatexchanger splits for the heater box it looked as it was dripping with gas or oil ?? (exaust leak?) ans whitish smoke was coming from it well i got into the car and i noticed white smoke coming from the passenger side vent weird since the vent is not hooked up to a blower is this the problem i have with backfiring ..
and i looked at the button and pionts and they look clean and no signs of burning so whats going on ahhhhhhhhhh
oh im getting a triad so ill need new 2.0 heat exchangers
but with my current problem wouldnt i need them anyway?

[Dave at Pelican Parts]

The only way oil can leak out of the heat exchangers is if it's dripping on there from somewhere else. Most likely the pushrod tubes or valve covers, but sometimes it seems like every oil leak in these cars somehow finds its way down to the exchangers....

--DD

[shorty10]

where and how do i apply the grease

[wrongpew]

Check to see if the oil/fuel leak is coming out of the heat exchangers on both or only one side of the car. If it's only on one side, I'd be very suspect of a fuel injector on the same side that is stuck open.