[pic76]

I've been having problems with my diesel. I love my truck but would love it more if it would run properly and not stall on me. This afternoon it died on me and now won't start at all. I'll start by filling out the following questions:

1.Lift pump test - describe results - Not done since it won't start.​

2.Service Engine Light - intermittent
3.Model year - 1995
3a. Odometer reading - 166000
3b. Miles on major engine components if been replaced - n/a
4.Do you have any engine codes? Yes
5.If you do have engine codes - 17, 18, 35, 36, 54
6.Air Filter condition (visual check) K&N, fairly clean
7.Fuel filter condition - probably about 20K miles on it
8.Condition of Battery terminal connections - cleaned and tightened
8A.Known condition and age of the batteries. 2 yrs old and 3 yrs old
8B.Are batteries of differing age or are they a matched set? not matched
9.Upon cold start, does the radiator hose get hard quickly? Don't know
10.Upon cold start, do you have excessive white smoke? No
11.Do you have excessive cranking time before the engine starts? No
12.Have you used the block heater, and does this effect engine starting? No
13.During hard acceleration, do you have excessive black smoke? No
14.Do you have any unusual exhaust smoke issues? No
15.Turbo check out - Don't know, won't start
16.Do you have an EGR on the engine? S engine code
17.Indicate if you know if it’s a 2500.
18.Indicate fuel that you are using: #2 Diesel,
19.Are you using any fuel additives? Not currently.
20.Please indicate geographic region you are in: San Diego, CA
21.Do you have any service history available that might pertain to the problem you are having? Replaced FSD 3 times over the past 4 years
22.Please indicate any modifications to the vehicle that might help us diagnose better. No mods, all stock.
23.Upon unscrewing the fuel cap, do you have a large vacuum formed in the tank? yes
24.Location of PMD/FSD? Mounted on the fuel pump.
25.Are ALL glow plugs in proper working order as per this thread? Yes.

Over the past few months it has been giving me grief while driving where it will lurch and jerk (usually indicating FSD problem) but once the Service Engine light comes on it continues without a problem except for decreased power. At $400 a pop, I'm tired of replacing the FSD which only corrects the problem for a short period of time. Any help that can be offered will be greatly appreciated!

Thanks,

 

[knkreb]

First off, congratulations on using the diagnostic checklist. Very helpful info, and helps cut to the chase of what the real deal is.

Lift pump test can be done on a 95, yet it requires cranking to git-r-done. Cranking will pressurize the oil pressure switch and energize the lift pump. As long as you have oil pressure, you should have lift pump purring away and fuel coming out of your water drain valve when opened. Read as: may be a two person job, just watch your knuckles with spinning fan blade. No fuel could either be a bad OPS or bad lift pump.

Fuel filter is due for change by mileage alone, get a new one and compare the color of new to old when replaced, you may be surprised.

Check condition of IP wiring connections. That may be the source of the 54. Bad connections will result in some bad readings to the ECM, and throw a bunch of codes.

Try keeping the fuel cap unscrewed for a while to see if that helps. (read as, replace it for all of $5 +/-)

Chances are you have 3 good FSD's if you still have them.

To summarize, your realm of possiblities are:

1. fuel supply issues with older fuel filter, unknown lift pump, and vacuum in tank.
2. Electrical connections are funky.
3. Optical sensor filter harness (if so equiped) maybe giving you fits too. Known to cause some issues with communication between ECM and IP.

 

[DavidPhillips]

My 95 has seen all of these codes from time to time. More recently it started getting a single code 18, and 17, 18, and 35.

It also started going dead at random times while driving or idling.

A couple of days ago I could not go anywhere without it going dead. It would not sit and idle or run down the road without either going dead or going into limp mode.

I checked the PMD with a known good one and there was no improvement, I looked at the fuel which was clean and I have good fuel pressure. I removed the filter harness and there was no change in the condition. Then I changed the optical sensor and have driven it over 500 miles without any sign of a problem. The filter harness is still not installed. I'm not sure I need it since I have seen no trouble codes yet.

It's not a cheap part and it's not something that is recommended to change without pulling the pump and aligning the optical sensor on a test bench. However I did not want to take the IP off and I know that others here on the forum have successfully replaced the part on the IP with it installed on the truck.

If all other efforts to find this problem fail. Consider the optical sensor.

 

[pic76]

Thank you for the help thus far. I'm going to try your recommended steps. Could you clarify the "Check the IP connections"? Being in Internet Tech Support for the past 10 years, the first definition of "IP" to me is "Internet Protocol" and would make me question how long my truck has had an internet connection?

 

[DavidPhillips]

Injection Pump

The heart of your engine that sits in the middle of the engine up front and has fuel lines from it to the injectors.

It has a connector on top for the optical sensor where the filter harness is located, a connector down low on the passenger side for the stepper motor, and one for the metal pole looking solenoid which is the engine shutoff solenoid or fuel shutoff solenoid. The solenoid has a ground mounted to the IP itself. The harness there runs from the firewall area where there is another large connector.

There are also various grounds from the batteries, on the intake manifold, and down by the passenger side exhaust manifold.