Hudy

Did you check these items yet? My crank issue was the FPR. I was also running super rich until a couple days ago and found a faulty O2 sensor. Use an analog multimeter to measure the output. Dan

Okay, this is all great information and advice. Now I need more input, Basecoat / clear coat or single stage paint? I'm fine with this being a 5-10 foot truck. I use it regularly as a work truck and it shows. And clearly, I've never painted before. What's my best bet?

I also use the Hella H4 ECode housings with high wattage bulbs on a harness. We do have LED sealed beam replacements on the trucks at work which are from JW Speaker. They are very impressive, and also very expensive.

I'm really impressed but the wealth of knowledge here, you guys are awesome. Should I shoot both an epoxy primer and a (urethane?) sealer? I assume I'll sand it with a DA sander? What grit will I need? I'm planning to stay as close as possible to the stock Dark Baltic Metallic. Is this something PPG or another manufacturer can match, or do I pick one of their colors that's "close enough"? Thanks again!

Hello All, I'm looking for some guidance on paint. My MJ has major clear coat failure and I'd like to simply just paint it myself. I get the general ideas of prep work, sanding, painting, but I'm not sure how far I need to go with sanding. Must I remove all paint chemically to bare metal, or can I get by with a few hours of sanding, followed by primer and paint? Photos attached to show level of failure. With some guidance I know I can do this on my own.

Lots of weight over the past few years... my MJ served my entire home renovation, and now works my contracting business.

After a few days of driving I’m comfortable enough to report that the fuel pressure regulator fixed it for me also. 5 years of cranking and cranking. Can’t believe it. Thanks everyone.

Finally got back to this today. Under a normal start condition, the fuel pressure regulator has a very small leak. Fuel pressure is ~32PSI. When a no start condition exists, the pressure pressure regulator has a SIGNIFICANT LEAK. Fuel pressure is ~40PSI. So, I also have a new regulator on order. Report to follow when it's in.

Well, looks like my fuel pressure regulator is leaking fuel into the vacuum system. Pulled the vacuum line off to discover fuel dripping from the line. Strange, because I am holding fuel pressure.

Yes, using Cruisers guide checked TPS valued using a mulimeter. Yes, exhaust goes from rich to lean quickly. I am skeptical on the CTS still. I’ll install that tomorrow. Unfortunately I only had the tool for a snapshot and couldn’t keep it to monitor data as the motor heats up.

Yeah... although I don't regret buying the ECU. I'll probably leave the reman installed and put the old one in the basement as a spare. Who knows how long these units will be available for. Anyway: The issue persists with the hot starting. I had adjusted the TPS using cruiser's guide, and actually rechecked the spec a few days ago and it was where it needed to be. Is there more to check here? With the coolant temp at 199*, shouldn't the system be in OPEN loop?

New ECU install, not sure yet on repair status. Turns out the Snapon tool I had was faulty (reading the same even with the ECU unplugged). Located a new tool quickly, readings attached.

I used a resistance chart to determine whether the MAT (manifold air temp) Sensor was functioning properly. I had a spare, so I tested that one first. Used heat gun to heat the unit and a thermometer gun to read the temp, and compared that to the resistance shown on the meter. The spare tested good, so I installed it. I took the existing (old) sensor out, and tested that one, which tested BAD; the values it showed were false COLD. I also have a spare CTS, which I tested using the same method. I haven't installed that one yet. I did receive a new ECU in the mail today. I'll install that tomorrow and report back with the findings. Chart attached. I could see this happening in your case, but in mine I know i'm holding fuel pressure.

I suspect the same. Thanks for all of your help!

These readings are in live data on the MT2500, with a fresh vehicle entry.

D1-5: 12.95 D2-4: Key on: 11.9 - 12.1 start: 11.3 running: 13.8 - 14.1 D1-6 running: 14.5 D1-3 OHM: 0.5 D2-8 OHM: 0.6

Okay, MT2500 readings: RPM: Constantly reading between 800-3000, even with the truck off O2: Jumping from 0.5 to 4.98 INJ (mS): Jumping from 18.1 to 0 Loop status: Jumps from open to closed every 3 seconds Exhaust: Rich / Lean jump ST fuel trim: 162/128 jump LT Fuel trim: 125 MAP sensor (V): 0.7 to 4.6 range, goes up and down MAP sensor (kPa): 25-94 range MAN VAC (kPa): ranges from 2 to 74 BARO pressure: 99 TPS: .66 to 2.5 (at idle throttle %: 13 to 50 (at idle) throttle sw: partial fuel sync: +\- coolant: 88 Charge temp: 43 spark adv: 0-26 range knock: 0-53 range egr: off

Coolwind, I'm excited to see how that might help. Interesting update on my end: I had the truck running from job to job yesterday and it was starting great. I couldn't believe it. Then I noticed that the truck wasn't getting to temperature, instead it was floating around 175*. Verified the temp with a heat gun on the themostat housing. So, I'm assuming the thermostat is stuck open and I ordered a replacement. This now brings me to this: could it be that the computer doesn't know what to do, or perhaps grossly miscalculates the values when it sees an open loop reading from the CTS? Also found a friend with an MT2500 that ill be borrowing for a few days so I can see what the sensor readings are when this tough start issue presents itself.

helpful info, thanks! Haven’t swapped the sensor yet, busy chasing the kid around the house the past few days. Hoping for time this weekend. I’ll read these documents tomorrow.

Looks to be the factory coil. Interesting point as I have a friend who’s metropolitan ran into the same issue, except in his situation it wouldn’t start at all, in fact it would die while running. In my case I can run hot all day. And after a few starting attempts, it does start and runs fine. So would repeated start attempts revive a tired coil? Could be the cause, but this just seems to be a sensor issue to me.

There absolutely has to be a cause. I’m determined to figure this out.

Can anyone chime in with a list of what’s needed from start to finish for start? For instance; Key To Start Starter must reach 300rpm CPS send signal to ECU ECU sends power to ICM for spark ECU determines fuel ratio based on: A. CTS reading B. manifold temp reading etc etc etc...

I have a spare ECT that tested as good, I’ll install that today. Still have the hot start trouble today (x3) with the IAT replaced, although it is definitely starting sooner.

with the truck completely cold, OHM at the sensor is 4 and at the diagnostic port 1.3. Also tested the IAT today which was faulty; reading significantly LOW based on temp and not climbing normally.

OHM reading is 2.4