Fuching DJet issues *SOLVED*, Running out of things to try |
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Fuching DJet issues *SOLVED*, Running out of things to try |
rjames |
Jun 12 2019, 12:19 AM
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#1
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I'm made of metal Group: Members Posts: 3,916 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
Last summer all of a sudden my car wouldn’t stay running. If I could get it started the idle would hunt and the car would die unless I kept on the gas. Lack of power at times. All somewhat erratic.
Found that the MPS wouldn’t hold vacuum. Replaced the bad mps with a known good one. Car idles high when cold (higher than I think it should ~1600 rpm) so AAR is good, then when it warms up idle hunts from ~900rpm to the point where it almost dies unless I open the throttle body bleed screw quite a bit and turn the ECU knob just a few clicks away from full clockwise. So I did the following hoping to fix the issue: Replaced all vac hoses including intake runner to plenum hoses. New intakecrunner gaskets Verified plenum isn’t leaking New throttle body gasket Installed NOS throttle body Rebuilt the distributor New condenser Rebuilt injectors and flow tested New fuel lines Fuel pump is less than 2 years old Set timing and dwell with advance disconnected New CHT (resistance reads 1.7 w/engine off @70 degrees in the garage) Calibrated the TPS, even unplugged it to take it out of the equation, didn’t change anything. ECU matches the MPS (both correct part #s for a ‘75 2.0) Tried a known good ECU from a ‘74, no change. Feels like the MPS needs to be calibrated...but then again, these are all the same symptoms I had with the old bad mps. Replacement mps is from a Jeff B and was tested, but I haven’t retested it to see if it’s holding vacuum. (Don’t have the necessary tool, but maybe that’s the next step) Help! What am I missing? |
JeffBowlsby |
Jun 20 2019, 09:16 PM
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#2
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914 Wiring Harnesses Group: Members Posts: 8,479 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
No effect during adjusting the air screw points to a vacuum leak.
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rjames |
Jun 20 2019, 10:45 PM
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#3
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I'm made of metal Group: Members Posts: 3,916 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
No effect during adjusting the air screw points to a vacuum leak. There is effect- I can increase the rpm, just can’t get it down past 1500. If there was a vacuum leak, why would the rpms drop to 900 and fluctuate down to almost 0 when connecting the line to the distributor? Wouldn’t the rpms stay up? At least enough to keep it running without opening up the TB screw a ton? Seems odd that’s it would do exactly what it did when my original MPS failed, especially after replacing all vacuum lines, gaskets, intake boots, injector seals, verifying no leaks in plenum and installing a NOS throttle body. |
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