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914World.com _ 914World Garage _ Fule Pump or Fuel Regulator?
Posted by: chrispovoas Aug 7 2023, 12:03 AM
Hi guys, so on my journey to get the engine running an pulling correctly I have done the following;
1) Tracked down all of the air leaks so that the engne stalls if i cover up the main air intake on the air box
2) Refurbed all 4 injectors
3) Replaced the ignition leads, Rotor and distributor cap
4) Installed refurbed AA Valve
5) Checked the spark on all leads
6) Installed new plugs
However, the engine still performs / runs like its on 3 cylinders... Once the injectors were done the engine was running sweet.. Parked the car for 2 weeks, engine back to running like a pig.. All 4 plugs were quite black (even after only running for about 3 miles in total since they were installed), which shows all 4 are getting fuel but running very rich.
If the electrics are good, then it must be fuel? Perhaps the Pump or regulator?.. Anything i can check / test by myself? as my driveway is steep and the car doesnt have the power to get up it to take it to a mechanic
Cheers
Chris
Posted by: Superhawk996 Aug 7 2023, 06:53 AM
Check cylinder head temperature sensor (CHT)
Check manifold pressure sensor (MPS).
Both of these affect mixture. Either can cause an excessive rich condition.
CHT is the most likely. MPS rebuild kits are available from Tangerine Racing.
Posted by: Superhawk996 Aug 7 2023, 06:55 AM
Brad Ander’s D-jet site is required reading and has all the information you need to test and troubleshoot components
https://members.rennlist.com/pbanders/djetfund.htm
Posted by: JeffBowlsby Aug 7 2023, 08:32 AM
Check cylinder head temperature sensor (CHT)
Check manifold pressure sensor (MPS).
Both of these affect mixture. Either can cause an excessive rich condition.
CHT is the most likely. MPS rebuild kits are available from Tangerine Racing.
^^^Agree. It may be something else but verify functionality these parts first. You wil need a Mityvac hand pump and an ohmmeter.
Posted by: brant Aug 7 2023, 09:07 AM
really start with the basics
its the only way to rule out some of the potential problems...
verify fuel pressure
adjust the valves
verify timing
but I also agree with then verifying the CHT and MPS
Posted by: chrispovoas Aug 7 2023, 11:48 PM
Check cylinder head temperature sensor (CHT)
Check manifold pressure sensor (MPS).
Both of these affect mixture. Either can cause an excessive rich condition.
CHT is the most likely. MPS rebuild kits are available from Tangerine Racing.
Cheers! But how do i "check them"? can i do via a voltage check or is there another way?
I think the running rich is an issue, but i dont think it would cause the car to have that much of a loss of power and running like a pig?
Posted by: chrispovoas Aug 7 2023, 11:49 PM
Check cylinder head temperature sensor (CHT)
Check manifold pressure sensor (MPS).
Both of these affect mixture. Either can cause an excessive rich condition.
CHT is the most likely. MPS rebuild kits are available from Tangerine Racing.
^^^Agree. It may be something else but verify functionality these parts first. You wil need a Mityvac hand pump and an ohmmeter.
Thanks Jeff, was wondering how to check....
Posted by: brant Aug 8 2023, 06:47 AM
The link above is for brad anders website
Read it 3 times
It explains all of the testing procedures and more
Adjust your valves
Check your fuel pressure
Get a Haynes manual
Check timing and spark plug order if you have touched them
You have a lot of reading to do
And a day s wrenching
Let us know what you find
Update…….
Just re read your initial post
I’m betting you have a spark plug wire in the wrong order
Check your firing order
did you pull the distributor... it could be indexed wrong... so check firing order by verifying the motor is on TDC and then look at the rotor under the cap…for that position to be plug wire for cylinder #1 (you can verify TDC and adjust valves at the same time)
It’s almost always the last thing touched by an owner causing the problem
Brant
Posted by: dr914@autoatlanta.com Aug 8 2023, 09:01 AM
what year and engine size?
Hi guys, so on my journey to get the engine running an pulling correctly I have done the following;
1) Tracked down all of the air leaks so that the engne stalls if i cover up the main air intake on the air box
2) Refurbed all 4 injectors
3) Replaced the ignition leads, Rotor and distributor cap
4) Installed refurbed AA Valve
5) Checked the spark on all leads
6) Installed new plugs
However, the engine still performs / runs like its on 3 cylinders... Once the injectors were done the engine was running sweet.. Parked the car for 2 weeks, engine back to running like a pig.. All 4 plugs were quite black (even after only running for about 3 miles in total since they were installed), which shows all 4 are getting fuel but running very rich.
If the electrics are good, then it must be fuel? Perhaps the Pump or regulator?.. Anything i can check / test by myself? as my driveway is steep and the car doesnt have the power to get up it to take it to a mechanic
Cheers
Chris
Posted by: chrispovoas Aug 8 2023, 10:05 PM
The link above is for brad anders website
Read it 3 times
It explains all of the testing procedures and more
Adjust your valves
Check your fuel pressure
Get a Haynes manual
Check timing and spark plug order if you have touched them
You have a lot of reading to do
And a day s wrenching
Let us know what you find
Update…….
Just re read your initial post
I’m betting you have a spark plug wire in the wrong order
Check your firing order
did you pull the distributor... it could be indexed wrong... so check firing order by verifying the motor is on TDC and then look at the rotor under the cap…for that position to be plug wire for cylinder #1 (you can verify TDC and adjust valves at the same time)
It’s almost always the last thing touched by an owner causing the problem
Brant
Hi Brant.. Left it overnight and it spluttered into life.. I also thought the leads were on the wrong way round! but an overnights nap seems to have sorted the starting issue.
Next step will be fuel pressure! Will let you know how i get on!
Cheers
Posted by: r_towle Aug 8 2023, 10:12 PM
What year, engine, size, and fuel injection type?
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