1990 740 gle gas delivery problem?

joedrt77 · Post by **joedrt77** » 04 Oct 2016, 03:23

Hi, just got this 1990 740, previous owner replaced in tank fuel pump with kemso 340 high with 43 psi and eliminated the external fuel pump, it's kind of hard to start, seems under powered and sluggish, getting codes 232 and 221 from under hood diagnostic box, wondering if I need to put the external fuel pump back on to make it run right or if it's something else. Any ideas greatly appreciated, much thanks.

93Regina · Post by **93Regina** » 04 Oct 2016, 12:14

joedrt77 wrote:1990 740...

If fuel rail pressure is good to go at start-up, then look elsewhere....like O2 sensor, leaking injector, etc.

lummert · Post by **lummert** » 04 Oct 2016, 14:02

Fuel pump check valve?

joedrt77 · Post by **joedrt77** » 04 Oct 2016, 16:29

93Regina wrote:
joedrt77 wrote:1990 740...
If fuel rail pressure is good to go at start-up, then look elsewhere....like O2 sensor, leaking injector, etc.

I'll need to get a fuel pressure tester from parts store, I'll try to do the heat test on the O2 sensor, kind of strange, it will idle good for about 4 or 5 minutes, then just dies abruptly, just like turning the ignition off, on the tests with the on-board diagnostics, it failed the fuel injector report test, thanks for reply.

joedrt77 · Post by **joedrt77** » 04 Oct 2016, 16:30

lummert wrote:Fuel pump check valve?

Will try and check it, not sure how but I'll google it, thanks for reply.

93Regina · Post by **93Regina** » 04 Oct 2016, 19:49

joedrt77 wrote:...kind of strange, it will idle good for about 4 or 5 minutes, then just dies abruptly....

With older vehicles, I put $$$ into them so these issues don't appear. Like I replace,

FPR
CPS
Fuel Relay
Ignition Control Unit
Drive-shaft carrier bearing, and check U-Joints
Front end parts, where needed, hub bearing, or repack wheel bearings
New Bougicord ignition wires, cap, rotor, and sparks; and sometimes coil

If those two codes exist, it could be CPS, relay, O2 sensor, AMM...etc...etc

One has to start somewhere...doing a rail pressure check can determine if fuel circuit relay is shooting craps.

A trouble code may or may not point to the defective part or relay, etc. A failing AMM could be your issue...but one needs to nail down the issue.

joedrt77 · Post by **joedrt77** » 05 Oct 2016, 12:51

Now at a no start without a shot of starting fluid, have a cps on the way, still no fuel injector report with on-board diagnostic test, no test port on fuel rail for fuel pressure test, fuel pump is engaging, fuel pump relay is clicking every time I turn the key on as expected, tried to pull fp relay out, wouldn't budge, thinking fuel injectors are not firing.

joedrt77 · Post by **joedrt77** » 09 Oct 2016, 05:51

Replaced cps, think it needed it but still no start, I think the main problem is not getting 12 v at fuel injector connector, don't know what causes it tho, thanks.

joedrt77 · Post by **joedrt77** » 09 Oct 2016, 11:55

Think I have a faulty coil, can I switch it out with any old cylinder coil of the same size or are they different, I always thought all the old cylinder coils were the same, thanks.

93Regina · Post by **93Regina** » 10 Oct 2016, 15:27

joedrt77 wrote:...faulty coil..

I would suspect any 4 cylinder vehicle with an EFI system would be the quick/dirty solution.

>not getting 12 v at fuel injector connector

Radio Suppression Relay bad! Car won't Start!