88 4L Renix cranking issue

[DaveVmax]

forgot my good volt meter but i tried with my cheapo one at home and tried the cps.. it said 1 ac volts while cranking

checked map sensor also terminal B came out at 4.69 volts and terminal C came out at 4.99 volts.

is there anyway to check and see if my pickup in the distributor isnt working?

 

[Ecomike]

I'll trade my CPS for yours!!!! Hell I'll trade 2 new ones for that one, if it really is giving you 1 V?

 

[DaveVmax]

yeah thats what it read on the volt meter

what else can i check, this problem is driving me nuts.

its ONLY while cranking..when it runs it runs perfect.

ive noticed now that if i put the gas to the floor while i crank it will help it start faster.....


also wanted to add that sometimes it starts perfectly fine and other times it just cranks and bogs...

this is annoying the hell out of me...

im close to giving in and going to a shop

 

[cruiser54]

31 with vacuum. 39 without.

 

[DaveVmax]

anything else i should check?

 

[bigalpha]

Does flooring the pedal in a RENIX stop fuel injection?

 

[cruiser54]

Does flooring the pedal in a RENIX stop fuel injection?

Yes. It's a "clear flood" mode.

 

[DaveVmax]

so whats that mean? i need to floor it when i start the truck sometimes

 

[cruiser54]

so whats that mean? i need to floor it when i start the truck sometimes

You should not need to do this unless you have a problem.

 

[DaveVmax]

im out of ideas...

i dont even know where to check now....

the odd thing is it runs perfect... but starting is a different story

 

[cruiser54]

Double check the AC voltage from the CPS while cranking. Make sure you're on teh proper scale.

They will run really well without the distributor sensor working. Don't worry about that.

Cranking speed may increase with the throttle butterfly opened up and can increase CPS voltage output.........Starter bad?

 

[Ecomike]

If he has leaky fuel injectors, flooring it while cranking will help ventilate the excess gas, un-flood it and help it start too!

 

[cruiser54]

If he has leaky fuel injectors, flooring it while cranking will help ventilate the excess gas, un-flood it and help it start too!

That's a real possibility, too. But, take my advice before Mike's!!!! LOL.

 

[DaveVmax]

well i went ahead and replaced the injectors with brand new HO injectors.... no good and now the truck is hunting for idle constantly... more so when cold

 

[bigalpha]

I dont think the HO injectors are compatible?

 

[cruiser54]

I dont think the HO injectors are compatible?

I thought they had different plugs. Maybe not.

 

[Ecomike]

HO engines have a higher fuel pressure. Could you have crisscrossed connectors?

 

[Ecomike]

well i went ahead and replaced the injectors with brand new HO injectors.... no good and now the truck is hunting for idle constantly... more so when cold

Time to check the O2 sensor readings, and see if the third wire is getting 12-14 volts to the heater (large orange wire) and the second wire should have 5 volts, while the third should be near zero as it is a ground. Check the wiring for damage too, they get too close to drive shafts and e-manifolds some times.

Is the hunting problem new? Is starting problem gone?

 

[DaveVmax]

im going to tackle it this weekend. it could very well be a crossed wire though.

i think i may have mixed up the two injector plugs closest to the middle.


still left with the messed up cranking though.

 

[cruiser54]

Sometimes the injector plugs don't seat well on the injectors. Give 'em all a little nudge while you're at it. Got the color codes for the injector wiring?